A first distortion correction unit generates one first output pixel based on two input pixels that are adjacent in a first direction out of a plurality of input pixels included in image data pieces of a captured frame. A second distortion correction unit generates one second output pixel based on two first output pixels that are adjacent in a second direction different from the first direction. The second distortion correction unit successively reads two first output pixels adjacent in the second direction from a storage unit based on input coordinates, which correspond to coordinate values of second output pixels, and generates the one second output pixel by applying linear interpolation processing to the read two first output pixels based on interpolation coefficient.