IMAGE ENCODING APPARATUS AND MOVING PICTURE ENCODING APPARATUS UTILIZING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an image encoding apparatus for eliminating the reduction in an encoding efficiency in a lower-order plane in the case of applying bit plane encoding to an image signal coefficient so as to enhance the decoded image quality characteristics in the midway stage. SOLUTION: A significant/refinement bit separate section 3 classifies each bit expressed in a bit plane by an encoding pre-processing section 2 into two kinds; a significant bit group and a refinement bit group depending on a degree of the bit to enhance the image quality. A significant bit encoding section 4 applies e.g. variable length encoding to the significant bit group. A refinement bit encoding section 7 encodes a bit with a highest contribution of enhancing the image quality with priority in the refinement bit group not yet encoded as the encoding sequence. A composite processing section 8 composes the encoded significant bits, refinement bits and encoded bits and outputs the result as encoded data. COPYRIGHT: (C)2003,JPO