Embedded type zero-type encoding method and circuit structure thereof

Abstract

The invention relates to an embedded zero-tree coding mode and its circuit structure. It divides the embedded zero-tree coding into two processing stages, and simultaneously makes coding multiple bit planes in parallel. In the first-stage processing, firstly reading wavelet transform coefficients in a mode of scanning from low layer subband to high layer subband group by group, layer by layer and tree by tree; then executing multistage quantization for corresponding multiple threshold values; preprocessing the quantized data; after processing, independently coding the processed data on their respective bit planes; registering the symbols generated by data coding in an output buffer; after all the wavelet transform coefficients of a wavelet tree are allocated with symbols and stored into the output buffer, starting the second-stage processing; according to the scanning sequence from high layer subband to low layer subband, screening effective coded symbol output. It can raise coding rate, reduce coding time, has low requirements for IC performance and resources and is flexible to apply and easy to implement. It can be applied to the field of video data compression or image data compression.

Description

Technical field: [0001] The invention belongs to the field of video data compression or image data compression, and in particular relates to an embedded zero-tree coding method and a circuit structure thereof. Background technique: [0002] In video data compression and image data compression, mathematical transformation techniques are often used to improve compression performance. A frequently used mathematical transformation is wavelet transform. Figure 1 and Figure 2 are schematic diagrams of wavelet transform frequency bands, where L represents low frequency and H represents high frequency. Figure 1 is a 1-layer wavelet transform of an image, which produces 4 subbands. Figure 2 is a pyramid-shaped 4-layer wavelet transform of an image, which is a commonly used wavelet transform in the field of image compression. After the first layer of wavelet transform, the second layer of wavelet transform is performed on the low-frequency sub-band LL1, and then the third layer of w...

AI Technical Summary

Problems solved by technology

[0018] In addition, the embedded zero tree coding adopts successive quantization and coding methods, and the large coefficients need to be cleared and skipped after each quantization, so it is easier to perform serial bit-by-bit plane coding

However, the number of times of quantization is generally more than 10 bits, and the zero-tree coding of more than 10 bit planes must be serially executed, and an integrated circuit with a very high processing speed will have to be used for applications requiring fast data compression

Low-cost integrated circuits are difficult to implement

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