An image processing apparatus including: a decoder; an image size processor that executes image processing regarding an image size on uncompressed image data as the output from the decoder; a general-use interface that transfers the output from the decoder or the image size processor; an exclusive-use interface that transfers the output from the decoder or the image size processor an image synthesis processor that generates uncompressed image data of a composite image for display of a small image size by image synthesis on the basis of uncompressed image data transferred through the exclusive-use interface, and generates uncompressed image data of a composite image for printing or storage of a large image size by image synthesis on the basis of uncompressed image data transferred through the general-use or the exclusive-use interface; and an encoder that compresses uncompressed image data of the generated composite image for printing or storage.