IEEE Transactions on Circuits and Systems for Video Technology Vol June A New Fast and E cient Image Codec Based on Set Partitioning in Hierarchical Trees

Embedded zerotree wavelet EZW coding introduced by J M Shapiro is a very e ective and computationally simple technique for image compression Here we o er an alternative explanation of the principles of its operation 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 di erent scales of an image wavelet transform Moreover we present a new and di erent implementation based on set partitioning in hierarchical trees SPIHT which provides even better performance than our previosly reported extension of the EZW that surpassed the performance of the original EZW The image coding results calculated from actual le sizes and images reconstructed by the decoding algorithm are either compara ble to or surpass previous results obtained through much more sophisticated and computationally complex methods In addition the new coding and decoding pro cedures are extremely fast and they can be made even faster with only small loss in performance by omitting entropy coding of the bit stream by arithmetic code