A wavelet transform image coding technique with a quadtree structure

Much work in image coding has centered on wavelet transforms, which can be used to generate multiresolution representation of images. Wavelet transforms have been shown to achieve high compression ratios while maintaining very good image quality, because edge characteristics of images can be well preserved by this method at low bit rates. Quadtree decomposition techniques also utilize the multiresolution nature of images of a segmentation device before coding. The implementation of a novel hybrid technique for coding the coefficients of a wavelet transformation which makes use of a quadtree structure is discussed. This method is a scalar coding technique which takes advantage of the correlation between different scales in the wavelet decomposition, while requiring much less computational complexity than a comparable full search vector quantization technique described.<>