Picture decoding method and decoding device

An image decoding method for decoding a bit stream of an encoded image signal comprising a header stream (Str_H) and a frame stream (Str_F), the header stream (Str_H) comprising a frame header stream and a segment header stream, the frame header stream including frame header information that is common information of a full image signal corresponding to frame data comprising a plurality of segments, the segment header stream including segment header information that is common information of a full image signal corresponding to each segment comprising a plurality of macroblocks, and the frame stream (Str_F) including frame information that is a full image signal corresponding to the frame data comprising the plurality of segments, wherein the image decoding procedure comprises: a demultiplexing step of receiving the encoded image signal bit stream and demultiplexing the encoded image signal bit stream into a frame header stream that includes frame header information, a segment header stream that includes segment header information and a frame flow that includes frame information; a stage of decoding the header information of: (1) receive the frame header stream and perform fixed-length decoding or variable-length decoding on the frame header information included in the frame header stream, in order to output a code value signal frame header corresponding to each of the frame header parameters, and (2) receiving the segment header stream and performing a fixed-length decoding or a variable-length decoding on the segment header information included in the segment header stream, in order to output a value signal of segment header code corresponding to each of a segment header parameters; and a frame information decoding step of receiving the frame stream and performing only one arithmetic decoding on the frame information, in a per macroblock fashion, with reference to the segment header parameter, in order to output a signal of frame code value corresponding to each macroblock and to reconstruct all decoded macroblocks of each segment included in the frame data, wherein the header information decoding step further includes a selecting step of selecting one of a fixed-length decoding procedure or a variable-length decoding procedure according to a syntax structure signal (Stx_H), and wherein the header information decoding step further includes: (1) decoding the frame header code value signal corresponding to the fixed-length code, using one of a plurality of fixed-length decoding procedures in accordance with the syntax structure signal of the code value signal of frame header, when the fixed-length decoding procedure is selected in the selection step, and (2) decoding the frame header code value signal corresponding to a variable length code, using one of a plurality of variable length decoding procedures in accordance with the syntax structure signal of the value signal of frame header code, when the variable-length decoding procedure is selected in the selection step, and (3) decoding the segment header code value signal corresponding to the fixed-length code, using one of a plurality of fixed-length decoding procedures in accordance with the syntax structure signal of the code value signal. segment header, when the fixed-length decoding procedure is selected in the selection step, and (4) decoding the segment header code value signal corresponding to a variable length code, using one of a plurality of variable length decoding procedures in accordance with the signal value signal syntax structure of segment header code, when the variable-length decoding procedure is selected in the selection step.