Adaptive variable-length coding and decoding methods for image data

摘要

An adaptive variable-length coding/decoding method performs an optimal variable-length coding and decoding depending on an intra mode/inter mode condition, quantization step size and a current zigzag scanning position within the block, such that a plurality of variable-length coding tables having different patterns of a regular region and an escape region according to statistical characteristics of the Ärun, levelÜ data are set. One of the variable-length coding tables is selected according to mode, quantization step size and scanning position within the block, and the orthogonal transform coefficients according to the selected variable-length coding table are variable-length coded. <IMAGE>