IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD
Replacement processing is executed when the number of times of permission for a pixel corresponding to an ejection defective nozzle in a mask pattern is larger than a smallest number of times of permission, of the numbers of times of permission for pixels corresponding to ejection normal nozzles.
This application is a division of U.S. patent application Ser. No. 15/090,998, filed Apr. 5, 2016, which claims the benefit of Japanese Patent Application No. 2015-079488, filed Apr. 8, 2015, both of which are hereby incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION Field of the InventionThe present invention relates to an image processing apparatus and an image processing method.
Description of the Related ArtImage printing apparatuses that print an image by repetitively performing print scanning that ejects inks while relatively moving a printing head having a plurality of ejection ports with respect to a unit area of a printing medium, the ejection ports ejecting inks being arrayed, and sub scanning that conveys the printing medium are known. In such image printing apparatuses, so-called multipass printing method is known, which forms an image by performing a plurality of times of print scanning for the unit area. In a conventional multipass printing method, print data to be used in printing in a plurality of times of scanning is generated by dividing the image data into a plurality of times of scanning, using image data having one-bit information for determining ejection or non-ejection of ink for each pixel, and a plurality of mask patterns including one-bit information for determining permission or non-permission of ejection of ink for each pixel and corresponding to the plurality of times of scanning.
In an image printing apparatus that performs the above-described multipass printing method, when ejection failure of ink has occurred in a certain ejection port of the plurality of ejection ports, degradation of image quality of an image to be obtained is known. In contrast, Japanese Patent Application Laid-Open No. 2000-094662 describes replacement of information of a pixel in a mask pattern corresponding to the ejection port in which the ejection failure has occurred with information of a pixel in a mask pattern corresponding to another ejection port that can eject the ink to the same pixel region. Accordingly, even if the ejection failure is caused in the ejection port, complement printing can be performed through a different ejection port. Therefore, the degradation of the image quality can be suppressed.
Further, in recent years, generation of print data using image data having multiple-bit information for determining the number of times of ejection of ink for each pixel, and a mask pattern having multiple-bit information for determining the number of times of permission of ejection of ink for each pixel is known. By generating the print data as described above, the ink can be ejected to one pixel region a plurality of times. Japanese Patent Application Laid-Open No. 2003-175592 discloses complement printing for an ejection port in which the ejection failure has occurred, using image data having two-bit information and a mask pattern. In more detail, when the ejection failure has occurred in a certain ejection port, a pixel having the number of times of permission of ejection of ink being zero times is determined from pixels in a mask pattern corresponding to other ejection ports that can eject the ink to the same pixel region as the certain ejection port. Then, the complement printing is performed by replacing the information of the number of times of permission of ejection of ink being zero times in the pixel using information of a pixel in a mask pattern corresponding to the ejection port in which the ejection failure has occurred.
However, according to the technology described in Japanese Patent Application Laid-Open No. 2003-175592, in a form of ejecting the ink to one pixel region a plurality of times using the image data having the multiple-bit information and the mask pattern, favorably complement printing may not be able to be performed in a case where the ejection failure of an ejection port has occurred.
For example, in a print mode having a small scan amount for a unit area, or the like, there is a case of using a mask pattern that permits at least once ejection of ink for all of a plurality of pixels in mask patterns corresponding to a plurality of ejection ports that can eject an ink to the same pixel region. If the ejection failure is caused in a certain ejection port, no information of the number of times of permission of ejection of ink being zero times exists in the pixels in the mask patterns corresponding to the ejection ports that can eject an ink to the same pixel region, the replacement described in Japanese Patent Application Laid-Open No. 2000-094662 may not be able to be executed.
Further, even in a case of using a mask pattern in which the information of the number of times of permission of ejection of ink being zero times is determined for x pixels, of the plurality of pixels in the mask patterns corresponding to the plurality of ejection ports that can eject an ink to the same pixel region, favorably complement printing may not be able to be performed. In more detail, when the ejection failure is caused in y ejection ports, which is larger than X, of the plurality of ejection ports, replacement destinations of information in pixels corresponding to (y−x) ejection ports in which the ejection failure has been caused do not exist. Therefore, the replacement described in Japanese Patent Application Laid-Open No. 2000-094662 cannot be executed.
SUMMARY OF THE INVENTIONThe present invention has been made in view of the above. Embodiments of the invention include generating print data to be used in printing, which enables favorably complement printing when ejection failure of an ejection port is caused even in a case of performing printing to eject an ink to one pixel region a plurality of times.
An example of the present invention is an image processing apparatus that generates print data using a printing head having an ejection port array in which a plurality of ejection ports for ejecting inks is arrayed in a predetermined direction, the print data using the printing head in each of K (K≧3) times of relative scanning to a unit area on a printing medium in a crossing direction intersecting with the predetermined direction, and the print data determining ejection or non-ejection of ink to each of pixel-equivalent pixel regions in the unit area, the image processing apparatus including: a first acquiring unit configured to acquire image data in which information indicating the number of times of ejection of ink from zero to N (2≦N≦K) times for each of the plurality of pixel regions is determined for each pixel; a storage unit configured to store a first mask pattern in which information indicating the number of times of permission of ejection of ink from 0 to M (2≦M≦K) times for each of the plurality of pixel regions is determined for each pixel; a specifying unit configured to specify the first ejection port in which ejection failure of ink exists, of the plurality of ejection ports; a first selecting unit configured to select the information indicating the number of times of permission in the K pixels, of the information determined by the first mask pattern stored in the storage unit, the K pixels corresponding to K different ejection ports including at least the first ejection port specified by the specifying unit and capable of ejecting the inks to a same position to each other in the K times of scanning, and the K pixels being positioned in a same position to each other in the crossing direction; a second acquiring unit configured to acquire the information indicating the number of times of permission in a pixel corresponding to the first ejection port specified by the specifying unit, of the information selected by the first selecting unit; a third acquiring unit configured to acquire the information indicating the number of times of permission in a pixel corresponding to the second ejection port not specified by the specifying unit, of the information selected by the first selecting unit; a second selecting unit configured to select the first information having a smallest number of times of permission indicated by the information, from the information acquired by the third acquiring unit; a first generating unit configured to generate a second mask pattern by replacing the first information selected by the second selecting unit using the information acquired by the second acquiring unit when the number of times of permission indicated by the information acquired by the second acquiring unit is larger than the number of times of permission indicated by the first information selected by the second selecting unit; and second generating unit configured to generate the print data based on the image data acquired by the first acquiring unit, and the second mask pattern generated by the first generating unit.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
First EmbodimentA platen 2 is arranged inside the image printing apparatus 1000, and a large number of suction holes 34 are formed in the platen 2 to adsorb a printing medium 3 and not to allow the printing medium 3 to rise up. These suction holes 34 are linked with a duct, and a suction fan 36 is arranged below the duct and operated, so that the printing medium 3 is adsorbed to the platen 2.
A carriage 6 is configured to be supported by a main rail 5 installed extending in a sheet width direction, and is reciprocally moved in an X direction (crossing direction). The carriage 6 mounts a printing head 7 in an ink jet system described below. Note that various printing systems are applicable to the printing head 7, such as a thermal jet system using a heating element, and a piezo system using a piezoelectric transducer. A carriage motor 8 is drive source for moving the carriage 6 in the X direction, and rotational driving force thereof is transmitted to the carriage 6 with a belt 9.
The printing medium 3 is fed by being wound from a medium 23 rolled in a roll manner. The printing medium 3 is conveyed in a Y direction (conveying direction) intersecting with the X direction on the platen 2. A tip of the printing medium 3 is pinched by a pinch roller 16 and a conveying roller 11, and the conveying roller 11 is driven, so that conveyance is performed. Further, the printing medium 3 is pinched by a roller 31 and a discharge roller 32 at a downstream of the platen 2 in the Y direction, and is wound around a winding roller 24 through a turn roller 33.
The printing head 7 is configured such that eleven ejection port arrays 22Y, 22M, 22Pm, 22C, 22Pc, 22Bk, 22Gy, 22Pgy, 22R, 22B, and 22P (hereinafter, one of these ejection port arrays is also referred to as ejection port array 22) are arranged side by side in this order in the X direction, the eleven ejection port arrays being able to respectively discharge inks of yellow (Y), magenta (M), photo magenta (Pm), cyan (C), photo cyan (Pc), black (Bk), gray (Gy), photo gray (Pgy), red (R), and blue (B), and processing liquids (P) having purposes other than coloring, such as protection of a printing surface and improvement of gloss. These ejection port arrays 22 are configured such that 1280 ejection ports (hereinafter, also referred to as nozzles) 30 that eject respective inks are arrayed in the Y direction (predetermined direction) with density of 1200 dpi. Note that the ejection ports 30 in mutually adjacent positions in the Y direction are arranged in mutually shifted positions in the X direction. Here, an ejection amount of ink ejected through one ejection port 30 at a time in the present embodiment is about 4.5 ng.
These ejection port arrays 22 are connected to ink tanks (not illustrated) that respectively store corresponding inks, and supply the inks. Note that the printing head 7 and the ink tanks used in the present embodiment may be integrally configured, or may be separably configured.
In the present embodiment, an image is formed according to a multipass printing method that performs printing in a unit area by a plurality of times (K times) of scanning. Further, in the present embodiment, as the multipass printing method, at least two methods including a four-pass printing method that performs printing by four times of scanning to the unit area on a printing medium, and a three-pass printing method that performs printing by three times of scanning to a unit area on a printing medium are executable. Hereinafter, the multipass printing method will be described in detail using the four-pass printing method as an example.
The ejection ports 30 that eject the inks and are provided in an ejection port array 22 are divided into four ejection port groups 201, 202, 203, and 204 along a sub scanning direction.
In the print scanning of the first time (1 pass), the ink is ejected through the ejection port group 201 to a unit area 211 on the printing medium 3.
Next, the printing medium 3 is relatively conveyed with respect to the printing head 7 from an upstream side to a downstream side in the Y direction by a distance of L/4. Here, for simplification, a case of conveying the printing head 7 with respect to the printing medium 3 from the downstream side to the upstream side in the Y direction is illustrated. However, a relative positional relationship between the printing medium 3 and the printing head 7 after conveyance is the same as the case of conveying the printing medium 3 toward the downstream side in the Y direction.
Following that the print scanning of the second time is performed. In the print scanning of the second time (2 pass), the ink is ejected through the ejection port group 202 to a unit area 211 on the printing medium, and the ink is ejected through the ejection port group 201 to a unit area 212 on the printing medium.
Hereinafter, the print scanning with the printing head 7 and the relative conveyance of the printing medium 3 are alternately repeated. As a result, after the print scanning of the fourth time (4 pass) is performed, the inks have been ejected to the unit area 211 of the printing medium 3 through the ejection port groups 201 to 204 once each.
Note that, here, the four-pass printing method has been described. However, the three-pass printing method can also be performed by similar processes.
In the present embodiment, in the above multipass printing method, one-bit print data to be used in printing in each scanning is generated from image data using image data having a-bit (a≧2) information, a mask pattern having b-bit (b≧2) information, a decoding table that defines ejection or non-ejection of ink according to a combination of values indicated by the multi-bit information in the image data and the mask patterns. Note that, in the following description, a case in which both the image data and the mask patterns are configured from two-bit information will be described.
(Four-Pass Printing Method)Further, in the present embodiment, a maximum value of the number of times of ejection of ink reproduced by the image data having a-bit information is (2̂a)−1 times. In the present embodiment, a=2, and thus the maximum value of the number of times of ejection of ink to be expressed is 3 (=(2̂2)−1) times that is a value obtained by subtracting 1 from the square of 2.
To be specific, when a value (hereinafter, also referred to as pixel value) indicated by two-bit information that configures image data corresponding to a certain pixel is “00”, the ink is not ejected to the pixel even once. Further, when the pixel value is “01”, the ink is ejected to the corresponding pixel once. Further, when the pixel value is “10”, the ink is ejected to the corresponding pixel twice. Further, when the pixel value is “11”, the ink is ejected to the corresponding pixel three times. As described above, in the image data in the present embodiment, one of the number of times of ejection from zero to three times is determined for each pixel.
As for the image data illustrated in
Here, any of the four (=2̂b) ways of values of “00”, “01”, “10”, and “11” is allocated to each pixel in the mask patterns illustrated in
Here, as can be seen by reference to the decoding table illustrated in
Meanwhile, as can be seen by reference to the decoding table illustrated in
Further, when the code value is “10”, the ink is not ejected when the pixel value in the corresponding pixel is “00” or “01”, but the ink is ejected when the pixel value is “10” or “11”. That is, the code value of “10” corresponds to the ejection of ink being permitted for the four ways of pixel values twice (the number of times of permission of ejection of ink is twice).
Further, when the code value is “11”, the ink is not ejected when the pixel value in the corresponding pixel is “00”, but the ink is ejected when the pixel value is “01”, “10”, or “11”. That is, the code value of “11” corresponds to the ejection of ink being permitted for the four ways of pixel values three times (the number of times of permission of ejection of ink is three times). Note that the pixel in the mask pattern to which any of the three (=2̂b−1) ways of code values of “01”, “10”, and “11” is allocated is also referred to as print permitting pixel in the following description.
As described above, in the mask patterns in the present embodiment, any of the numbers of times of permission from zero to three times is determined for each pixel.
Here, the mask patterns having multiple-bit information to be used in the four-pass printing method in the present embodiment are set based on (condition 1) and (condition 2) below.
(Condition 1)Here, ((2̂b)−1) print permitting pixels are arranged in a plurality of pixels in the same positions in a plurality of mask patterns. These ((2̂b)−1) print permitting pixels permit the ejection of ink by different numbers from each other. To be specific, since b=2 in the present embodiment, any of the code values “01”, “10”, and “11” is allocated to each of three (=2̂2−1) pixels of the four pixels in the same positions in the four mask patterns respectively illustrated in
For example, to the pixel 700, the code value of “01” is allocated in the mask pattern illustrated in
Further, to the pixel 701, the code value of “01” is allocated in the mask pattern illustrated in
With such a configuration, even if the pixel value in a certain pixel is any of “00”, “01”, “10”, and “11”, the print data for ejecting an ink to the pixel region corresponding to the pixel by the number of times of ejection of ink corresponding to the pixel value can be generated.
(Condition 2)Further, the print permitting pixels corresponding to the code value of “01” are arranged in the mask patterns illustrated in
Similarly, the pint permitting pixels corresponding to the code value of “10” are arranged in the mask patterns respectively illustrated in
Here, a case in which the same number of the print permitting pixels respectively corresponding to the code values “01”, “10”, and “11” are arranged in the respective mask patterns has been described. However, in reality, nearly the same number may just be arranged to each other.
Accordingly, printing rates in the four times of scanning can be nearly equal to one another, in distributing the image data into the four times of scanning and generating the print data using the mask patterns respectively illustrated in
For example, in the pixel 700 in the print data corresponding to the scanning of the first time illustrated in
The ink is ejected in the scanning of the first to fourth times according to the print data generated as described above and illustrated in
For example, in the pixel 700, the ejection of ink is determined in the print data corresponding to the scanning of the first, second, and third times illustrated in
Further, in the pixel 701, the ejection of ink is determined in the print data corresponding to the scanning of the first and fourth times illustrated in
When comparing the print data illustrated in
According to the above configuration, in the four-pass printing method, the one-bit print data to be used in the four times of scanning can be generated based on the image data and the mask patterns having multiple-bit information.
(Three-Pass Printing Method)Here, the mask patterns having multiple-bit information to be used in the three-pass printing method in the present embodiment are set based on (condition 1′) and (condition 2′) below.
(Condition 1′)Similarly to the (condition 1) in the four-pass printing method, the ((2̂b)−1) print permitting pixels are arranged in a plurality of pixels in the same positions in a plurality of mask patterns, and the ((2̂b)−1) print permitting pixels permit ejection of ink by mutually different numbers. To be specific, any of the code values of “01”, “10”, and “11” is allocated to each of three (=2̂2−1) pixels in the same position in the three mask patterns illustrated in
For example, to the pixel 800, the code value of “01” is allocated in the mask pattern illustrated in
Further, to the pixel 806, the code value of “01” is allocated in the mask pattern illustrated in
With such a configuration, even if the pixel value in a certain pixel is any of “00”, “01”, “10”, and “11”, the print data for ejecting an ink to a pixel region corresponding to the pixel by the number of times of ejection of ink corresponding to the pixel value can be generated.
(Condition 2′)Further, the print permitting pixels corresponding to the code value of “01” are arranged in the mask patterns respectively illustrated in
Similarly, the print permitting pixels corresponding to the code value of “10” are arranged in the mask patterns respectively illustrated in
Accordingly, printing rates in the three times of scanning can be nearly equal to one another in distributing the image data into the three times of scanning and generating the print data using the mask patterns respectively illustrated in
For example, in the pixel 800 in the print data corresponding to the scanning of the first time illustrated in
The ink is ejected in the scanning of the first to third times according to the print data generated as described above and illustrated in
For example, in the pixel 800, the ejection of ink is determined in the print data corresponding to the scanning of the first, second, and third times illustrated in
Further, in the pixel 806, the ejection of ink is determined in the print data corresponding to the scanning of the third time illustrated in
When comparing the print data illustrated in
According to the above configuration, in the three-pass printing method, the one-bit print data to be used in the three times of scanning can be generated based on the image data and the mask patterns having multiple-bit information.
The degradation of the image quality in a case where the ejection failure of ink has occurred in one ejection port, in using the image data and the mask patterns having multiple bit-information will be described.
Normally, in a region 211a, the ink can be ejected through ejection ports 30a to 30d four times in total in the scanning of the first to fourth times. However, when the ejection port 30a is the ejection defective nozzle, even if the print data is determined to eject the ink through the ejection port 30a, the ink is not ejected to the region 211a in the scanning of the first time, and the ink is ejected up to three times. Therefore, a desired number of ejection may not be able to be obtained in the region 211a.
Here, as can be seen from
Meanwhile, while the ideal number of times of ejection is three times, as illustrated in
Similarly, while the ideal number of times of ejection of ink illustrated in
Further, in a case of using the image data and the mask patterns illustrated in
Here, as can be seen from
Meanwhile, while the ideal number of times of ejection of ink is three times, as illustrated in
As described above, when the ejection failure of ink has occurred, a gap may be caused from the ideal number of times of ejection in both of the four-pass printing method and the three-pass printing method, and the image quality of an image may be degraded.
(Non-Ejection Complementary Processing)In view of the foregoing, in the present embodiment, when the ejection failure of ink is caused, processing of modifying the code value in the pixel corresponding to the ejection port in which the ejection failure of ink has occurred in the mask pattern (hereinafter, the processing is also referred to as non-ejection complementary processing) is executed. That is, processing of allocating a code value of a complementary source pixel that is the pixel corresponding to the ejection defective nozzle to a complementary destination pixel that is the pixel corresponding to the ejection normal nozzle is performed. Accordingly, even in a case where the ejection failure of ink is caused, the printing can be performed such that the gap from the ideal number of times of ejection becomes small.
Note that the non-ejection complementary processing in the present embodiment is performed before printing to the printing medium is started. However, in a case where the mask pattern to be applied is changed for each region to be printed, the non-ejection complementary processing may be performed in the process of the printing. Further, the non-ejection complementary processing may be performed for the mask pattern corresponding to the region to be printed before the start of the printing, and the corresponding mask pattern for which the non-ejection complementary processing has been executed may be read for each region to be printed.
In step S701, the ejection defective nozzle data stored in the memory 313 is read, and the information for identifying the ejection port in which the ejection failure of ink exists is acquired. Note that the ejection defective nozzle data can be generated by various methods. For example, the ejection defective nozzle data obtained by printing a test pattern to eject the ink through all the ejection ports before execution of the non-ejection complementary processing, and identifying the ejection defective nozzle based on the test pattern can be used. Further, in the process of using an ink jet printing apparatus 100, the position or the number of the ejection defective nozzles may be changed. To follow such change, the ejection defective nozzle data may be updated based on information detected in a recovery operation, a preliminary ejection operation, and the like in a home position of a printing head 111.
In step S702, about a pixel group made of a plurality of pixels in the same position to each other in the plurality of mask patterns (for example, a pixel group made of the pixels 700 in the respective mask patterns illustrated in
Next, in step S703, the code value of the complementary source candidate pixel (first candidate pixel) corresponding to the ejection defective nozzle of the complementary pixel group selected in step S702 is acquired. At this time, in a case where only one complementary source candidate pixel corresponding to the ejection defective nozzle exists in the complementary pixel group selected in step S702, one code value is acquired. In a case where a plurality of complementary source candidate pixels corresponding to the ejection defective nozzle exists, the code values in the respective complementary source candidate pixels are acquired.
Next, in step S704, one code value is selected from the code values of the complementary source candidate pixels acquired in step S703, as a code value A of the complementary source pixel (first pixel) to be used in the processing described below. Here, in a case where a plurality of code values has been acquired in step S703, one code value is randomly selected from the plurality of code values in step S704 in the present embodiment, and the code value is determined as the code value A.
Next, in step S705, a code value of the complementary destination candidate pixel (second candidate pixel) corresponding to a nozzle other than the ejection defective nozzle (hereinafter, the nozzle is also referred to as ejection normal nozzle) of the complementary pixel group selected in step S702 is acquired. At this time, in a case where only one complementary destination candidate pixel corresponding to the ejection normal nozzle exists in the complementary pixel group selected in step S702, one code value is acquired. Further, in a case where a plurality of complementary destination candidate pixels corresponding to the ejection normal nozzle exists, the code values in the respective complementary destination candidate pixels are acquired.
Next, in step S706, one code value is selected from the code values of the complementary destination candidate pixels acquired in step S705, as a code value B of the complementary destination pixel (second pixel) describe below is selected. Here, in step S704 in the present embodiment, the code value that indicates the smallest number of times of permission of ejection of ink, of the code values of the complementary destination candidate pixels acquired in step S705, is selected and is used as the code value B of the complementary destination pixel.
As described using the decoding table illustrated in
Therefore, for example, when the code values of the complementary destination candidate pixel acquired in step S705 are “00” and “11”, the code value of “00” is selected as the code value B of the complementary destination pixel in step S706. Further, for example, when the code values of the complementary destination candidate pixel acquired in step S705 are “01”, “10”, “11”, the code value of “01” is selected as the code value B of the complementary destination pixel in step S706. Further, for example, when the code value of the complementary destination candidate pixel acquired in step S705 is only “10”, the code value of “10” is selected as the code value B of the complementary destination pixel in step S706.
Next, in step S707, comparison of the code value A selected in step S704 and the code value B selected in step S706 is performed. Here, when the number of times of permission of ejection of ink indicated by the code value A is larger than that indicated by the code value B, the processing proceeds to step S708, and the processing of replacing the code value B determined to the complementary destination pixel with the code value A determined to the complementary source pixel is performed. Meanwhile, when the number of times of permission of ejection of ink indicated by the code value A is smaller than that indicated by the code value B, the replacement processing is not executed.
For example, when the code value A selected in step S704 is “11” and the code value B selected in step S706 is “00”, the number of times of permission (three times) indicated by the code value A is larger than the number of times of permission (zero times) indicated by the code value B. Therefore, the code value B of “00” of the complementary destination pixel is replaced with the code value of “11” of the complementary source pixel in step S708. Further, when the code value A is “10” and the code value B is “01”, the number of times of permission (twice) indicated by the code value A is larger than the number of times of permission (once) indicated by the code value B. Therefore, the code value B of “01” of the complementary destination pixel is replaced with the code value of “10” of the complementary source pixel. Further, when the code value A is “01” and the code value B is “11”, the number of times of permission (once) indicated by the code value A is smaller than the number of times of permission (three times) indicated by the code value B. Therefore, the replacement processing is not performed, and the original “11” is determined without change as the code value of the complementary destination pixel.
Next, in step S709, whether a complementary source candidate pixel for which the processing in steps S704 to S708 has not yet been executed exists in the complementary pixel group selected in step S702 is determined. When it is determined that the processing in steps S704 to S708 has been executed for all the complementary source candidate pixels, the processing proceeds to step S710.
Meanwhile, when it is determined that remaining complementary source candidate pixels for which the processing in steps S704 to S708 has not yet been performed exist, the processing returns to step S704, and processing similar to the processing in steps S704 to S708 is executed for the remaining complementary source candidate pixels. Here, in the present embodiment, a complementary destination pixel for which replacement has been executed even once in step S708 in one complementary pixel group is excluded from the complementary destination candidate pixels in step S705 in the subsequent processing.
Then, in step S710, whether the processing in steps S703 to S709 has been executed for all the complementary pixel groups that include at least one pixel corresponding to the ejection defective nozzle is determined. When it is determined that the complementary pixel groups for which the processing in steps S703 to S709 has not yet been executed remain, the processing returns to S702, and the processing in steps S703 to S709 is executed for all the remaining complementary pixel groups.
Meanwhile, when it is determined that the processing in steps S703 to S709 has been executed for all the complementary pixel groups, the non-ejection complementary processing is terminated, and a finally obtained mask pattern is updated as a mask pattern to be used for generation of print data.
(Non-Ejection Complementary Processing in Four-Pass Printing Method)A process in executing the non-ejection complementary processing (S701 to S710) illustrated in
Here, in a case where the ejection defective nozzle 30a illustrated in
In the first complementary pixel group, the pixel 700 corresponding to the ejection defective nozzle is included only in the mask pattern 505 corresponding to the scanning of the first time. Therefore, in step S703, the code value “11” of the pixel 700 in the mask pattern 505 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “11” of the pixel 700 in the mask pattern 505 corresponding to the scanning of the first time is selected as the code value A.
Further, in the first complementary pixel group, the pixel 700 corresponding to the ejection normal nozzle is included in the mask patterns 506, 507, and 508 corresponding to the scanning of the second, third, and fourth times. Therefore, in step S705, three code values including the code value “10” of the pixel 700 in the mask pattern 506 corresponding to the scanning of the second time, the code value “01” of the pixel 700 in the mask pattern 507 corresponding to the scanning of the third time, and the code value “00” of the pixel 700 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “00” of the pixel 700 in the mask pattern 508 corresponding to the scanning of the fourth time, which indicates the smallest number of times of permission of ejection of ink in the three code value, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (three times) indicated by the code value “11” of the pixel 700 in the mask pattern 505 as the code value A is larger than the number of times of permission (zero times) indicated by the code value “00” of the pixel 700 in the mask pattern 508 as the code value B. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the first complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the first complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining second, third, and fourth complementary pixel groups, the processing returns to step S704.
Next, a case in which the second complementary pixel group made of four pixels 701 in the mask patterns 505 to 508 is selected from the remaining second, third, and fourth complementary pixel groups in step 704 will be described.
In the second complementary pixel group, the pixel 701 corresponding to the ejection defective nozzle is included only in the mask pattern 505 corresponding to the scanning of the first time. Therefore, in step S703, the code value “10” of the pixel 701 in the mask pattern 505 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “10” of the pixel 701 in the mask pattern 505 corresponding to the scanning of the first time is selected as the code value A.
Further, in the second complementary pixel group, the pixel 701 corresponding to the ejection normal nozzle is included in the mask patterns 506, 507, and 508 corresponding to the scanning of the second, third, and fourth times. Therefore, in step S705, three code values including the code value “01” of the pixel 701 in the mask pattern 506 corresponding to the scanning of the second time, the code value “00” of the pixel 701 in the mask pattern 507 corresponding to the scanning of the third time, and the code value “11” of the pixel 701 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “00” of the pixel 701 in the mask pattern 507 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink in the three code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (twice) indicated by the code value “10” of the pixel 701 in the mask pattern 505 as the code value A is larger than the number of times of permission (zero times) indicated by the code value “00” of the pixel 701 in the mask pattern 507 as the code value B. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the second complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the second complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining third and fourth complementary pixel groups, the processing returns to step S704.
Next, a case in which the third complementary pixel group made of four pixels 702 in the mask patterns 505 to 508 is selected from the remaining third and fourth complementary pixel groups in step 704 will be described.
In the third complementary pixel group, the pixel 702 corresponding to the ejection defective nozzle is included only in the mask pattern 505 corresponding to the scanning of the first time. Therefore, in step S703, the code value “01” of the pixel 702 in the mask pattern 505 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “01” of the pixel 702 in the mask pattern 505 corresponding to the scanning of the first time is selected as the code value A.
Further, in the third complementary pixel group, the pixel 702 corresponding to the ejection normal nozzle is included in the mask patterns 506, 507, and 508 corresponding to the scanning of the second, third, and fourth times. Therefore, in step S705, three code values including the code value “00” of the pixel 702 in the mask pattern 506 corresponding to the scanning of the second time, the code value “11” of the pixel 702 in the mask pattern 507 corresponding to the scanning of the third time, and the code value “10” of the pixel 702 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “00” of the pixel 702 in the mask pattern 506 corresponding to the scanning of the second time, which indicates the smallest number of times of permission of ejection of ink in the three code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (once) indicated by the code value “01” of the pixel 702 in the mask pattern 505 as the code value A is larger than the number of times of permission (zero times) indicated by the code value “00” of the pixel 702 in the mask pattern 506 as the code value B. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the third complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the third complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining fourth complementary pixel group, the processing returns to step S704.
Next, a case in which the fourth complementary pixel group made of four pixels 703 in the mask patterns 505 to 508 is selected in step 704 will be described.
In the fourth complementary pixel group, the pixel 703 corresponding to the ejection defective nozzle is included only in the mask pattern 505 corresponding to the scanning of the first time. Therefore, in step S703, the code value “00” of the pixel 703 in the mask pattern 505 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “00” of the pixel 703 in the mask pattern 505 corresponding to the scanning of the first time is selected as the code value A.
Further, in the fourth complementary pixel group, the pixel 703 corresponding to the ejection normal nozzle is included in the mask patterns 506, 507, and 508 corresponding to the scanning of the second, third, and fourth times. Therefore, in step S705, three code values including the code value “11” of the pixel 703 in the mask pattern 506 corresponding to the scanning of the second time, the code value “10” of the pixel 703 in the mask pattern 507 corresponding to the scanning of the third time, and the code value of “01” of the pixel 703 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “01” of the pixel 703 in the mask pattern 508 corresponding to the scanning of the fourth time, which indicates the smallest number of times of permission of ejection of ink in the three code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (zero times) indicated by the code value “00” of the pixel 703 in the mask pattern 505 as the code value A is smaller than the number of times of permission (once) indicated by the code value “01” of the pixel 703 in the mask pattern 508 as the code value B. Therefore, the replacement processing in step S708 is not executed. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the fourth complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the fourth complementary pixel group by the above-described processing in step S709. Then, in step S710, it is determined that the non-ejection complementary processing has been executed in all the complementary pixel groups, and the non-ejection complementary processing is terminated.
As can be seen from
By use of the mask pattern after the non-ejection complementary processing in the present embodiment is executed, when compared with the print data illustrated in
Therefore, as illustrated in
Here, while the ejection (“1”) of ink is determined in the pixels 700 and 701 in the print data corresponding to the scanning of the first time illustrated in
Next, a process of when the non-ejection complementary processing illustrated in
Here, in a case where the ejection defective nozzle 30a as illustrated in
In the first complementary pixel group, the pixel 800 corresponding to the ejection defective nozzle is included only in the mask pattern 605 corresponding to the scanning of the first time. Therefore, in step S703, the code value “11” of the pixel 800 in the mask pattern 605 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “11” of the pixel 800 in the mask pattern 605 corresponding to the scanning of the first time is selected as the code value A.
Further, in the first complementary pixel group, the pixel 800 corresponding to the ejection normal nozzle is included in the mask patterns 606 and 607 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “10” of the pixel 800 in the mask pattern 606 corresponding to the scanning of the second time, and the code value “01” of the pixel 800 in the mask pattern 607 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “01” of the pixel 800 in the mask pattern 607 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink of the two code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (three times) indicated by the code value “11” of the pixel 800 in the mask pattern 605 as the code value A is larger than the number of times of permission (once) indicated by the code value “01” of the pixel 800 in the mask pattern 607 as the code value B. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the first complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the first complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining second, third, and fourth complementary pixel groups, the processing returns to step S704.
Next, a case in which the second complementary pixel group made of three pixels 801 in the mask patterns 605 and 608 is selected from the second, third, and fourth complementary pixel groups in step S704 will be described.
In the second complementary pixel group, the pixel 801 corresponding to the ejection defective nozzle is included only in the mask pattern 605 corresponding to the scanning of the first time. Therefore, in step S703, the code value “10” of the pixel 801 in the mask pattern 605 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “10” of the pixel 801 in the mask pattern 605 corresponding to the scanning of the first time is selected as the code value A.
Further, in the second complementary pixel group, the pixel 801 corresponding to the ejection normal nozzle is included in the mask patterns 606 and 607 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “01” of the pixel 801 in the mask pattern 606 corresponding to the scanning of the second time, and the code value “11” of the pixel 801 in the mask pattern 607 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “01” of the pixel 701 in the mask pattern 606 corresponding to the scanning of the second time, which indicates the smallest number of times of permission of ejection of ink in the two code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (twice) indicated by the code value “10” of the pixel 801 in the mask pattern 605 as the code value A is larger than the number of times of permission (once) indicated by the code value “01” of the pixel 801 in the mask pattern 606 as the code value B. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixels in the second complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the second complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining third and fourth complementary pixel groups, the processing returns to step S704.
Next, a case in which the third complementary pixel group made of three pixels 802 in the mask patterns 605 to 607 of the remaining third and fourth complementary pixel groups is selected in step S704 will be described.
In the third complementary pixel group, the pixel 802 corresponding to the ejection defective nozzle is included only in the mask pattern 605 corresponding to the scanning of the first time. Therefore, in step S703, the code value “11” of the pixel 802 in the mask pattern 605 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “11” of the pixel 802 in the mask pattern 605 corresponding to the scanning of the first time is selected as the code value A.
Further, in the third complementary pixel group, the pixel 802 corresponding to the ejection normal nozzle is included in the mask patterns 606 and 607 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “10” of the pixel 802 in the mask pattern 606 corresponding to the scanning of the second time, and the code value “01” of the pixel 802 in the mask pattern 607 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “01” of the pixel 802 in the mask pattern 607 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink in the two code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (three times) indicated by the code value “11” of the pixel 802 in the mask pattern 605 as the code value A is larger than the number of times of permission (once) indicated by the code value “01” of the pixel 802 in the mask pattern 607 as the code value B. Therefore, as illustrated in
As described above, in the third complementary pixel group, since there is only one complementary source candidate pixel, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the third complementary pixel group by the above-described processing in step S709. Then, in step S710, since the non-ejection complementary processing has not yet been executed in the remaining fourth complementary pixel group, the processing returns to step S704.
Next, a case in which the fourth complementary pixel group made of three pixels 803 in the mask patterns 605 to 607 is selected in step 704 will be described.
In the fourth complementary pixel group, the pixel 803 corresponding to the ejection defective nozzle is included only in the mask pattern 605 corresponding to the scanning of the first time. Therefore, in step S703, the code value “01” of the pixel 803 in the mask pattern 605 corresponding to the scanning of the first time is acquired as the code value of the complementary source candidate pixel. Since there is only one complementary source candidate pixel, in step S704, the code value “01” of the pixel 803 in the mask pattern 605 corresponding to the scanning of the first time is selected as the code value A.
Further, in the fourth complementary pixel group, the pixel 803 corresponding to the ejection normal nozzle is included in the mask patterns 606 and 607 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “11” of the pixel 803 in the mask pattern 606 corresponding to the scanning of the second time, and the code value “10” of the pixel 803 in the mask pattern 607 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “10” of the pixel 803 in the mask pattern 607 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink in the two code values, is selected as the code value B.
Then, in step S707, it is determined that the number of times of permission (once) indicated by the code value “01” of the pixel 803 in the mask pattern 605 as the code value A is smaller than the number of times of permission (twice) indicated by the code value “10” of the pixel 803 in the mask pattern 607 as the code value B. Therefore, the replacement processing in step S708 is not executed. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the fourth complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the fourth complementary pixel group by the above-described processing in step S709. Then, it is determined that the non-ejection complementary processing has been executed in all the complementary pixel groups in step S710, and the non-ejection complementary processing is terminated.
As can be seen from
By use of the mask patterns after the non-ejection complementary processing in the present embodiment is executed, when compared with the print data illustrated in
Therefore, the logical sum (
Here, while the ejection (“1”) of ink is determined in the pixels 800, 801, and 802 in the print data corresponding to the scanning of the first time illustrated in
As described above, while the number of times of ejection is supposed to be the number of times of ejection as illustrated in
Here, the first line of
In the four-pass printing method, when the code value of the complementary source pixel is “00”, the code values allocated to the pixels corresponding to the ejection normal nozzle in the mask patterns before the non-ejection complementary processing are “01”, “10”, and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed even if the pixel value of the image data is any of “00”, “01”, “10”, and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “01”, “10”, and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is any of “00”, “01”, “10”, and “11”.
In the four-pass printing method, when the code value of the complementary source pixel is “01”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00”, “10”, and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed where the pixel values of the image data are “00”, “01”, and “10”. However, when the pixel value of the image data is “11”, an ideal number of times of ejection of ink cannot be expressed. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “01”, “10”, and “11”. Therefore, when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is any of “00”, “01”, “10”, and “11”.
In the four-pass printing method, when the code value of the complementary source pixel is “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00”, “01”, and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed where the pixel values of the image data are “00” and “01”. However, ideal numbers of times of ejection of ink cannot be expressed where the pixel values of the image data are “10” and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “01”, “10”, and “11”. Therefore, when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is any of the “00”, “01”, “10”, and “11”.
In the four-pass printing method, when the code value of the complementary source pixel is “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00”, “01”, and “10”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is “00”. However, when the pixel values of the image data are “01”, “10”, and “11”, ideal numbers of times of ejection of ink cannot be expressed. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “01”, “10”, and “11”. Therefore, when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is any of “00”, “01”, “10”, and “11”.
In the three-pass printing method, when the code value of the complementary source pixel is “01”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “10” and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection can be expressed where the pixel values of the image data are “00”, “01”, and “10” although an ideal number of times of ejection of ink cannot be expressed where the pixel value of the image data is “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed where the pixel values of the image data are “00”, “01”, and “10” although an ideal number of times of ejection of ink cannot be expressed where the pixel value of the image data is “11”.
In the three-pass printing method, when the code value of the complementary source pixel is “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed where the pixel values of the image data are “00” and “01”. However, ideal numbers of times of ejection of ink cannot be expressed where the pixel values of the image data are “10” and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed where the pixel values of the image data are “00” and “01”. However, an ideal number of times of ejection of ink cannot be expressed where the pixel value of the image data is “11”. Note that an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is “10”, compared with the case before the non-ejection complementary processing.
In the three-pass printing method, when the code value of the complementary source pixel is “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “10”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is “00”. However, ideal numbers of times of ejection of ink cannot be expressed where the pixel values of the image data are “01”, “10”, and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink cannot be expressed where the pixel value of the image data is “11” while an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is “00”. Note that an ideal number of times of ejection of ink can be expressed where the pixel values of the image data are “01” and “10”, compared with the case before the non-ejection complementary processing.
Comparative ExampleNext, differences of a comparative example from the present embodiment in a case where non-ejection complementary processing according to the comparative example is executed when an ejection defective nozzle that can eject an ink to a certain pixel region occurs will be described below in detail. In the comparative example, the non-ejection complementary processing is performed by finding a pixel with a code value of “00” in a mask pattern corresponding to an ejection normal nozzle that can eject an ink to the pixel region corresponding to the ejection defective nozzle in the different scanning, and replacing a code value of a pixel corresponding to the pixel region in a mask pattern corresponding to the ejection defective nozzle with the code value “00” of the pixel corresponding to the pixel region in the mask pattern corresponding to the ejection normal nozzle. Note that, as mask patterns before the non-ejection complementary processing, mask patterns similar to those before the non-ejection complementary processing described in the first embodiment are used.
According to the comparative example, for example, when the code value of the complementary source pixel is “11” in a three-pass printing method, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “10”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed where the pixel value of the image data is “00”. However, an ideal number of times ejection of ink cannot be expressed where the pixel values of the image data are “01”, “10”, and “11”.
Here, even if the non-ejection complementary processing is performed, no code value of “00” is allocated to the pixels corresponding to the ejection normal nozzles. Therefore, according to the comparative example, the code value of the complementary destination pixel cannot be acquired. Accordingly, even if the non-ejection complementary processing is performed, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns remain in “01” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, ideal number of times of ejection of ink cannot be expressed where the pixel values of the image data are “01”, “10”, and “11”.
As describe above, it can be seen that, in the present embodiment, the non-ejection complementary processing with less degradation of image quality is executable than the comparative example.
As described above, by executing the non-ejection complementary processing according to the present embodiment, favorable complement printing can be performed when ejection failure of an ejection port is caused even if the image data and the mask pattern having multiple-bit information are used.
Second EmbodimentIn the first embodiment, a form in which the favorable non-ejection complementary processing is executed when the ejection defective nozzle corresponds to only one pixel in the plurality of mask patterns (there is one complementary source candidate pixel) has been described.
In contrast, in the present embodiment, a form in which favorable non-ejection complementary processing is executed even when ejection defective nozzles correspond to a plurality of pixels in a plurality of mask patterns (there is a plurality of complementary source candidate pixels) will be described.
Note that description of similar portions to the first embodiment described above is omitted.
Degradation of image quality of when ejection failure of ink occurs in a plurality of ejection ports when using image data and mask patterns having multiple-bit information will be described in detail.
As illustrated in
When the image data and the mask patterns illustrated in
Similarly, as can be seen from
Accordingly, the ink is ejected to the pixel region corresponding to the pixel 700 in the unit area 211 twice in total, while an ideal number of times of ejection of ink is three times, as illustrated in
In view of the foregoing, in the present embodiment, processing in step S704 in the non-ejection complementary processing illustrated in
In step S704 in the non-ejection complementary processing illustrated in
In contrast, the present embodiment, when a plurality of code values has been acquired as code values of complementary source candidate pixels in step S703, a code value indicating a largest number of times of permission of ejection of ink is selected. Then, when the processing of step S703 is executed again through steps S705 to S709, a code value indicating the next largest number of times of permission of ejection of ink to the previously selected code value is selected. In this way, in the present embodiment, when a plurality of complementary source candidate pixels exists, replacement processing is executed in order from the pixel to which the code value having a larger number of times of permission of ejection of ink is allocated.
A process of when the non-ejection complementary processing in the present embodiment is executed in the four-pass printing method will be described in detail, using the case where the ejection defective nozzles 30a and 30d occur, as illustrated in
Here, when the ejection defective nozzles 30a and 30d illustrated in
In the first complementary pixel group, the pixels 700 corresponding to the ejection defective nozzles are included in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times. Therefore, two code values including the code value “11” of the pixel 700 in the mask pattern 505 corresponding to the scanning of the first time and the code value “00” of the pixel 700 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary source candidate pixels in step S703.
In step S704, the code value “11” of the pixel 700 in the mask pattern 505 corresponding to the scanning of the first time, which has a larger number of times of permission of ejection of ink, of the two code values “11” and “01” acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in the first complementary pixel group, the pixels 700 corresponding to the ejection normal nozzles are included in mask patterns 506 and 507 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “10” of the pixel 700 in the mask pattern 506 corresponding to the scanning of the second time, and the code value “01” of the pixel 700 in the mask pattern 507 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “01” of the pixel 700 in the mask pattern 507 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink, of the two code values, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (three times) indicated by the code value “11” of the pixel 700 in the mask pattern 505 as the code value A is larger than the number of times of permission (once) indicated by the code value “01” of the pixel 700 in the mask pattern 507 as the code value B. Therefore, as illustrated in
In this stage, the non-ejection complementary processing has not yet been executed in the pixel 700 in the mask pattern 508 corresponding to the scanning of the fourth time, of the complementary source candidate pixels. Therefore, in step S709, the processing returns to step S704.
Then, in step S704, the code value “00” of the pixel 700 in the mask pattern 508 corresponding to the scanning of the fourth time, which is the complementary source candidate pixel for which the non-ejection complementary processing has not yet been performed, of the code values “11” and “00” of the pixels 700 in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times and acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in step S706, the code value “10” of the pixel 700 in the mask pattern 506 corresponding to the scanning of the second time, which is the complementary destination candidate pixel for which the replacement in step S708 has not yet been executed, of the code values “10” and “01” of the pixels 700 in the mask patterns 506 and 507 corresponding to the scanning of the second and third times and acquired in step S705, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (zero times) indicated by the code value “00” of the pixel 700 in the mask pattern 508 as the code value A is smaller than the number of times of permission (twice) indicated by the code value “10” of the pixel 700 in the mask pattern 506 as the code value B. Therefore, replacement processing in step S708 is not executed. Therefore, as illustrated in
Following that, in step S709, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the first complementary pixel group by the above-described processing. Then, since the non-ejection complementary processing has not yet been executed in the remaining second, third, and fourth complementary pixel groups, in step S701, the processing returns to step S704.
Next, a case in which the second complementary pixel group made of four pixels 701 in the mask patterns 505 to 508 is selected from the remaining second, third, and fourth complementary pixel groups in step 704 will be described.
In the second complementary pixel group, the pixels 701 corresponding to the ejection defective nozzles are included in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times. Therefore, in step S703, two code values including the code value “10” of the pixel 701 in the mask pattern 505 corresponding to the scanning of the first time, and the code value “11” of the pixel 701 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary source candidate pixels.
In step S704, the code value “11” of the pixel 701 in the mask pattern 508 corresponding to the scanning of the fourth time, which has a larger number of times of permission of ejection of ink, of the two code values “10” and “11” acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in the second complementary pixel group, the pixels 701 corresponding to the ejection normal nozzles are included in the mask patterns 506 and 507 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “01” of the pixel 701 in the mask pattern 506 corresponding to the scanning of the second time, and the code value “00” of the pixel 701 in the mask pattern 507 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “00” of the pixel 701 in the mask pattern 507 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink, of the two code values, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (three times) indicated by the code value “11” of the pixel 701 in the mask pattern 508 as the code value A is larger than the number of times of permission (zero times) indicated by the code value “00” of the pixel 701 in the mask pattern 507 as the code value B. Therefore, as illustrated in
In this stage, the non-ejection complementary processing has not yet been executed in the pixel 701 in the mask pattern 505 corresponding to the scanning of the first time, of the complementary source candidate pixels. Therefore, in step S709, the processing returns to step S704.
Then, in step S704, the code value “10” of the pixel 701 in the mask pattern 505 corresponding to the scanning of the first time, which is the complementary source candidate pixel for which the non-ejection complementary processing has not yet been performed, of the code values “10” and “11” of the pixels 701 in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times and acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in step S706, the code value “01” of the pixel 701 in the mask pattern 506 corresponding to the scanning of the second time, which is the complementary destination candidate pixel for which replacement in step S708 has not yet been executed, of the code values “01” and “00” of the pixels 701 in the mask patterns 506 and 507 corresponding to the scanning of the second and third times and acquired in step S705, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (twice) indicated by the code value “10” of the pixel 701 in the mask pattern 505 as the code value A is larger than the number of times of permission (once) indicated by the code value “01” of the pixel 701 in the mask pattern 506 as the code value B. Therefore, as illustrated in
Following that, in step S709, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the second complementary pixel group by the above-described processing. Then, since the non-ejection complementary processing has not yet been executed in the remaining third and fourth complementary pixel groups, in step S710, the processing returns to step S704.
Next, a case in which the third complementary pixel group made of four pixels 702 in the mask patterns 505 to 508 is selected from the remaining third and fourth complementary pixel groups in step 704 will be described.
In the third complementary pixel group, the pixels 702 corresponding to the ejection defective nozzles are included in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times. Therefore, in step S703, two code values including the code value “01” of the pixel 702 in the mask pattern 505 corresponding to the scanning of the first time, and the code value “10” of the pixel 702 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary source candidate pixels.
In step S704, the code value “10” of the pixel 702 in the mask pattern 508 corresponding to the scanning of the fourth time, which has a larger number of times of permission of ejection of ink, of the two code values “01” and “10” acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in the third complementary pixel group, the pixels 702 corresponding to the ejection normal nozzles are included in the mask patterns 506 and 507 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “00” of the pixel 702 in the mask pattern 506 corresponding to the scanning of the second time, and the code value “11” of the pixel 702 in the mask pattern 507 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixels. In step S706, the code value “00” of the pixel 702 in the mask pattern 506 corresponding to the scanning of the second time, which indicates the smallest number of times of permission of ejection of ink, of the two code values, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (twice) indicated by the code value “10” of the pixel 702 in the mask pattern 508 as the code value A is larger than the number of times of permission (zero times) indicated by the code value “00” of the pixel 702 in the mask pattern 506 as the code value B. Therefore, as illustrated in
In this stage, the non-ejection complementary processing has not yet been executed in the pixel 702 in the mask pattern 505 corresponding to the scanning of the first time, of the complementary source candidate pixels. Therefore, in step S709, the processing returns to step S704.
Then, in step S704, the code value “01” of the pixel 702 in the mask pattern 505 corresponding to the scanning of the first time, which is the complementary source candidate pixel for which the non-ejection complementary processing has not yet been performed, of the code values “01” and “10” of the pixels 702 in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times and acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in step S706, the code value “11” of the pixel 702 in the mask pattern 507 corresponding to the scanning of the third time, which is the complementary destination candidate pixel for which replacement in step S708 has not yet been executed, of the code values “00” and “11” of the pixels 702 in the mask patterns 506 and 507 corresponding to the scanning of the second and third times and acquired in step S705, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (once) indicated by the code value “01” of the pixel 702 in the mask pattern 505 as the code value A is smaller than the number of times of permission (three times) indicated by the code value “11” of the pixel 702 in the mask pattern 507 as the code value B. Therefore, the replacement processing in step S708 is not executed. Therefore, as illustrated in
Following that, in step S709, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the third complementary pixel group by the above-described processing. Then, since the non-ejection complementary processing has not yet been performed in the remaining fourth complementary pixel group, in step S710, the processing returns to step S704.
Next, a case in which the fourth complementary pixel group made of four pixels 703 in the mask patterns 505 and 508 is selected in step 704.
In the fourth complementary pixel group, the pixels 703 corresponding to the ejection defective nozzles are included in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times. Therefore, in step S703, two code values including the code value “00” of the pixel 703 in the mask pattern 505 corresponding to the scanning of the first time, and the code value “01” of the pixel 703 in the mask pattern 508 corresponding to the scanning of the fourth time are acquired as the code values of the complementary source candidate pixels.
In step S704, the code value “01” of the pixel 703 in the mask pattern 508 corresponding to the scanning of the fourth time, which has a larger number of times of permission of ejection of ink, of the two code values “00” and “01” and acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in the third complementary pixel group, the pixels 703 corresponding to the ejection normal nozzles are included in the mask patterns 506 and 507 corresponding to the scanning of the second and third times. Therefore, in step S705, two code values including the code value “11” of the pixel 703 in the mask pattern 506 corresponding to the scanning of the second time, and the code value “10” of the pixel 703 in the mask pattern 507 corresponding to the scanning of the third time are acquired as the code values of the complementary destination candidate pixel. In step S706, the code value “01” of the pixel 703 in the mask pattern 507 corresponding to the scanning of the third time, which indicates the smallest number of times of permission of ejection of ink, of the two code values, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (once) indicated by the code value “01” of the pixel 703 in the mask pattern 508 as the code value A is smaller than the number of times of permission (twice) indicated by the code value “10” of the pixel 703 in the mask pattern 507 as the code value B. Therefore, the replacement processing in step S708 is not executed. Therefore, as illustrated in
In this stage, the non-ejection complementary processing has not yet been executed in the pixel 703 in the mask pattern 505 corresponding to the scanning of the first time, of the complementary source candidate pixels. Therefore, in step S709, the processing returns to step S704.
Then, in step S704, the code value “00” of the pixel 703 in the mask pattern 505 corresponding to the scanning of the first time, which is the complementary source candidate pixel for which the non-ejection complementary processing has not yet been performed, of the code values “00” and “01” of the pixels 703 in the mask patterns 505 and 508 corresponding to the scanning of the first and fourth times and acquired in step S703, is selected as the code value A of the complementary source pixel.
Further, in step S706, the code value “11” of the pixel 703 in the mask pattern 506 corresponding to the scanning of the second time, which is the complementary destination candidate pixel for which replacement in step S708 has not yet been executed, of the code values “11” and “10” of the pixels 703 in the mask patterns 506 and 507 corresponding to the scanning of the second and third times and acquired in step S705, is selected as the code value B of the complementary destination pixel.
Then, in step S707, it is determined that the number of times of permission (zero times) indicated by the code value “00” of the pixel 703 in the mask pattern 505 as the code value A is smaller than the number of times of permission (three times) indicated by the code value “11” of the pixel 703 in the mask pattern 506 as the code value B. Therefore, the replacement processing in step S708 is not executed. Therefore, as illustrated in
As described above, since there is only one complementary source candidate pixel in the fourth complementary pixel group, it is determined that the non-ejection complementary processing has been performed for all the complementary source candidate pixels in the fourth complementary pixel group by the above-described processing in step S709. Then, in step S710, it is determined that the non-ejection complementary processing has been executed in all the complementary pixel groups, and the non-ejection complementary processing is terminated.
As can be seen from
By use of the mask patterns after the non-ejection complementary processing in the present embodiment is executed, when compared with the print data illustrated in
Therefore, as illustrated in
Here, while the ejection (“1”) of ink is determined in the pixels 700 and 701 in the print data corresponding to the scanning of the first time illustrated in
Therefore, when the ink is ejected according to the print data illustrated in
As described above, by performing the non-ejection complementary processing according to the present embodiment, the degradation of the image quality as illustrated in
Here, the first line of
When the code values of the complementary source candidate pixels are “00” and “01”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “10” and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “00”, “01”, and “10”, although an ideal number of times of ejection cannot be expressed when the pixel value of the image data is “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”. Therefore, when the mask patterns after the non-ejection complementary processing are used, similarly to the case of using the mask patterns before the non-ejection complementary processing, ideal numbers of times of ejection can be expressed when the pixel values of the image data are “00”, “01”, and “10”, although an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “11”.
When the code values of the complementary source candidate pixels are “00” and “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “00” and “01”. However, ideal numbers of times of ejection of ink cannot be expressed when the pixel values of the image data are “10” and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “11”, although ideal numbers of times of ejection of ink can be expressed when the pixel values of image data are “00” and “01”. Note that, when the pixel value of the image data is “10”, compared with the case before the non-ejection complementary processing, an ideal number of times of ejection of ink can be expressed.
When the code values of the complementary source candidate pixels are “00” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “10”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection can be expressed when the pixel value of the image data is “00”. However, ideal numbers of times of ejection cannot be expressed when the pixel values of the image data are “01”, “10”, and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “11”, although an ideal number of times of ejection can be expressed when the pixel value of the image data is “00”. Note that ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “01” and “10”, compared with the case before the non-ejection complementary processing.
When the code values of the complementary source candidate pixels are “01” and “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection can be expressed when the pixel values of the image data are “00” and “01”. However, an ideal number of times of ejection cannot be expressed when the pixel value of the image data is “10”. Further, when the pixel value of the image data is “11”, the number of times of ejection is largely shifted from an ideal number of times of ejection of ink. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even if the mask patterns after the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “00” and “01”. Further, an ideal number of times of ejection can be expressed even when the pixel value of the image data is “10”. Further, the gap between the number of times of ejection of ink expressed when the pixel value of the image data is “11” and an ideal number of times of ejection of ink can be made smaller than that before the non-ejection complementary processing.
When the code values of the complementary source candidate pixels are “01” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “10”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00”. However, ideal numbers of times of ejection of ink cannot be expressed when the pixel values of the image data are “01” and “10”. Further, the number of times of ejection is largely shifted from an ideal number of times of ejection of ink when the pixel value of the image data is “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00”. Further, ideal numbers of times of ejection can be expressed even when the pixel values of the image data are “01” and “10”. Further, the gap between the number of times of ejection of ink expressed when the pixel value of the image data is “11” and an ideal number of times of ejection of ink can be made smaller than that before the non-ejection complementary processing.
When the code values of the complementary source candidate pixels are “10” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “01”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00”. However, an ideal number of times of ejection cannot be expressed when the pixel value of the image data is “01”. Further, the number of times of ejection is largely shifted from ideal numbers of times of ejection of ink when the pixel values of the image data are “10” and “11”. Meanwhile, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”. Therefore, even when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00”. Further, an ideal number of times of ejection of ink can be expressed even when the pixel values of the image data are “01” and “10”. Further, the gap between the number of times of ejection of ink expressed when the pixel value of the image data is “11” and an ideal number of times of ejection of ink can be made smaller than that before the non-ejection complementary processing.
Comparative ExampleNext, differences of a comparative example from the second embodiment will be described in detail, where a form of selecting the complementary source pixel in order from the pixel to which the code value with a smaller number of times of permission of ejection of ink is allocated in step S704, when a plurality of complementary source candidate pixels exists, is used as the comparative example.
According to the comparative example, for example, when the code values of the complementary source candidate pixels are “00” and “10”, in the processing in step S704 of the first time, the code value “00” with a small number of times of permission of ejection of ink is selected as the code value A of the complementary source pixel. Then, in the processing in step S706 of the first time, the code value “01” with a smaller number of times of permission of ejection of ink, of the code values “01” and “11” of the complementary destination candidate pixels, is selected as the code value B of the complementary destination pixel. Therefore, in the non-ejection complementary processing of the first time, the code value B of the complementary destination pixel is not replaced in step S708.
Next, the code value “10” of the remaining complementary source candidate pixel is selected as the code value A of the complementary source pixel in the processing in step S704 of the second time. Then, the code value “11” of the remaining complementary destination candidate pixel is selected as the code value B of the complementary destination pixel in the processing in step S706 of the second time. Therefore, the code value B of the complementary destination pixel is not replaced in the step S708 of the non-ejection complementary processing of the second time.
Therefore, according to the non-ejection complementary processing of the comparative example, when the code values of the complementary source candidate pixels are “00” and “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles are “01” and “11”.
Similarly, in any case of when the code values of the complementary source candidate pixels are “00” and “11”, when the code values are “01” and “10”, and when the code values are “01” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles are “01” and “11” according to the non-ejection complementary processing of the comparative example.
As can be seen from
Meanwhile, as illustrated in
As described above, in the second embodiment, it can be seen that the non-ejection complementary processing with less degradation of the image quality than the comparative example is executable.
As described above, by executing the non-ejection complementary processing according to the second embodiment, favorable complement printing can be performed even in a case where the ejection failure is caused in a plurality of ejection ports when the image data and the mask patterns having multiple-bit information are used.
Third EmbodimentIn the second embodiment, a form of performing the favorable non-ejection complementary processing even when the ejection defective nozzles correspond to a plurality of pixels, by selecting the complementary source pixel in order from the pixel to which the code value with a larger number of times of permission of ejection of ink is allocated in step S704, in a case where a plurality of complementary source candidate pixels exists, has been described.
In contrast, in the present embodiment, a form of performing favorable non-ejection complementary processing even when ejection defective nozzles correspond to a plurality of pixels by another method will be described.
Note that description of similar portions to the above-described first and second embodiments is omitted.
In the present embodiment, when a plurality of code values has been acquired as code values of complementary source candidate pixels corresponding to ejection defective nozzles in step S703, one code value is randomly selected from the plurality of code values, as a code value A of a complementary source pixel, in step S704. Meanwhile, in the present embodiment, even if replacement has been executed for a complementary destination pixel once in step S708 in one complementary pixel group, the complementary destination pixel is not excluded from complementary destination candidate pixels in step S705 in subsequent processing and is used as a complementary candidate pixel again after the replacement.
Here, the first line of
When the code values of the complementary source candidate pixels are “00” and “01”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “10” and “11”. Here, a case where the code value “00” is selected and a case where the code value “01” is selected as the code value A of the complementary source pixel in step S704 of the first time in the present embodiment will be respectively described.
(i) A Case where the Code Value “00” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “10” having a small number of times of permission of ejection of ink of the two code values “10” and “11” is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, replacement in step S708 is not performed.
Next, the remaining code value “01” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “10” that has been selected in step S706 of the first time but for which the replacement has not been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, in step S706 of the second time, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “11” and “10”, is selected as the code value B of the complementary source pixel.
Since the number of times of permission indicated by the code value “01” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “01” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “10” having a smaller number of times of permission of ejection of ink of the code values “10” and “11” is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “01” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed.
Next, in step S705 of the second time, the remaining code value “00” is selected as the code value A of the complementary source pixel. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “10” that has been selected in step S706 of the first time, but for which the replacement has not been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “11” and “10”, is selected as the code value B of the complementary source pixel in step S706 of the second time.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
Further, when the code values of the complementary source candidate pixel are “00” and “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “11”. Here, a case where the code value “00” is selected and a case where the code value “10” is selected as the code value A of the complementary source pixel in step S704 of the first time in the present embodiment will be respectively described.
(i) A Case where the Code Value “00” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “11”, is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the replacement in step S708 is not performed.
Next, the remaining code value “10” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “01” that has been selected in step S706 of the first time, but for which the replacement has not been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “11” and “01”, is selected as the code value B of the complementary source pixel in step S706.
The number of times of permission indicated by the code value “10” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “10” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “10” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “11”, is selected as the code value B of the complementary destination pixel. The number of times of permission indicated by the code value “10” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “10” in step S708.
Next, the remaining code value “00” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “10” for which the replacement has been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “11” and “10”, is selected as the code value B of the complementary source pixel in step S706.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
Further, when the code values of the complementary source candidate pixels are “00” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “01” and “10”. Here, a case where the code value “00” is selected and a case where the code value “11” is selected as the code value A of the complementary source pixel in step S704 of the first time in the present embodiment will be respectively described.
(i) A Case where the Code Value “00” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “10”, is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the replacement in step S708 is not performed.
Next, the remaining code value “11” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “10” that has not been selected in step S706 of the first time, and the code value “01” that has been selected in step S706 of the first time, but for which the replacement has not been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, in step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “10” and “01”, is selected as the code value B of the complementary source pixel.
The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “11” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “11” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “10”, is selected as the code value B of the complementary destination pixel. The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “11” in step S708.
Next, the remaining code value “00” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “10” that has not been selected in step S706 of the first time, and the code value “11” after the replacement has been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, in step S706, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “10” and “11”, is selected as the code value B of the complementary source pixel.
The number of times of permission indicated by the code value “00” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
Further, when the code values of the complementary source candidate pixels are “01” and “10”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “11”. Here, a case where the code value “01” is selected and a case where the code value “10” is selected as the code value A of the complementary source pixel in step S704 of the first time in the present embodiment will be respectively described.
(i) A Case where the Code Value “01” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “00” having a smaller number of times of permission of ejection of ink, of the code values “00” and “11”, is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “01” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “01” in step S708.
Next, in step S705 of the second time, the remaining code value “10” is selected as the code value A of the complementary source pixel. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “01” after the replacement has been performed in step S708 of the first time are acquired as the code values of the complementary destination candidate pixels. Then, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “11” and “01”, is selected as the code value B of the complementary source pixel in step S706.
The number of times of permission indicated by the code value “10” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “10” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “10” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “00” and “11”, is selected as the code value B of the complementary destination pixel. The number of times of permission indicated by the code value “10” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “10” in step S708.
Next, the remaining code value “01” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “11” that has not been selected in step S706 of the first time, and the code value “10” for which the replacement has been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “11” and “10”, is selected as the code value B of the complementary source pixel in step S706.
The number of times of permission indicated by the code value “01” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
Further, when the code values of the complementary source candidate pixels are “01” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “10”. Here, a case where the code value “01” is selected and a case where the code value “11” is selected as the code value A of the complementary source pixel in step S704 of the first time of the present embodiment will be respectively described.
(i) A Case where the Code Value “01” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “00” having a smaller number of times of permission of ejection of ink, of the code values “00” and “10”, is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “01” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “01” in step S708.
Next, the remaining code value “11” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “10” that has not been selected in step S706 of the first time, and the code value “01” after the replacement has been performed in step S708 of the first time are acquired as the code values of the complementary destination candidate pixels. Then, in step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “10” and “01”, is selected as the code value B of the complementary source pixel.
The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “11” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “11” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “00” having a smaller number of times of permission of ejection of ink, of the code values “00” and “10”, is selected as the code value B of the complementary destination pixel. The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “11” in step S708.
Next, the remaining code value “01” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “10” that has not been selected in step S706 of the first time, and the code value “11” after the replacement has been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, the code value “10” having a smaller number of times of permission of ejection of ink, of the code values “11” and “10”, is selected as the code value B of the complementary source pixel in step S706.
The number of times of permission indicated by the code value “01” as the code value A is smaller than the number of times of permission indicated by the code value “10” as the code value B. Therefore, the replacement in step S708 is not performed. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
Further, when the code values of the complementary source candidate pixels are “10” and “11”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00” and “01”. Here, a case where the code value “10” is selected and a case where the code value “11” is selected as the code value A of the complementary source pixel in step S704 of the first time in the present embodiment will be respectively described.
(i) A Case where the Code Value “10” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “00” having a smaller number of times of permission of ejection of ink, of the code values “00” and “01”, is selected as the code value B of the complementary destination pixel.
The number of times of permission indicated by the code value “10” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “10” in step S708.
Next, the remaining code value “11” is selected as the code value A of the complementary source pixel in step S705 of the second time. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “01” that has not been selected in step S706 of the first time, and the code value “10” for which the replacement has been performed in step S708 of the first time are acquired as the code values of the complementary destination candidate pixels. Then, in step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “10”, is selected as the code value B of the complementary source pixel.
The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “01” as the code value B. Therefore, the code value “01” is replaced with the code value “11” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are “10” and “11”.
(ii) A Case where the Code Value “11” is Selected as the Code Value A of the Complementary Source Pixel in Step S704 of the First Time
In step S706, the code value “00” having a smaller number of times of permission of ejection of ink, of the code values “00” and “01”, is selected as the code value B of the complementary destination pixel. The number of times of permission indicated by the code value “11” as the code value A is larger than the number of times of permission indicated by the code value “00” as the code value B. Therefore, the code value “00” is replaced with the code value “11” in step S708.
Next, in step S705 of the second time, the remaining code value “10” is selected as the code value A of the complementary source pixel. Here, in the present embodiment, a pixel once selected as the complementary destination pixel serves as the complementary destination candidate pixel in the subsequent processing regardless of whether the replacement has been performed. Therefore, in step S705 of the second time, the code value “01” that has not been selected in step S706 of the first time, and the code value “11” after the replacement has been performed in step S708 are acquired as the code values of the complementary destination candidate pixels. Then, in step S706, the code value “01” having a smaller number of times of permission of ejection of ink, of the code values “01” and “11”, is selected as the code value B of the complementary source pixel.
The number of times of permission indicated by the code value “01” as the code value A is larger than the number of ties of permission indicated by the code value “10” as the code value B. Therefore, the code value “01” is replaced with the code value “10” in step S708. Therefore, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns after the non-ejection complementary processing are also “10” and “11”.
As described above, according to the present embodiment, when the ejection failure of ink has occurred in a plurality of ejection ports, the code values allocated to the ejection normal nozzles in the mask pattern after the non-ejection complementary processing can be made to “10” and “11”, similarly to the second embodiment illustrated in
In the above-described first to third embodiments, forms to replace the code value B using the code value A when the code value A of the complementary source pixel is larger than the code value B of the complementary destination have been described.
In contrast, in the present embodiment, a form to exchange a code value A and a code value B when the code value A of a complementary source pixel is larger than the code value B of the complementary destination will be described.
Note that description of similar portions to the first to third embodiments is omitted.
A small amount of ink may be ejected when ejection of ink is determined in print data even in a case of an ejection defective nozzle.
That is, an ejection port corresponding to a region where a decrease in density is shown may also be identified as the ejection detective nozzle, in addition to an ejection port corresponding to a region where no ink is ejected, when a test pattern is printed and the test pattern is read. In this case, a small amount of ink may be ejected through the ejection defective nozzle corresponding to the region where the decrease in density is shown. Therefore, as described in the first to third embodiments, a small amount of ink may be ejected through the ejection defective nozzle if the print data that indicates ejection of ink remains allocated to the ejection defective nozzle. In this case, even if an ideal number of times of ejection of ink is expressed even when ejection failure occurs by the non-ejection complementary processing described in the first to third embodiments, a gap may be caused from the ideal number of times of ejection due to ejection of a small amount of ink through the ejection defective nozzle.
In view of the foregoing, in the present embodiment, non-ejection complementary processing such as print data that indicates non-ejection (“0”) of ink being able to be easily generated for a pixel corresponding to the ejection defective nozzle is performed.
In step S807, when it is determined that the number of times of permission indicated by the code value A selected in step S804 is larger than the number of times of permission indicated by the code value B selected in step S806, in step S808, processing of exchanging the code value B determined for the complementary destination pixel and the code value A determined for the complementary source pixel is performed. Meanwhile, when the number of times of permission indicated by the code value A is smaller than the number of times of permission indicated by the code value B, the exchange processing is not executed.
For example, when the code value A selected in step S804 is “11”, and the code value B selected in step S806 is “00”, the number of times of permission (three times) indicated by the code value A is larger than the number of times of permission (zero times) indicated by the code value B. Therefore, in step S808, the code value B “00” of the complementary destination pixel and the code value A “11” of the complementary source pixel are exchanged. Therefore, after the exchange processing, the code value “11” is allocated to the complementary destination pixel, and the code value “00” is allocated to the complementary source pixel.
A process of when the non-ejection complementary processing illustrated in
Note that description of portions similar to the execution process of the non-ejection complementary processing illustrated in
In the execution process of the non-ejection complementary processing illustrated in
Meanwhile, in the present embodiment, the code value “00” of the pixel 700 in the mask pattern 508 and the code value “11” of the pixel 700 in the mask pattern 505 are exchanged in step S808. Therefore, as illustrated in
Accordingly, the code value having a smaller number of times of permission is allocated to the pixel corresponding to the ejection defective nozzle in the mask pattern after the non-ejection complement. For example, by performing the non-ejection complementary processing of the present embodiment for the mask patterns illustrated in
As described above, according to the present embodiment, printing in which a gap from an ideal number of times of ejection due to ejection of a small amount of ink through the ejection defective nozzle is suppressed can be performed.
Fifth EmbodimentIn the present embodiment, the processing illustrated in
Note that description of similar portions to the first to fourth embodiments is omitted.
Steps S901 and S902 are similar to steps S701 and S702 illustrated in
Next, in step S903, one code value of code values of complementary source candidate pixels corresponding to ejection defective nozzles, of a complementary pixel group selected in step S902, is acquired as a code value A of a complementary source pixel. When a plurality of code values of complementary source candidate pixels exists, one code value may be randomly selected and acquired, or a code value having a larger number of times of permission of ejection of ink may be selected and acquired.
Next, in step S904, whether a code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels corresponding to ejection normal nozzles, and indicating a smaller number of times of permission than the code value A of the complementary source pixel acquired in step S903 exists is determined.
For example, when the code value A of the complementary source pixel acquired in step S903 is “11”, and the code values of the complementary destination candidate pixels are “00”, “01”, and “10”, the code value “00” of the code values of the complementary destination candidate pixels satisfies the above conditions. Therefore, it is determined that the code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels, and indicating a smaller number of times of permission than the code value A of the complementary source pixel exists.
Further, for example, when the code value A of the complementary source pixel acquired in step S903 is “10”, and the code values of the complementary destination candidate pixels are “01” and “11”, the code value “01” of the code values of the complementary destination candidate pixel satisfies the above conditions. Therefore, it is determined that the code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels, and indicating a smaller number of times of permission than the code value A of the complementary source pixel exists.
Further, for example, when the code value A of the complementary source pixel acquired in step S903 is “01”, and the code values of the complementary destination candidate pixels are “10” and “11”, any of the code values of the complementary destination candidate pixel does not satisfy the above conditions. Therefore, it is determined that the code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels, and indicating a smaller number of times of permission than the code value A of the complementary source pixel does not exist.
In step S904, when it is determined that the code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels, and indicating a smaller number of times of permission than the code value A of the complementary source pixel exists, in step S905, the code value is acquired as the code value B of the complementary destination pixel. Then, in step S906, processing of replacing the code value B of the complementary destination pixel acquired in step S905 with the code value A of the complementary source pixel acquired in step S903 is performed.
Following that, in step S907, whether the complementary source candidate pixel for which the processing in steps S903 to S906 has not yet been executed, of the complementary pixel group selected in step S902, exists is determined. When it is determined that the processing in steps S903 to S906 has been executed for all the complementary source candidate pixels, the processing proceeds to step S908. Meanwhile, when it is determined that a remaining complementary source candidate pixel for which the processing in steps S903 to S906 has not yet been executed exists, the processing returns to step S903, and processing similar to the processing in step S903 to S906 is executed for the remaining complementary source candidate pixel. Here, the complementary destination pixel for which replacement has been executed even once in step S906 in one complementary pixel group may be excluded from the complementary destination candidate pixels in step S904 or may be used as the complementary candidate pixel again in the subsequent processing.
Meanwhile, in step S904, when it is determined that the code value indicating a smallest number of times of permission in code values of complementary destination candidate pixels, and indicating a smaller number of times of permission than the code value A of the complementary source pixel does not exist, the non-ejection complementary processing for the complementary pixel group selected in step S902 is terminated, and the processing proceeds to step S908.
Then, in step S908, whether the processing in steps S903 to S907 has been executed for all the complementary pixel groups that include at least one pixel corresponding to the ejection defective nozzle is determined. When it is determined that the complementary pixel group for which the processing in steps S903 to S907 has not yet been executed remains, the processing returns to S902, and the processing in steps S903 to S907 is executed for the remaining complementary pixel group. Meanwhile, when it is determined that the processing in steps S903 to S907 has been executed for all the complementary pixel groups, the non-ejection complementary processing is terminated, and the finally obtained mask pattern is updated as the mask pattern to be used for generation of the print data.
An effect similar to that of the first to fourth embodiments can be obtained even when the non-ejection complementary processing as described above is performed.
Sixth EmbodimentIn the first to fifth embodiments, forms of using the mask patterns having b (b≧2)-bit information per pixel have been described.
In contrast, in the present embodiment, a form of using mask patterns having one-bit information per pixel will be described.
Note that description of portions similar to the first to fifth embodiments is omitted.
The image data in the present embodiment is configured from two-bit information per pixel, and any of three pixel values “00”, “01”, and “10” is allocated to each pixel. Here, when the pixel value is “00”, an ink is not ejected to a corresponding pixel even once. Further, when the pixel value is “01”, the ink is ejected to the corresponding pixel once. Further, when the pixel value is “10”, the ink is ejected to the corresponding pixel twice.
Further, the mask pattern in the present embodiment is configured from one-bit information per pixel, and any of two code values “0” and “1” is allocated to the mask pattern.
Here, when the code value is “0”, as can be seen by reference to the decoding table illustrated in
Further, when the code value is “1”, while the ink is not ejected when the pixel value in the corresponding pixel is “00”, the ink is ejected when the pixel values are “01” and “10”. That is, the code value “1” corresponds to permission of ejection of ink twice for the three pixel values (the number of times of permission of ejection of ink is twice).
By use of such image data, mask patterns, and decoding table, in a two-pass printing method where printing is performed by twice of scanning to a unit area on a printing medium, the number of times of ejection from zero times to twice can be expressed for pixels.
In the present embodiment, when the two-pass printing method is executed using such image data, mask patterns, and decoding table, the non-ejection complementary processing illustrated in
Here, the first line of
When the code value of the complementary source pixel is “0”, the code value allocated to the pixel corresponding to the ejection normal nozzle in the mask pattern before the non-ejection complementary processing is “1”. Therefore, when the mask patterns before the non-ejection complementary processing are used, ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “00” and “01” while an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “10”. Meanwhile, the code value allocated to the pixel corresponding to the ejection normal nozzle in the mask pattern after the non-ejection complementary processing is also “1”. Therefore, ideal numbers of times of ejection of ink can be expressed when the pixel values of the image data are “00” and “01” while an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “10”.
Meanwhile, when the code value of the complementary source pixel is “1”, the code values allocated to the pixels corresponding to the ejection normal nozzles in the mask patterns before the non-ejection complementary processing are “00”, “10”, and “11”. Therefore, when the mask patterns before the non-ejection complementary processing are used, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00”. However, an ideal number of times of ejection of ink cannot be expressed when the pixel values of the image data are “01” and “10”. Meanwhile, the code value allocated to the pixel corresponding to the ejection normal nozzle in the mask pattern after the non-ejection complementary processing is “1”. Therefore, an ideal number of times of ejection of ink can be expressed when the pixel value of the image data is “00” while an ideal number of times of ejection of ink cannot be expressed when the pixel value of the image data is “10”. Further, when the mask patterns after the non-ejection complementary processing are used, an ideal number of times of ejection can be expressed when the pixel value of the image data is “01”.
Seventh EmbodimentIn the first to sixth embodiments, forms of performing printing by a plurality of times of print scanning to a unit area on a printing medium have been described.
In contrast, in the present embodiment, in a printing apparatus that performs printing by performing relative print scanning of printing heads and the printing medium once, using a plurality of printing heads corresponding to respective inks having a length corresponding to the entire region in a width direction (Z direction) of the printing medium, an ejection order of the plurality of inks is controlled.
Note that description of similar portions to the first to sixth embodiments is omitted.
In four printing heads 601 to 604, a predetermined number of ejection ports (not illustrated) that eject inks of yellow (Y), magenta (M), photo magenta (Pm), cyan (C), photo cyan (Pc), black (Bk) are arrayed in the Z direction per one printing head (ejection port array group). Therefore, four ejection port arrays that eject one color of ink are arrayed in total in the printing heads 601 to 604. The length of the ejection port array in the Z direction is the length of a printing medium 3 in the Z direction or more so that the printing can be performed on the entire region on the printing medium 3 in the Z direction. These printing heads 601 to 612 are arranged side by side in a W direction intersecting with the Z direction. Note that the four printing heads 601 to 604 are also collectively called printing unit.
A conveying belt 400 is a belt for conveying the printing medium 3, and conveys the printing medium 3 from a feeding portion 401 to a discharging portion 402 in the W direction intersecting with the Z direction by rotation of the conveying belt 400.
In this image printing apparatus, an image can be completed by one-time print scanning. Therefore, reduction of printing time can be achieved.
In the present embodiment, image data is distributed to the four ejection port arrays that eject the same color of ink in the printing heads 601 to 604 illustrated in
Further, the length of the ejection port array used in the present embodiment in the Z direction is the length corresponding to the width of the printing medium. However, a so-called connecting head that is made long by arraying a plurality of short ejection port arrays in the Z direction can be used as the printing head.
In the above-described embodiments, forms using the decoding table illustrated in
If the decoding table illustrated in
Meanwhile, if the decoding table illustrated in
Further, when the code value is “10”, the ink is not ejected when the pixel values in the corresponding pixels are “00”, “01”, and “10”, but the ink is ejected when the pixel value is “11”. That is, the code value “10” corresponds to permission of ejection of ink once for the four pixel values (the number of times of permission of ejection of ink is once).
Further, when the code value is “11”, the ink is not ejected when the pixel values in the corresponding pixels are “00” and “01”, but the ink is ejected when the pixel values are “10” and “11”. That is, the code value “11” corresponds to permission of ejection of ink twice for the four pixel values (the number of times of permission of ejection of ink is twice).
When using such a decoding table, the code values of the mask patterns are “00”, “10”, “11”, and “10” in increasing order of the number of times of permission of ejection of ink. Therefore, for example, when the code values of the complementary destination candidate pixels acquired in step S705 are “00” and “11”, the code value “00” may just be selected as the code value B of the complementary destination pixel in step S706. Further, for example, when the code values of the complementary destination candidate pixels acquired in step S705 are “01”, “10”, and “11”, the code value “10” may just be selected as the code value B of the complementary destination pixel in step S706.
Other EmbodimentsEmbodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.
Further, in the embodiments, so-called thermal jet-type ink jet printing apparatus and printing method, which eject inks by energy of bubbling caused by heating, have been described. However, the present invention is not limited to the thermal jet-type ink jet printing apparatus. For example, the present invention can be effectively applied to various image printing apparatuses such as a piezo-type ink jet printing apparatus that ejects inks using piezoelectric transducers.
Further, in the embodiments, an image printing method using an image printing apparatus has been described. However, an image processing apparatus, an image processing method, and a program, which generate data for performing the image printing method described in the embodiments, can be applied to a form prepared in a separate body from the image printing apparatus. Further, the image processing apparatus, the image processing method, and the program can be widely applied to a form included in a part of the image printing apparatus.
Further, the “printing medium” includes not only paper used in a typical printing apparatus, but also ones that can accept inks such as fabric, plastic films, metal plates, glass, ceramics, wood, and leather.
Further, the “ink” means a liquid that can be provided for formation of an image, a design, a pattern, and the like, processing of the printing medium, or processing of an ink (for example, solidification or insolubilization of a colorant in the ink provided for the printing medium) by being provided on the printing medium.
According to the image processing apparatus and the image processing method of the present invention, print data to be used for printing can be generated so that favorable complement printing can be performed when ejection failure of an ejection port is caused even when printing is performed to eject a plurality of times of ink to one pixel region.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Claims
1. An image processing apparatus that generates print data used for K (K≧3) times of relative scanning to a unit area on a printing medium, the relative scanning being performed by a printing head that ejects ink, the image processing apparatus comprising:
- an acquiring unit configured to acquire image data, information indicating a number of times of ejection of ink from zero to N (2≦N≦K) times for each of a plurality of pixel regions in the printing medium being determined for each of a plurality of pixels in the image data; and
- a generation unit configured to generate the print data corresponding to the K times of scanning based on the image data and K mask patterns, information indicating a number of times of permission for ejection of ink from zero to N times for each of the plurality of pixel regions being determined for each of the plurality of pixels in the K mask patterns,
- wherein, among K pixels in the K mask patterns each corresponding to a same pixel region, (i) for N pixels, information indicating different numbers of times of permission is determined, the different numbers being varied from one to N, and (ii) for K−N pixels, information indicating that the number of times of permission is zero is determined.
2. The image processing apparatus according to claim 1, wherein the generation unit generates the printing data by using a table in which ejection or non-ejection of ink for each of the plurality of pixel regions is defined in accordance with the information determined in the image data and the information determined in the mask pattern.
3. The image processing apparatus according to claim 2, wherein the table defines (i) ejection of ink in a case where the number of times of permission indicated by information determined in the image data is M (1≦M≦N) times and the number of time of permission indicated by the information determined in the mask pattern is L (1≦L≦N) times, and (ii) non-ejection of ink in a case where the number of times of permission indicated by information determined in the image data is M times and the number of time of permission indicated by the information determined in the mask pattern is L−1 times.
4. The image processing apparatus according to claim 3, wherein the table defines non-ejection of ink in a case where the number of time of ejection indicated by the information determined in the image data is M−1 times and the number of times of permission indicated by the information determined in the mask pattern is L times.
5. The image processing apparatus according to claim 4, wherein M+L=N+1.
6. The image processing apparatus according to claim 1, wherein numbers of pixels in which information indicating a same number of times of permission is determined are substantially same among the K mask patterns.
7. The image processing apparatus according to claim 1, wherein the information determined in the image data and the information determined in the mask pattern are each a (a≧2)-bit information.
8. The image processing apparatus according to claim 7, wherein N=(2̂a)−1.
9. The image processing apparatus according to claim 1, wherein N<K.
10. The image processing apparatus according to claim 1, wherein K=4 and N=3.
11. The image processing apparatus according to claim 1, further comprising the printing head.
12. The image processing apparatus according to claim 1, further comprising a storing unit configured to store the K mask patterns.
13. An image processing apparatus that generates printing data used for K (K≧3) times of relative scanning to an unit area on a printing medium, the relative scanning being performed by a printing head that ejects ink, the image processing apparatus comprising:
- an acquiring unit configured to acquire image data, information indicating a number of times of ejection of ink from zero to K times for each of a plurality of pixel regions in the printing medium being determined for each of a plurality of pixels in the image data; and
- a generation unit configured to generate the print data corresponding to the K times of scanning based on the image data and K mask patterns, information indicating a number of times of permission for ejection of ink from once to K times for each of the plurality of pixel regions being determined for each of the plurality of pixels in the K mask patterns,
- wherein, in K pixels in the K mask patterns each corresponding to a same pixel region, information indicating different numbers of times of permission is determined, the different numbers being varied from one to N.
14. The image processing apparatus according to claim 13, wherein the generation unit generates the printing data by using a table in which ejection or non-ejection of ink for each of the plurality of pixel regions is defined in accordance with the information determined in the image data and the information determined in the mask pattern.
15. The image processing apparatus according to claim 14, wherein the table defines (i) ejection of ink in a case where the number of times of permission indicated by information determined in the image data is M (1≦M≦K) times and the number of time of permission indicated by the information determined in the mask pattern is L (1≦L≦K) times, and (ii) non-ejection of ink in a case where the number of times of permission indicated by information determined in the image data is M times and the number of time of permission indicated by the information determined in the mask pattern is L−1 times.
16. The image processing apparatus according to claim 15, wherein the table defines non-ejection of ink in a case where the number of time of ejection indicated by the information determined in the image data is M−1 times and the number of times of permission indicated by the information determined in the mask pattern is L times.
17. The image processing apparatus according to claim 13, wherein numbers of pixels in which information indicating a same number of times of permission is determined are substantially same among the K mask patterns.
18. The image processing apparatus according to claim 13, wherein the information determined in the image data and the information determined in the mask pattern are each a (a≧2)-bit information.
19. A method for generating print data used for K (K≧3) times of relative scanning to a unit area on a printing medium, the relative scanning being performed by a printing head that ejects ink, the method comprising:
- acquiring image data, information indicating a number of times of ejection of ink from zero to N (2≦N≦K) times for each of a plurality of pixel regions in the printing medium being determined for each of a plurality of pixels in the image data; and
- generating the print data corresponding to the K times of scanning, based on the image data and K mask patterns, information indicating a number of times of permission for ejection of ink from zero to N times for each of the plurality of pixel regions being determined for each of the plurality of pixels in the K mask patterns,
- wherein, among K pixels in the K mask patterns each corresponding to a same pixel region, (i) for N pixels, information indicating different numbers of times of permission is determined, the different numbers being varied from one to N, and (ii) for K−N pixels, information indicating that the number of times of permission is zero is determined.
20. A method for generating printing data used for K (K≧3) times of relative scanning to an unit area on a printing medium, the relative scanning being performed by a printing head that ejects ink, the method comprising:
- acquiring image data, information indicating a number of times of ejection of ink from zero to K times for each of a plurality of pixel regions in the printing medium being determined for each of a plurality of pixels in the image data; and
- generating the print data corresponding to the K times of scanning based on the image data and K mask patterns, information indicating a number of times of permission for ejection of ink from once to K times for each of the plurality of pixel regions is determined for each of the plurality of pixels in the K mask patterns,
- wherein, in K pixels in the K mask pattern each corresponding to a same pixel region, information indicating different numbers of times of permission is determined, the different numbers of times being varied from one to N.
Type: Application
Filed: Aug 7, 2017
Publication Date: Nov 23, 2017
Inventors: Hajime Nagai (Kawasaki-shi), Yoshinori Nakajima (Yokohama-shi)
Application Number: 15/670,851