An image forming apparatus including a scanning unit, an image data synthesizing unit, and a printing unit is described. The scanning unit reads a first image, generates first image data representing the first image, reads a second image and generates second image data representing the second image. The image data synthesizing unit generates, on the basis of the first and second image data, synthesized image data representing a synthesized image of the first and second images arranged in a contact state where a first side which is one of four sides constituting an outer edge of the first image and a second side which is one of four sides constituting an outer edge of the second image are disposed immediately adjacent to each other or in a close state in which these sides are disposed parallel to and close to each other. The printing unit prints the synthesized image.