A digital camera has a memory for storing a plurality of programs each to embed a watermark on a digital image data. The digital camera embeds the watermark on the image data according to the program selected by a program selector. In the case of a digital camera capable of selecting whether or not to embed a watermark, the digital camera forcibly controls to embed the watermark if the selection is failed. The digital camera has a processor for processing a digital image data in accordance with one of a plurality of selective data forms, one of the data forms being suitable for a watermark, and another unsuitable. In this case, the digital camera controls the processor to replace the unsuitable data form by the suitable one under the necessity of embedding the watermark on the digital image data.