Image Compression Method Based on Bioorthogonal Invariant Set Multiwavelet

Abstract

The invention discloses an image compression method based on biorthogonal invariant set multi-wavelets, the steps of which are: 1. input image data; 2. DC level shift; 3. composition of filter matrix judgment; Variable set multi-wavelet transform layer initialization; 5. Extend the height and width of the image; 6. Biorthogonal invariant set multi-wavelet row transform; 7. Biorthogonal invariant set multi-wavelet column transform; 8. Quantization coefficients; 9 . Arithmetic coding; 10. Rate-distortion optimized interception; 11. Code stream organization. The present invention adopts a group of biorthogonal invariant set multi-wavelet filters with symmetry, compact support and orthogonality, and adopts the method of inner product in calculation of biorthogonal invariant set multi-wavelet transform, so that the complexity of the algorithm is greatly reduced , the high concentration of energy and entropy after transformation has greater sparsity, which is beneficial to subsequent compression coding, and it is convenient for block processing and parallel acceleration.

Description

technical field [0001] The invention relates to the technical field of image processing, and further relates to an image compression method based on biorthogonal invariant set multi-wavelets implemented in a JPEG2000 image compression system in the technical field of image compression. The present invention can be used for compression coding of various digital still images. Background technique [0002] With the development and application of multimedia and network technology, traditional image compression algorithms can no longer meet the requirements of practical applications. Therefore, the International Standard Organization formulated a new standard JPEG2000 for still image compression in November 2000. The new standard adopts the rate-distortion optimized truncation embedded code block coding algorithm (EBCOT) based on wavelet transform technology, and has achieved better image compression effect. But the JPEG2000 system needs two systems of fixed point and floating p...

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Problems solved by technology

However, the disadvantage of this patented technology is that since the 5 / 3 wavelet and 9 / 7 wavelet used in this patented technology are both single wavelets, each layer of wavelet transform can only obtain features in 4 different directions, and the energy after wavelet transform The degree of concentration and entropy is not high, and the wavelet transform needs to extend the boundary of the image to cause boundary distortion, which is not conducive to block processing and parallel acceleration

Although this method has achieved a certain compression effect, the disadvantage of this method is that this method only gives a simple multi-wavelet basis of 2 by 2, and it is difficult to reflect the symmetry, short-term Support, orthogonality and high-order vanishing moment properties, and the computational complexity of the compression coding algorithm has not improved and is equivalent to JPEG2000

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