A color blindness dialog box in a Properties window includes a color blindness process mode checkbox enabling a user to select a printing process designed for color blindness. When the color blindness process mode checkbox is checked, it is determined whether the image to be printed includes problematic areas for people with color blindness. If so, image data for these areas is extracted and displayed in a popup window. Subsequently, a borderline process is performed to form a borderline on either or both of the border areas and of text data and graphics data. Thus, the problematic areas are extracted and processed properly so that the problematic areas will become easy to distinguish.