DIGITAL IMAGE SIGNAL CODER AND ITS METHOD AND CODING IMAGE SIGNAL DECODER AND ITS METHOD

摘要

PROBLEM TO BE SOLVED: To reduce deterioration in image quality by comparing and selecting a prediction residue based on motion compensation and prediction residue based on hierarchy image processing. SOLUTION: A motion compensation prediction section 2 uses current frame data and preceding frame data to detect a motion vector MV and compensated image data Pt are formed by moving the preceding frame data based on the vector MV and the section 2 calculates prediction residue data Rt based on a difference between it and a true value. A spatial hierarchy direction prediction section 3 uses the input image data as a lower layer data and conducts arithmetic operation of calculating a mean value to form higher layer image data D2 to obtain a prediction picture element value Ps of the lower layer based on the data D2 and calculates prediction residue data Rs based on a difference between the D2 and a true value. A selection circuit 15 selects smaller data among plural blocked comparison data consisting of collection of Rt, Rs.