Cosine-modulated wavelets: new results on design of arbitrary length filters and optimization for image compression

This paper presents a procedure for designing cosine-modulated wavelet filters of arbitrary length applicable to image compression. Both criteria of frequency selectivity and of maximum coding gain are first considered in the design. In order to obtain cosine modulated bases of compactly supported M-band wavelets, additional regularity constraints are then imposed on the filters. The approach presented here allows to derive arbitrary length solutions with high stopband attenuation even in the presence of additional constraints such as regularity. The impact of the different parameters of the wavelet filters on the compression efficiency is evaluated. These filter solutions are also tested comparatively to wavelet packets in a subband coding scheme using lattice vector quantization optimized in the rate-distortion sense