A dark color (for example, cyan) ink dot formed by preliminary ejection can be made less noticeable, and the influence on the printing quality can be reduced, even in a case where the dark color ink is preliminarily ejected onto a light color (for example, yellow) image area. For this purpose, in a case where the dark color ink is preliminarily ejected onto the image area of high lightness, the amount of the ink applied for printing the area is reduced. For example, in a case where a cyan ink is preliminarily ejected onto an area to be formed of yellow dots, a piece of data for forming the yellow dot in the preliminary ejection position is deleted. This reduces an overlapping area of the yellow area and the ink dot formed by the preliminary ejection, and thus makes the ink dot formed by the preliminary ejection less noticeable.