Integer multiwavelet transform for lossless image coding
The integer Haar wavelet transform or S-transform is used as the basic building block for many integer wavelet transforms. As an alternative, a new integer multiwavelet transform and its associated integer prefilter are designed based on a box-and-slope multi-scaling system. Both the transform and prefilter can be implemented with a simple integer Haar transform requiring only addition and bit shift operations. Since the new integer transform is an approximation to a nontrucated transform with a higher vanishing moment than that of a Haar transform, better approximation accuracy is expected and verified experimentally. The transform is successfully applied to lossless image coding with results outperforming that of lossless JPEG and S-transform.