Patent ID: 8743420

Claim:
An image processor for printing an image on a first area of a printing medium by using a first nozzle group including part of nozzles in a first nozzle array in which a plurality of first nozzles for ejecting a first ink are arranged and by using a second nozzle group including part of nozzles in a second nozzle array in which a plurality of second nozzles for ejecting a second ink are arranged, and for printing an image on a second area different from the first area of the printing medium by using a third nozzle group including a nozzle different from the nozzle of the first nozzle group in the first nozzle array and by using a fourth nozzle group including a nozzle different from the nozzle of the second nozzle group in the second nozzle array, the image processor comprising: a first conversion unit configured to convert a plurality of color signals in input data of an image to be printed on the first area into a plurality of color signals including a color signal corresponding to the first ink and a color signal corresponding to the second ink, and to convert a plurality of color signals in input data of an image to be printed on the second area into a plurality of color signals including a color signal corresponding to the first ink and a color signal corresponding to the second ink, such that a difference between a color of an image printed by using the first nozzle group and the second nozzle group in the case where a predetermined plurality of color signals are input and a color of an image printed by using the third nozzle group and the fourth nozzle group in the case where the predetermined plurality of color signals are input is reduced, a second conversion unit configured to convert a color signal, converted by the first conversion unit, corresponding to the first ink to be printed on the first area and a color signal, converted by the first conversion unit, corresponding to the first ink to be printed on the second area, such that a difference between a density of an image printed on the first area by ejecting the first ink only from the first nozzle group in the case where a predetermined first color signal is input and a density of an image printed on the second area by ejecting the first ink only from the third nozzle group in the case where the predetermined first color signal is input is reduced, and to convert a color signal, converted by the first conversion unit, corresponding to the second ink to be printed on the first area and a color signal, converted by the first conversion unit, corresponding to the second ink to be printed on the second area, such that a difference between a density of an image printed on the first area by ejecting the second ink only from the second nozzle group in the case where a predetermined second color signal is input and a density of an image printed on the second area by ejecting the second ink only from the fourth nozzle group in the case where the predetermined second color signal is input is reduced.