A method and apparatus for data compression based on wavelets

摘要

A motion wavelet transform zero tree codec achieves high compression and is implemented in hardware of modest size and at very low cost. A wavelet transform (200) is combined with a tree walk technique (500) for encoding the resulting wavelet coefficients (802-816). A 2-6 wavelet transform is used (700). Wavelet coefficients (802-816) from the transform are represented in a pyramid (600) of wavelet coefficients. An array of zero trees (820) are formed from the pyramid (600) to hold the wavelet coefficients, one coefficient to each node. Significance values (854-858) for each node are calculated to assist with the tree walk and encoding. Each zero tree (820) is traversed to produce an output of encoded bits. Encoded bits are output directly during the tree walk.