A movement vector calculation unit calculates, from a processing target frame in a motion picture and an immediately previous frame, a movement vector between the processing target frame and the immediately previous frame. An index value calculation unit calculates an index value indicating a degree of reliability of a movement from the processing target frame and the immediately previous frame. A correction unit corrects the movement vector using the index value to calculate a corrected movement vector, and a registration unit registers the immediately previous frame to the processing target frame on the basis of the corrected movement vector. A synthesis unit synthesizes the processing target frame and the registered immediately previous frame to generate a synthetic frame.