An image processing apparatus includes a plurality of decoders, each decoding a predetermined region of each frame forming coded stream and an output unit receiving pixel data obtained as a result of the decoding processing by the plurality of decoders and combining the pixel data into decoded image data to output it. One subject decoder supplies, among pixel data obtained as a result of the decoding processing by the subject decoder, pixel data necessary for a different decoder to the different decoder, and also obtains, among pixel data obtained as a result of the decoding processing by the different decoder, pixel data necessary for the subject decoder from the different decoder. The subject decoder performs the decoding processing by referring to the pixel data obtained as a result of the decoding processing by the subject decoder and the pixel data obtained from the different decoder.