关键词: 小波编码, 数学形态学, 膨胀, 差分缩减

Abstract:

A novel wavelet image coder is proposed according to both cluster characteristic of intra-subband significant wavelet coefficients and inter-subband similarity. The algorithm utilizes two different structuring elements for morphological dilation to extract and encode the subband clustered significant coefficients, and it can solve the conflict between dilation speed and dilation quality when using the single structuring element. The difference reduction is used to encode the position of start position in each cluster and sparse coefficients, which can improve the coding efficiency of the insignificant coefficients. Furthermore, the algorithm uses the parent-children relationship to reduce the correlation between wavelet coefficients across subbands, while elaborately designed adaptive arithmetic coding can further reduce code redundancy. As a kind of embedded coder, the algorithm is also rate scalable. Experimental results show that the performance of the new coder is superior to the SPIHT and EBCOT, and outperforms the non-embedded morphology coders MRWD and SLCCA.

Key words: wavelet-based coding, mathematical morphology, dilation, difference reduction