METHOD AND APPARATUS FOR IMAGE ENCODING/DECODING USING EFFICIENT NON-FIXED QUANTIZATION

摘要

PURPOSE: A method and an apparatus for encoding/decoding an image using efficient non-fixed quantization are provided to control the size of the quantization according to the position of a frequency coefficient and to improve compression performance. CONSTITUTION: A converting unit produces a frequency conversion block(S810). The quantization unit selects a scanning method according to the mode information of a block determined by a prediction unit on the frequency conversion block(S820). While the quantization unit performs a determined scanning, it changes the size of the quantization on the frequency conversion block(S830). An encoding unit encodes the quantized frequency conversion block into a bit stream through an entropy coding(S840). [Reference numerals] (AA) Start; (BB) End; (S810) Generating a frequency conversion block by a converting unit(530); (S820) Selecting a scanning order according to the determined block mode information by a prediction unit(510) on the frequency conversion block; (S830) Determining the size of the quantization according to the determined scanning order; (S840) Generating a bit stream using a finished quantization factor