1. An image processing device, comprising: one or more processors configured to: generate additional information that includes information to specify: a color image of a subject and a first depth image of the subject; conversion information that indicates a difference between a first number of pixels of a second depth image of the subject and a second number of pixels of the first depth image, wherein a first resolution of the second depth image is based on a second resolution of the first depth image, wherein the first resolution of the second depth image is same as a third resolution of the color image; and resolution information that indicates the third resolution of the color image and the second resolution of the first depth image; encode, based on the additional information, the color image and the second depth image to generate an encoded bit stream, wherein the encoded bit stream comprises the additional information as SEI (supplemental enhancement information) in the encoded bit stream; and transmit the encoded bit stream.