CODING METHOD AND CODING DEVICE OF OBJECT IMAGE, PARTICULARLY CONCERNED WITH MOVING A MACRO BLOCK FOR DIVIDING A VOP IN MPEG-4 TO AN INFORMATION REDUCTION POSITION IN ACCORDANCE WITH SHAPE INFORMATION OF AN OBJECT IMAGE, TO IMPROVE A CODING EFFICIENCY

摘要

PURPOSE: A coding method and a coding device of an object image are provided to move a macro block of a VOP(Video Object Plane) coding signal, where shape information is coded, to an information reduction position, and to perform motion estimation, motion compensation, and object internal coding processes, thereby improving a coding efficiency and reducing an amount of information. CONSTITUTION: A coding device defines a VOP formed in a VOP forming unit(S11). The device divides the VOP into macro blocks having certain pixels(S12). The device determines an information reduction position while moving a grid start point of the macro blocks(S13). The device codes shape information in a shape coding unit according to the information reduction position(S14). The device searches an information reduction position existing in a macro block having the smallest number of object images to output the position(S15). The device estimates a motion in macro block unit based on the outputted information reduction position, compensates for the motion, then performs a coding process(S16). The device outputs the coded shape information, motion information, and object internal information(S17).