1. A picture processing device capable of performing a process of superposing a sub picture image on a moving picture image which forms a base, comprising: a detection unit for detecting a region in which a movement amount is small, out of a plurality of regions in which the sub picture image may be superposed on the moving picture image which forms a base; and a picture image superposing unit for superposing the sub picture image on the region in which the movement amount is small, the region being detected by the detection unit.