An image processing apparatus includes: a first inverter to output binary image data having first resolution, as image data having pixel values that are inverted or image data having unprocessed pixel values, in accordance with an inversion signal; a thinning processor to convert the image data output from the first inverter from the first resolution to second resolution and perform a thinning process of thinning pixels of edge portions of the image data in units of the second resolution; and a second inverter to output the image data having the second resolution for which the thinning process is performed, as image data having pixel values that are inverted or image data having unprocessed pixel values, in accordance with the inversion signal.