Patent US 6,038,345

An image processing apparatus includes an input unit for inputting image data having undergone orthogonal transformation, a generation unit for generating interframe difference image data, of adjacent frames with respect to the image data input by the input unit, using orthogonal transform coefficients, and an encoding unit for encoding the image data output from the generation unit. An image processing apparatus includes an input unit for inputting encoded data obtained by performing block encoding of interframe difference data using orthogonal transformation, a decoding unit for decoding the encoded data input by the input unit into orthogonal transform coefficient difference data, and an addition unit for adding the orthogonal transform coefficient data of a block different from a processed block to the difference data decoded by the decoding unit.