An image recording apparatus records an image on a printing plate wound around a rotating drum with a light beam emitted from an exposure head. In the image recording apparatus, an actual drum rotational speed Nx is recognized, and the image is recorded on the printing plate in an accelerating period in which the actual drum rotational speed Nx is equal to or higher than a predetermined rotational speed, a constant-rotational-speed period, and a decelerating period. An exposure beam position, an exposure beam output, and an auxiliary scanning speed of the exposure head are corrected dependent on the peripheral speed of the drum in the accelerating period and the decelerating period.