An image processing apparatus for generating a print image which can be easily visually recognizable under a particular light source, without using special ink, by utilizing a characteristic of a print medium. A color information holding unit holds first color information and second color information indicating different ink use amounts in a print unit per unit area on a print medium, and a color difference equal to or less than a predetermined value under ordinary light. In accordance with a value of a pixel of binary latent image data delivered from a latent image generator, a discrimination image data generator print-outputs one of the first color information and the second color information as print data with respect to the pixel.