To provide a processing apparatus for performing synthesis of video data to which video data of optically overlapped (duplicated overlap) video images are imparted. An image processor includes gamma removal units 810, 811, and 812 which remove gamma processing performed on video data to which video data of optically overlapped (duplicated overlap) video images are imparted, a video synthesis unit 825 which synthesizes video data adjacent to each other in the video data from which the gamma processing is removed, and a gamma addition unit 826 which re-performs gamma processing on the synthesized video data.