Abstract: The present invention provides a printing control method of generating print data to be supplied to a print unit to print. The print unit comprises a print head having a plurality of nozzles and a plurality of ejection drive elements for ejecting an ink from the plurality of nozzles, and is capable of selectively forming one of N types of dots having different sizes at one pixel area with each nozzle. The print control method comprises a dot data generation step of generating dot data representing a state of dot formation at each pixel according to given image data. The dot data generation step includes a step of generating the dot data with a specific dot data generation step for at least a part of the ink types when a printing environment is a specific environment. The specific dot data generation step includes a step of generating the dot data using only a part of dot types among the N types of dots.

Abstract: An image processing apparatus of the invention refers to a color conversion table, which represents a mapping of first image data expressed in a first color system to second image data expressed in a second color system, so as to attain color conversion of first image data into second image data. The second image data stored in the color conversion table have gone through an encoding process, which enhances a variation in tone value of the second image data in a predetermined tone area while compressing the variation in tone value of the second image data in a residual tone area. The color conversion process decodes the color conversion table, reconstructs the decoded color conversion table, again encodes the reconstructed color conversion table, refers to the encoded color conversion table for color conversion, and decodes the resulting encoded second image data. This arrangement ensures highly accurate color conversion.

Abstract: Pixels are grouped into groups of pixels, comprising a plurality of pixels each, and representative tone values are determined for each of a plurality of regions into which the groups of pixels are split. Decisions are made as to whether or not to output dots to the individual pixels in the group of pixels based on the multilevel halftoning resultant values obtained through performing multilevel halftoning on the representative tone values, to thereby output an image. The multilevel halftoning resultant values can accelerate the creation and transfer of data, enabling rapid outputting of images.

Abstract: A printing system of the invention successively forms rasters or dot lines on a printing medium to complete a printed image. A raster formation assembly is scanned in a raster-forming direction relative to the printing medium and completes each raster on the printing medium by a preset number of multiple main scans. The printing system of the invention determines the dot on-off state of respective pixels included in an object image according to image data of the object image, stores data representing the determination results in a classified manner in a memory, and supplies data of each group read from the classified storage in the memory to the raster formation assembly. The determination results representing the dot on-off state of plural pixels on each raster are classified and stored into multiple groups according to allocation of the preset number of multiple main scans to raster formation in the plural pixels on the raster.

Abstract: A printing control method of generating print data to be supplied to a print unit capable of forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises a tone-decreasing step which includes the step of generating transparent dot data by a process configured such that size of first processing-targeted pixels is larger than size of second processing-targeted pixels, the first processing-targeted pixels being targeted for processing in the transparent dot data generating process, the second processing-targeted pixels being targeted for processing in the colored dot data generating process.

Abstract: A liquid ejection device of the invention is constructed to eject a liquid to an ejection object. The liquid ejection device has a dot data generator configured to generate dot data from given image data, where the dot data represents a dot creation state in each pixel set on the ejection object. The liquid ejection device also has a liquid ejector equipped with a nozzle array including multiple nozzles aligned in a specific direction substantially perpendicular to a scanning direction. The liquid ejector makes multiple scans of the nozzle array in the scanning direction in a common printing area according to the generated dot data and ejects the liquid to the ejection object to create dots. The dot data generator has a specific print mode that generates corrective dot data by skipping a virtual dot array created by one scan from a group of dot arrays to be created by the multiple scans of the nozzle array, in order to prevent a potential contact with a dot array to be created by another scan.

Abstract: This invention is a printing control apparatus for generating print data to be supplied to a print unit to print. The print unit is capable of forming dots on a print medium by ejecting at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control apparatus includes an outline area extractor configured to extract an outline area of an image expressed by given image data and a dot data generator configured to generate colored dot data and transparent dot data according to the image data. The dot data generator is configured to reduce ink volume of dots formed in the outline area among the transparent dots.

Abstract: A printing control method of generating print data to be supplied to a print unit capable of forming dots on a print medium by ejecting ink droplets of at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises a tone-decreasing step which includes the step of generating transparent dot data by a process configured such that size of first processing-targeted pixels is larger than size of second processing-targeted pixels, the first processing-targeted pixels being targeted for processing in the transparent dot data generating process, the second processing-targeted pixels being targeted for processing in the colored dot data generating process.

Abstract: In a printing process with a print head having multiple dot formation elements for creating dots, an overlap printing technique that uses at least two dot formation elements for formation of each raster line requires a large memory capacity for storage of dot data. In a printing system of the invention, an image processing device takes charge of a former part of image processing and outputs intermediate data in a state requiring expansion into multiple pixels to a printing device. The printing device expands intermediate data including a target pixel, for which a dot on-off state is to be specified, and specifies the dot on-off state in the target pixel based on the intermediate data. Every time the dot on-off state is specified in each target pixel, intermediate data including the target pixel is expanded. This arrangement does not require the printing device to have a large storage capacity for the image processing.

Abstract: A plurality of types of positional shift postulated patterns are postulated wherein the positional shift of print head tips in a printer are postulated to have positional shift directions and distances. For each of the postulated positional shift postulated patterns, a base dithering mask is generated considering the ability to produce excellent dot dispersion characteristics when this postulated positional shift has occurred. Additionally, optimal dithering masks are generated through multiply combining the sets of threshold values that comprise the base dithering masks. Doing so enables the suppression of degradation of printed image quality, even when there are positional shifts between the print heads, in a half toning process for printing using a printer that is provided with a plurality of print heads that are arranged in a line across a printing range.

Abstract: A printer uses a dithering mask having a width that is 1/N (where N is a nonzero positive integer) times a number of pixels corresponding to the layout pitch of print head tips, so as to always have an identical positional relationship between the dithering mask and the connecting portions of the print head tips, so as to perform a half toning process and print image data. The dithering mask DM is a dithering mask that is optimized so as to be able to obtain dot dispersion characteristics that are somewhat good regardless of the positional shift patterns between the print head tips. Doing so enables the suppression of degradation of printed image quality that stems from differences in characteristics of the plurality of print heads in a line printer that performs printing using a plurality of print heads that are arrayed across a printing range.

Abstract: For image processing for repeatedly executing process segment sets including N (N is an integer of 3 or greater) unit process segments Lc, Lm, Ly, Lk, Llc, Llm and Ldy, unit process segments are executed by M (M is an integer of 2 or greater but less than N) processing units. The unit process segments include a first-type unit process segments Lc, Llc, Llm, and Lk for performing processing using a first processing method and a second-type unit process segment Lm, Ly and Ldy for performing processing using a second processing method that is different from the first processing method. Then, when executing process segment sets, the M unit process segments including at least one each of the first-type and the second-type unit process segments Lc, Lm are first executed on the M processing units.

Abstract: For image processes performed repeatedly using a plurality of processing units on a plurality of partial images aligned mutually adjacent to each other, specified processing is performed. This image process includes (i) a first-type process segment on first partial image data representing a partial image to generate M types (M is an integer of 2 or greater) of second partial image data; and (ii) the respectively corresponding M types of second-type process segments on the M types of second partial image data. When executing image processing, parallel processing is performed for the second-type process segment relating to the i-th (i is a positive integer) partial image and the first-type process segment relating to any of the (i+1)-th to the (i+p)-th (p is a positive integer) partial images.

Abstract: The invention provides a printing method of performing printing on a print medium. The method includes: generating dot data representing a status of dot formation on each of print pixels of a print image to be formed on the print medium, by performing a halftone process on image data representing a input tone value of each of pixels constituting an original image; providing a print head and a platen; setting a platen gap as a distance between the print head and the platen to a single fixed value that is commonly applied to plural printing environments; and performing a main scan of the print head to form a dot in each of the print pixels on the print medium supported by the platen according to the dot data in each of a forward pass and a backward pass of the print head, for generating the print image.

Abstract: The invention provides a printing method of printing on a printing medium. The method includes: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; providing a print head capable of selectively forming N types of dots having mutually different sizes on a region of one pixel on the printing medium, N being an integer of at least 2; and generating the print image according to the dot data by mutually combining a plurality of dot groups in a common print region, each of the plurality of dot groups being formed on each of a plurality of pixel groups that assume mutually physical differences in a process of dot formation.

Abstract: In image processing carried out by means of repeated execution of process set which includes N unit processes (where N is an integer equal to 3 or greater), prior to execution of the process groups, the N unit processes are assigned to a number M (where M is an integer equal to 2 or greater, but less than N) of processing modules for executing the unit processes. First, on the basis of execution results of unit processes included in the process group executed immediately prior, there is estimated an estimated load of unit processes of each class in the next process group. Then, on the basis of the estimated load, the N unit processes are assigned to the processing modules. During this process, a selected unit process which is one of the unit processes not yet assigned to a processing module, is assigned to one of the processing modules.

Abstract: A computer serving as an image processing device produces pixel groups by assembling a plurality of adjacent pixels among the plurality of pixels forming the image data, and determines the pixel group tone value for each pixel group. Number data corresponding to the pixel tone values of the pixel groups is then obtained based on a predetermined correspondence. At that time, tone errors occurring during the conversion of the pixel group tone value to number data are diffused to the surrounding pixel groups so as to be reflected in the calculation of the pixel group tone values. The computer outputs the resulting number data to a printer. The printer, which serves as an image generating device, determines the position of the pixels by which the dots are formed in the pixel groups based on the number data that has been obtained, and drives a printing head to form dots in those positions.

Abstract: A plurality of same ink nozzle arrays are provided, and multiple color patches are printed with mutually different dot recording rates respectively using one of the same ink nozzle arrays. Color specification value of the plurality of color patches is measured for each same ink nozzle array. The ink ejection amount error of each same ink nozzle array is determined based on the color specification values of the plurality of color patches for each same ink nozzle array. It is also possible to select among the plurality of color patches a preferable color patch that is closest to a specified reference color patch, and to determine the ink ejection amount error from the dot recording rate of the preferable color patch.

Abstract: The image processing apparatus or the printing device of the present invention forms units by grouping adjacent multiple-pixels and converts the image data to the dot data representing dot on/off state for each of pixels. The apparatus stores the dot data in a condition enabling identification of the dot on/off state for at least one of pixels within the previously converted units. When the apparatus converts the image data to the dot data by a unit, The apparatus serially specifies a interested pixel, within a unit to be converted to the dot data, for determination of dot on/off state. Then the apparatus determines the dot on/off state for the interested pixel, according to a characteristic that controls the proportion of a number of dots formed at the predetermined location of the unit against a number of all dots into a predetermined range. It prevents cyclical patterns from becoming visible and degrading image quality.

Abstract: This invention is a printing control method of generating print data to be supplied to a print unit which is capable of forming dots on a print medium by ejecting at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises a color conversion step of converting pixel values into multiple gradation data of each ink, the pixel values representing color of each pixel of given image data, the multiple gradation data of each ink expressing the color of the pixel by using the colored ink and the quality-enhancing ink available in the print unit and a gradation-reduction step of generating at least part of colored dot data and transparent dot data by ordered dither method.