New prefilter design for discrete multiwavelet transforms

In this paper, we propose a new prefilter design that combines the ideas of the conventional wavelet transforms and multiwavelet transforms. The prefilters are orthogonal but nonmaximally decimated. They are derived from a very natural calculation of multiwavelet transform coefficients. In this new prefilter design, multiple step discrete multiwavelet decomposition is taken into account. Our numerical examples (by taking care of the redundant prefiltering) indicate that the energy compaction ratio with the Geronimo, Hardin and Massopust 2 wavelet transform and our new prefiltering is better than the one with Daubechies D₄ wavelet transform.