1. An image processing device, comprising: a generating unit, which generates additional information including information to specify a color image or a depth image, conversion information, which indicates an area of an image included in the depth image, a resolution of which is converted to the same resolution as the resolution of the color image, and resolution information to distinguish whether the resolution of the color image and the resolution of the depth image are different from each other; and a transmitting unit, which transmits the color image, the depth image, and the additional information generated by the generating unit.