Abstract: Multi-valued image data corresponding to a pixel area is divided into the first scanning multi-valued data, first and second scanning common multi-valued data, and second scanning multi-valued data. A quantization processing is executed on each of the multi-valued data to generate first scanning quantized data, first and second scanning common quantized data, and second scanning quantized data. After that, these pieces of quantized data are combined for each scanning to generate first scanning combined quantized data and second scanning combined quantized data. According to this, the amount of pixels where dots are both recorded by performing a scanning by plural times (the amount of overlapping dots) is controlled, and while suppressing the image density variations, the granularity is held to a low level.

Abstract: The present invention suppresses data processing load and processing time when generating density data for the same color that corresponds to a plurality of printing scans (or plurality of printing element groups) of a printing head and printing medium. In order to accomplish this, input image data is converted to a plurality of density data by referencing a three-dimensional lookup table that performs one-to-one correlation of input image data with a plurality of density data that corresponds to a plurality of relative movements (or plurality of printing element groups). By doing so, it is possible to perform a process of generating density data (CMYK) that corresponds to a plurality of relative movements (or plurality of printing element groups) from input image data at once, and thus it is possible to suppress an increase in data processing load and processing time.

Abstract: The image processing apparatus executes quantization processing of second multi-valued image data that corresponds to a second relative movement of a plurality of relative movements based on first multi-valued image data that corresponds to a first relative movement of the plurality of relative movements, and executes quantization processing of the first multi-valued image data based on the second multi-valued image data. This makes it possible to output a high-quality image having excellent robustness and reduced graininess by controlling the overlap rate of dots that are printed by the first relative movement and the dots that are printed by the second relative movement.

Abstract: When recording is performed in a pixel region by M (M is an integer equal to or larger than 2) passes with N (N is an integer equal to or larger than 2) recording element groups, density variation due to a deviation between recording positions of dots that are recorded by different passes is suppressed while a load of data processing is decreased. First, multivalued image data (24-1 to 24-2) corresponding to the M passes is generated from input image data, and the multivalued image data corresponding to the M passes is quantized to generate quantized data (26-1 to 26-2) corresponding to the M passes. Then, the quantized data corresponding to the M passes is divided into quantized data being complements of each other and corresponding to the N recording element groups. Accordingly, the quantized data (28-1 to 28-4) corresponding to the M passes for the N recording element groups is obtained.

Abstract: A printing apparatus and a printing method are provided which, even if a print position misalignment occurs between a plurality of print scans during a multipass printing, can minimize density variations in a unit area reliably and stably, thus producing an image without density unevenness. For this purpose, multi-grayscale-level image data is converted into a plurality of dot arrangement patterns that determine individual subpixels either to be printed or not to be printed with a dot. Then, these dot arrangement patterns are printed overlappingly on a print medium in different print scans of the print head. At this time, the plurality of dot arrangement patterns are so arranged that, if these dot arrangement patterns are shifted from one another, a change in the dot-overlapping area ratio will be smaller than when the dots are arranged separately so that they do not overlap one another.

Abstract: To provide a printing apparatus and a printing method capable of not permitting a printable ratio of each printing scan to have a deviation and, even if a sudden conveyance shift occurs, outputting a uniform and smooth image in the whole area of the print medium. In order to achieve this, when performing multipass printing of 2M passes, a mask such that a printable area overlapping ratio that relates to straddling between Pass M and Pass M+1 is set higher than the printable area overlapping ratio that relates to straddling between other two consecutive passes is used. By this configuration, even if a complementary relationship of dots collapses due to a sudden conveyance shift etc. and thereby a density reduction is anticipated, by an overlapped dot being separated, increase of the density is accelerated, and it becomes possible to mitigate the above-mentioned density reduction.

Abstract: In a 2M-pass printing operation that forms dots including overlapping dots, this invention makes an arrangement to ensure that the number of overlapping dots that are printed in a unit area in pairs of passes each straddling a print medium convey operation executed between an Mth pass and an (M+1)st pass is greater than the number of overlapping dots that are printed in pairs of passes straddling any other convey operation. This arrangement can cause two dots of the overlapping dots to be separated from each other in the event of a print position misalignment, preventing a possible density fall even in a unit area where the largest density reduction is feared to occur at time of the print position misalignment.

Abstract: Provided is an inkjet printing apparatus for performing a printing with a first nozzle array for ejecting a first color ink and a second nozzle array for ejecting a second color ink. The apparatus reduces density unevenness stemming from a sudden error in conveyance of a printing medium. When the apparatus performs a scan with respect to the printing medium for printing in which using ranges of nozzles in the first and second nozzle arrays are restricted to parts thereof, the restricted using ranges of the first and second nozzle arrays are shifted from each other. Thereby, the density unevenness stemming from the error in conveyance occur in positions which are different between the first and second colors, Thus, it possible to make the overall density unevenness less obvious by making gradients of variations in brightness and chroma of an image smaller.