Patent ID: 8157343

Claim:
A printing apparatus for printing an image on a predetermined area of a print medium by plural printing scans of an ink jet printing head having at least a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third nozzle group for forming a third type of dot, relative to the predetermined area, said apparatus comprising: a first dividing unit configured to divide image data to be printed on the predetermined area by the first nozzle group into a plurality of image data used for the plural printing scans, by using a plurality of first mask patterns corresponding to the plural printing scans; a second dividing unit configured to divide image data to be printed on the predetermined area by the second nozzle group into a plurality of image data used for the plural printing scans, by using a plurality of second mask patterns corresponding to the plural printing scans; and a third dividing unit configured to divide image data to be printed on the predetermined area by the third nozzle group into a plurality of image data used for the plural printing scans, by using a plurality of third mask patterns corresponding to the plural printing scans, wherein respective arrangement patterns of print permitting pixels in a predetermined first mask pattern of the plurality of first mask patterns, a predetermined second mask pattern of the plurality of second mask patterns, and a predetermined third mask pattern of the plurality of third mask patterns, which are used for a predetermined printing scan of the plural printing scans are different from each other, and an amount of low frequency components of an arrangement pattern of print permitting pixels obtained by a logical product of the predetermined first mask pattern, the predetermined second mask pattern and the predetermined third mask pattern based on a correspondence relationship of the three mask patterns when the three mask patterns are used for printing is less than an amount of low frequency components of an arrangement pattern of print permitting pixels obtained by a logical product of the predetermined first mask pattern, the predetermined second mask pattern and the predetermined third mask pattern based on a correspondence relationship different from the correspondence relationship of the three mask patterns when the three mask patterns are used for printing.