An image indicating a copyright and its related information are set through a setting input means and those settings are stored in a related information storing means in advance. Registration image data is recorded in a detachable registration image data recording medium in advance. When an arbitrary image signal is generated by an image generating means, an image combining control means receives the generated image signal and also receives, via a registration image data input means, the registration image data stored in the registration image data recording medium. Further, the image combining control means generates a registration image signal by referring to the setting information and combines it with the arbitrary image signal. In this state, if no corresponding registration image data exists in the registration image data recording medium, image signal combining is not performed. A generated combined image signal is output from a combined image output means to a combined image recording medium or the like. Like the image combining control means, if no corresponding registration image data exists in the registration image data recording medium, the combined image output means does not perform output.