An image forming apparatus includes an illumination device, a beam splitter, an imaging device, and an image forming circuit. The illumination device includes first emitters emitting first light polarized at 30°, second emitters emitting second light polarized at 90°, and third emitters emitting third light polarized at 150°, and illuminates a subject with the first, second, and/or third light. The beam splitter splits returning light and outputs a first component polarized at 0°, a second component polarized at 60°, and a third component polarized at 120°. The imaging device has an imaging surface that includes a first region receiving the first component, a second region receiving the second component, and a third region receiving the third component. The image forming circuit generates an image of the subject based on first, second, and third groups of images acquired when the subject is illuminated with the first, second, and third light.