An image forming apparatus includes a reading table, an image reading device, an image forming device with an exposure device, and circuitry. The reading device reads a pattern on a recording medium on the table, and generates image data of the pattern. The exposure device includes a light emitting element to form an electrostatic latent image, based on which the image forming device forms the pattern. Based on first and second correction values, the circuitry calculates a third correction value to correct a light amount of the light emitting element. The exposure device includes a driving device that drives the light emitting element based on the third correction value. The circuitry sets at least two or more determination areas in each of a white area and a pattern area of the medium, and determines whether the medium has a rise based on density data in the determination areas.