An image processing apparatus for converting a color image into an image of an N (N=2, 3, . . . ) number of colors, i.e., black and other colors, is disclosed. In the image processing apparatus, a gray-component extracting unit extracts a gray component signal from input color image signals, and produces remaining-color-component signals. A black signal generating unit generates a black signal by using the gray component signal and the remaining-color-component signals. A color signal generating unit generates a color signal by using the remaining-color-component signals. The image processing apparatus may further include first print signal generating means for developing a black signal outputted from the black signal generating means into a black dot pattern, second print signal generating means for developing a color signal outputted from the color signal generating means into a color dot pattern, and adjust means for adjusting the print signals outputted from the first and the second print signal generating means so that when a black dot of the black dot pattern and a color dot of the color dot pattern occupy the same dot position, one of the black and the color dots is preferentially used for print.