An image processing apparatus prints an image without streaks on a medium. A receiving section receives base color image data and non-base color image data. A detecting section detects a boundary between a first area in which the base color image is printed and a second area which surrounds the first area and no image is printed therein. A correction section performs correction on the image data to generate one of a third area defined in a peripheral portion of the first area and a fourth area which is defined in a peripheral portion of the second area and is contiguous to the first area. A smaller amount of base color toner is consumed in the third and fourth area than in the first area. A printing section prints an image on a medium in accordance with the corrected base color image data and the non-base color image data.