The efficiency of the image subband coding algorithms based on zerotrees

EZW (Embedded image coding using Zerotrees of Wavelet coef?cients) and SPIHT (Set Partitioning in Hierarchical Trees) are two of the best known progressive coding algorithms for the subbands of images. A progressive image-coding algorithm has to include at each pass, information about the magnitude of the significant coefficients, and their position in the two-dimensional array of the transform. This article evaluates the efficiency of those algorithms, expressed through the compactness of the position information.