Wavelet-based image compression by adaptive scanning of transform coefficients

An image compression algorithm exploiting the interband and intraband dependencies in a multiresolution decomposition structure is introduced. The transform coefficients, other than those which belong to the direct current band, are adaptively scanned into two different one-dimensional arrays. These arrays are generated by using the observed statistical behavior of wavelet transform coefficients, in an effort to maximize local stationarity. The arrays are then entropy coded separately by a recently introduced entropy coding method. The algorithm is also extended for the compression of wavelet packet transform coefficients, by proposing a new efficient way of defining the parent-children link for wavelet packet decomposition. Experimental results indicate that the algorithms have competitive performance. (C) 2002 SPIE and IST.