Patent ID: 9616659
Date: 2017-04-11
CPC Classifications: B41J,H04N

Claim:
1. An image processing apparatus for controlling a print execution unit, wherein the print execution unit includes: a print head having a plurality of nozzle groups corresponding to a plurality of color material and arranged in a main scanning direction, each of the plurality of nozzle groups comprising a plurality of nozzles arranged in a sub-scanning direction, each of the plurality of nozzles being configured to eject a droplet of color material onto a printing medium, the image processing apparatus comprising a controller configured to perform: acquiring image data; determining an ejection execution direction of the print head for each of a plurality of pieces of band image data, the image data including the plurality of pieces of band image data representing a plurality of band images arranged in the sub-scanning direction, the ejection execution direction being one of a first direction and a second direction, the first direction being parallel to the main scanning direction, the second direction being parallel to the main scanning direction and opposite to the first direction; and controlling the print execution unit to form an image according to the image data, the print execution unit repeatedly performing an ejection processing of ejecting the droplet of color material onto the printing medium and conveying the printing medium in the sub-scanning direction, an N-th ejection processing forming an N-th band image of the plurality of band images according to N-th band image data of the plurality of pieces of band image data, the N-th ejection processing being performed by moving the print head in the ejection execution direction successively after an (N−1)-th ejection processing is performed, wherein the controller is further configured to perform: specifying an estimate value for a target partial image by using color gap information, the target partial image being selected among a plurality of partial images included in the N-th band image, the color gap information including adjacent-state color gap information and separate-state color gap information, the adjacent-state color gap information being relevant to a color gap perceived when a first printed image and a second printed image are disposed adjacent to each other, the first printed image having a pixel value and being printed by moving the print head in the first direction, the second printed image having the pixel value same as the first printed image and being printed by moving the print head in the second direction, the separate-state color gap information being relevant to a color gap perceived when the first printed image and the second printed image are separated from each other, the adjacent-state color gap information being used in response to determining that the target partial image is adjacent to another band image different from the N-th band image, the separate-state color gap information being used in response to determining that the target partial image is not adjacent to another band image different from the N-th band image; determining whether the estimate value satisfies an estimate condition, the estimate condition indicating that a color gap between the first printed image and the second printed image is recognizable; determining the ejection execution direction with respect to the N-th ejection processing to be the first direction in response to determining that the estimate value satisfies the estimate condition; and determining the ejection execution direction with respect to the N-th ejection processing to be opposite to the ejection execution direction with respect to the (N−1)-th ejection processing in response to determining that the estimate value does not satisfy the estimate condition, where N is an integer equal to or greater than 2.