Patent ID: 8303069

Claim:
An image processing method for, in order to print to a printing region on a printing medium by scanning a first row of nozzles for ejecting chromatic ink and a second row of nozzles for ejecting achromatic ink in a scanning direction, processing data corresponding to an image to be printed to the printing area, the method comprising: a determination step of determining, based on data corresponding to the printing region, for each unit region obtained by dividing the printing region in a direction intersecting the scanning direction, whether the unit region is a first region where printing is to be performed using at least chromatic ink, a second region where printing is to be performed using only achromatic ink, or a third region where printing is not to be performed using chromatic ink or achromatic ink; and a changing step of, when there exists both a unit region that has been determined to be the first region and a unit region that has been determined to be the second region between unit regions that have been determined to be the third region, changing the determination results of the unit region that has been determined to be the second region to the first region.