Multiwavelet Transform based Image Compression using Modified SPIHT Compression Scheme

摘要

In the present work a new implementation of multiwavelet transform, which is combined with modified Set Partitioning in Hierarchical Tree (SPIHT) compression scheme has been introduced. The SPIHT provides even better performance than Embedded Zero tree Wavelet (EZW). EZW coding introduced by J.M.Shapiro, is a very effective and computationally simple technique for image compression. Here an alternative explanation of the principles of its operation has been given, so that the reasons for its excellent performance can be better understood. These principles are partial ordering by magnitude with a set partitioning sorting algorithm, ordered bit plane transmission, and exploitation of self similarity across different scales of an image multiwavelet transforms. We provide the analysis of the problems arising from the application of zero tree quantization based algorithms, such as SPIHT to multiwavelet transform coefficients. We established the generalized parent-child relationships for multiwavelet, providing complete tree structure for SPIHT. The results obtained with the combination of multiwavelet transforms and the SPIHT compression scheme are much better than EZW and wavelet transform based image compression.