METHOD AND DEVICE FOR ENTROPY CODING FOR CLASSIFIED COEFFICIENT LEVEL

• Main Authors: SHEN MEI SHEN, TEIO KEN TAN
• Format: Patent
• Language: English
• Published: 23.01.1998
• Edition: 6
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To decrease an overall required bit number, with respect to a block by using information to decide a range of an event of a succeeding run level to be decoded. SOLUTION: An encoder uses a lock division section 2, to divide an input frame 1 into blocks each consisting of 8×8 pixels for processing. The obtained blocks are fed to a DC transformation section 5, in which they are subject to DC transformation. The DCT coefficients are fed to a quantization section 7, where they are quantized. The quantized levels are scanned by a zig-zag scanning section 9 as a series of events, consisting of a non-zero level and a plurality of zero levels succeeding thereto. When a block is discriminated to be a monotonic block, the block is encoded. When the block is a monotonic block, the block is coded by using a 1st entropy model. Then whether or not the entropy model is to be changed is decided, based on the event coded most recently.