JPEG2000 image coding method

Abstract

The invention discloses a JPEG2000 image coding method. Based on a JPEG2000 standard, Tier1 codes are improved, according to the characteristic that the minimum distortion slope of a first code block serves as an initial value of a threshold and is used for cycle judgment, a coding channel set in a '1' state is coded, and a coding channel set in a '0' state is abandoned. By means of cycle judgment, a large number of Tier1 redundant coding channels can be cut off, and the threshold value of the optimal distortion slope of Tier2 search and the range of optimal cut-off points are reduced, so that JPEG2000 image coding storage capacity and computing time can be remarkably reduced, and coding efficiency is improved. The method includes the steps: 1 original image preprocessing; 2 discrete wavelet transforming; 3 quantitative processing; 4 Tier1 coding; and 5 Tier2 coding.

Description

Technical field: [0001] The invention relates to the technical field of image processing, in particular to a JPEG2000 image coding method. Background technique: [0002] JPEG2000 is the latest international standard static image compression standard developed by the Joint Photographic Experts Group (JPEG). It has various outstanding features, making it widely used, especially in Internet transmission, wireless communication, digital cameras, medical images, etc. The field will have attractive application prospects. But the embedded block coding with optimized truncation (EBCOT) method adopted by JPEG2000 has a high complexity, which affects its practical application. EBCOT is composed of two parts, Tier1 code and Tier2 code. Tier1 encoding is entropy encoding of quantized sub-band coefficients, which accounts for about 45% to 60% of the calculation time of the JPEG2000 encoder. Reducing the calculation amount of Tier1 will greatly reduce the processing time of the encoding...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of a large number of redundant calculations and waste of storage resources in JPEG2000 image Tier1, and propose a JPEG2000 encoding method, which improves Tier1 encoding on the basis of the JPEG2000 standard, and according to the first encoding block The minimum rate-distortion slope of the threshold is used as the initial value of the threshold and the two characteristics of loop judgment. The encoding channel set to the "1" state is encoded, and the encoding channel set to the "0" state is discarded.

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