[attachment=4968]
Modified SPIHT algorithm for wavelet packet image coding

Nikola Sprljana,
, Sonja Grgicb, Mislav Grgicb
aMultimedia and Vision Lab, Department of Electronic Engineering, Queen Mary, University of London, London E1 4NS, UK
bFaculty of Electrical Engineering and Computing, University of Zagreb, Unska 3/XII, HR-10000 Zagreb, Croatia

---

Abstract
This paper introduces a new implementation ofwavelet packet decomposition which is combined with SPIHT (Set Partitioning in
Hierarchical Trees) compression scheme. We provide the analysis ofthe problems arising from the application of zerotree
quantisation based algorithms (such as SPIHT) to wavelet packet transform coefficients. We established the generalized
parent–child relationships for wavelet packets, providing complete tree structures for SPIHT. The proposed algorithm can be used
for both wavelet dyadic and Wavelet Packet decomposition (WP-SPIHT). An extensive evaluation of the algorithm was performed
and it has been shown that WP-SPIHT significantly outperforms base-line SPIHT coder for texture images. For these images the
suboptimal WP cost-function enables good enough energy compaction that is efficiently exploited by the WP-SPIHT.
r 2005 Elsevier Ltd. All rights reserved.