Among pickup image data items of multiple frames picked up at different time instants, an image of a certain frame is regarded as a synthesizing base image. The synthesizing base image and an image of another frame are used to perform synthesizing processing. Specifically, an object-of-synthesis area is designated in the frame image regarded as the synthesizing base image, and processing of replacing pixel data in the object-of-synthesis area with pixel data in another frame is carried out. For example, if a person having his/her eyes closed appears in the synthesizing base image that is a group-photograph image, the part of the person's face is regarded as the object-of-synthesis area. As another frame, an image in which the person has his/her eyes left open is searched. Pixel data in the facial image part showing the open eyes is fetched and synthesized with the synthesizing base image. Thus, a group photograph in which all people have their eyes left open is produced.