Modified embedded zerotree wavelet algorithm for fast implementation of wavelet image codec

Embedded zerotree wavelet (EZW) coding, proposed by Shapiro, is one of the commonly used algorithms for wavelet image coding. The speeds of coding and decoding are important issues in the implementation of an image codec. The algorithm proposed by Shapiro requires large execution times due to the numerous comparisons involved. This algorithm is modified to improve the speeds of the encoder and the decoder without otherwise affecting the performance. The modification results in faster software implementation and much laster implementation on a hardware-like platform (tested here using a DSP).