An image forming apparatus includes an image area identification unit to discriminate a character area and a line drawing area from an image area with respect to an image formed based on inputted color image data, an edge detection unit to detect an edge of a character and a line drawing, which is identified, and an edge γ correction unit to perform, only in a case where the edge exists on a white ground area in the image, thinning to lower an image density of a pixel on an outer border corresponding to the edge on the white ground area.