Abstract: The printing apparatus includes a comparator, a threshold setting section, and an error diffusion section. The comparator compares a first threshold which is aligned with a dither mask and the image data. The threshold setting section sets a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold according to results of the comparing, and sets the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area when it is determined that the image data exceeds the first threshold. The error diffusion section generates the dot data and to calculate distribution to pixels in the vicinity of gradation errors by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold.

Abstract: When dot data indicating whether or not a dot is to be formed is formed based on the gradation value for each pixel forming an image, dots belonging to a plurality of pixel groups are printed in a common region in an overlapping manner, and the distribution of dots formed in the common region has a noise characteristic possessing a peak in the spatial frequency region on the high-frequency side. In a case where first and second pixels belonging, respectively, to two pixel groups are proximal pixels in the common region in a predetermined gradation range in which probabilities k1 and k2 at which a dot is formed in the first and second pixels are such that k1<0.5 and k2<0.5, a probability K of a dot being formed in both of the proximal pixels is set to be close to k1·k2.

Abstract: An image data processing apparatus processes previously halftoned data that has been halftoned so that a proportion of dot formation corresponding to gradation values of an image reaches a first dot generation rate, as image data representative of the image. The image data processing apparatus includes a re-halftone processing unit configured to carry out a re-halftone process by using an error diffusion technique based on first gradation values corresponding to ON-dots in the previously halftoned data, and an ON-dot gradation value setting unit configured to set second gradation values corresponding to the ON-dots in the re-halftone process using the error diffusion technique, such that the dot generation rate in the re-halftone process reaches a second dot generation rate different from the first dot generation rate.

Abstract: An image processing device includes a processing device that performs a color reduction processing of converting data of a-levels of gray indicative of an image to be displayed in a display area including a plurality of pixels arranged along a first direction and a second direction into data of b-levels of gray (b<a) and, upon receiving an input of data for reducing the number of pixels with a first gray level in the display area to 50%, generates a result in which the arrangement of the pixels with the first gray level has blue noise characteristics in the display area, and the maximum value of the rate of occurrence of specific patterns in the display area is less than 7.0%.

Abstract: A printing apparatus includes an input unit, a color converting section, a head, a gradation number converting processing section, a printing section, and a gradation number converting processing section. The gradation number converting processing section converts the ink amount data into an expected value for forming each of the dots for each of the inks with the hues and generates dot data which represents whether or not each of the dots is formed for each of the pixels based on the expected value. The gradation number converting processing section includes a dot converting section configured to perform converting, where the expected value for forming of dots in the plurality of types is determined from the ink amount data, according to the color image data in at least a portion of the color image data for at least one of the inks with the hues.

Abstract: A printing device includes the following features. The first dot group in which dots are formed based on the first printing condition and the second dot group in which dots are formed based on a printing condition which is different from the first printing condition are formed together in a common region. In the common region, when the printing is performed in a plurality of conditions such that a difference of the dot pitch between a formation position of dots belonging to the first pixel group and a formation position of dots belonging to the second pixel group is 2/720 inch to 5/720 inch, the change in CIEL*a*b* of the printed image is within the preliminary determined range.

Abstract: The printing apparatus includes a comparator, a threshold setting section, and an error diffusion section. The comparator compares a first threshold which is aligned with a dither mask and the image data. The threshold setting section sets a second threshold which is used in the error diffusion method to one of a low threshold and a high threshold according to results of the comparing, and sets the low threshold to a value which is smaller than a gradation range of the image data in at least a low gradation area when it is determined that the image data exceeds the first threshold. The error diffusion section generates the dot data and to calculate distribution to pixels in the vicinity of gradation errors by comparing correction data where error distribution in the image data is complete using the error diffusion method and the low threshold or the high threshold.

Abstract: A printing apparatus includes a dot data generating section configured to: compare a first threshold which is aligned with a dither mask and a corresponding gradation value which corresponds with the image data which is input; generate the dot data by determining that dots are to be formed in a case where it is determined that the corresponding gradation value exceeds the first threshold and generate the dot data by determining the forming of dots due to application of an error diffusion method by comparing correction data, where error diffusion in the image data is complete, and a second threshold in a case where it is determined that the corresponding gradation value does not exceed the first threshold as a result of the comparing; and diffuse errors, which occur as a result of generating the dot data, to pixels in a predetermined range in the vicinity in both cases.

Abstract: When dot data indicating whether or not a dot is to be formed is formed based on the gradation value for each pixel forming an image, dots belonging to a plurality of pixel groups are printed in a common region in an overlapping manner, and the distribution of dots formed in the common region has a noise characteristic possessing a peak in the spatial frequency region on the high-frequency side. In a case where first and second pixels belonging, respectively, to two pixel groups are proximal pixels in the common region in a predetermined gradation range in which probabilities k1 and k2 at which a dot is formed in the first and second pixels are such that k1<0.5 and k2<0.5, a probability K of a dot being formed in both of the proximal pixels is set to be close to k1·k2.

Abstract: A host computer generates pseudo-pixels by grouping pixels together. RGB representative values are assigned to the pseudo-pixels, which are then transferred to a printer. Meanwhile, for pixels that configured pseudo-pixels having an edge strength selected so that the transfer data amount is less than or equal to a predetermined value, the host computer carries out a halftone process and then transfers the dot data generated as a result to the printer. The printer then prints based on the transferred dot data and the representative values.

Abstract: A host computer groups a plurality of pixels to generate pseudo pixels, assigns representative values in an RGB format to the pseudo pixels, and transfers the representative values to a printer. Further, the host computer performs halftone processing and transfers generated dot data to the printer for pixels constituting the pseudo pixel which includes edges therein or of which boundary is the edge. The printer performs printing by using the transferred dot data and the representative values.

Abstract: An image data processing apparatus processes previously halftoned data that has been halftoned so that a proportion of dot formation corresponding to gradation values of an image reaches a first dot generation rate, as image data representative of the image.

Abstract: A printing device includes the following features. The first dot group in which dots are formed based on the first printing condition and the second dot group in which dots are formed based on a printing condition which is different from the first printing condition are formed together in a common region. In the common region, when the printing is performed in a plurality of conditions such that a difference of the dot pitch between a formation position of dots belonging to the first pixel group and a formation position of dots belonging to the second pixel group is 2/720 inch to 5/720 inch, the change in CIEL*a*b* of the printed image is within the preliminary determined range.

Abstract: A printing apparatus which forms dots, according to dot data generated through comparison of a grayscale value of each of pixels with each of threshold values of a dither mask. The printing apparatus forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the pixel groups in a common region. The dither mask has a second threshold value disposition, with respect to a first threshold value disposition which is each of dispositions of the respective threshold values set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region.

Abstract: When dot data indicating whether or not a dot is formed on the basis of the gradation value for each pixel, dots belonging to a plurality of pixel groups having different printing conditions are printed in a common region in an overlapping manner, and the distribution of dots in the common region has a noise characteristic possessing a peak in the spatial frequency region on the high-frequency side. In a case where first and second pixels belonging to two pixel groups are proximal pixels in the common region in a predetermined gradation range in which probabilities k1 and k2 at which a dot is formed in the first and second pixels are such that k1<0.5 and k2<0.5, a probability K of a dot in both of the proximal pixels is set to be close to k1·k2.

Abstract: A printing apparatus is provided with a CPU. The CPU generates dot data where dots are regularly distributed and arranged in a case where gradation values which are represented by image data are a predetermined value or less by using a dither mask where thresholds are set for each printing pixel and comparing the gradation values of each of the pixels which configure the original image and the thresholds for each of the printing pixels which are set in the dither mask, and generates the dot data such that the degree of regularity of the dots which are distributed and arranged is reduced as the gradation values are increased in a case where the gradation values which are represented by the image data exceed the predetermined value through execution of a dot data generating module.

Abstract: A printing device includes the following features. The first dot group in which dots are formed based on the first printing condition and the second dot group in which dots are formed based on a printing condition which is different from the first printing condition are formed together in a common region. In the common region, when the printing is performed in a plurality of conditions such that a difference of the dot pitch between a formation position of dots belonging to the first pixel group and a formation position of dots belonging to the second pixel group is 2/720 inch to 5/720 inch, the change in CIEL*a*b* of the printed image is within the preliminary determined range.

Abstract: Provided is an image processing device for comparing a determination value adjusted by comparing the gradation values of pixels included in inputted image data and threshold values of a dither mask prepared in advance, and a corrected gradation value obtained by correcting the gradation value of the pixel by the diffusion error from an adjacent processed pixel; adjusting a determination value; generating dot data which indicate the presence or absence of the dot formation by applying error diffusion; and reducing the width of the adjustment of the determination value used in determining the dot formation so that the width of the adjustment is smaller in comparison with non-edge pixels in the case that a pixel is determined to be an edge pixel for which the difference in gradation value in relation to an adjacent pixel is equal to or greater than a predetermined value.

Abstract: An image is divided into first a second regions on the basis of inputted image data, and a comparison is made between the gradation values of pixels in the first region and threshold values corresponding to the pixels of the first region of a dither mask. The results of the comparison are referenced to determine whether or not dots are formed in the pixels of the first region. Errors are calculated based on the results of determining the first boundary pixels, which are in the first region near the boundary between the first region second regions. Some of the errors are distributed as diffusion errors to pixels in the second region near the boundary. The diffusion errors distributed from the first boundary pixels are added, and it is determined whether or not dots are formed by the error diffusion method in the pixels of the second region.

Abstract: A printing device for discharging ink from a print head to print an image includes a detection unit configured to detect pixels of at least a high-concentration side of an edge of the image as edge pixels based on image data including plurality of pixels, a halftone processing unit configured to create dot data expressing whether or not dots are formed based on the image data, and a printing unit configured to print the image by combining together dots formed at multiple different timings in a common print region of a print medium. The halftone processing unit is configured to create the dot data so that dots are formed disproportionately towards one of the multiple timings in positions on the print medium where dots corresponding to the edge pixels are formed.