MULTIWAVELET PREFILTERS - I - ORTHOGONAL PREFILTERS PRESERVING APPROXIMATION ORDER P-LESS-THAN-OR-EQUAL-TO-2

In applications using multiwavelets, there is a necessary step of asso ciating a given discrete signal with a function in the scaling functio n space V-0. This association is equivalent to including a prefilter a nd a post-filter for the filter bank determined by the underlying mult iwavelets. We give a construction for orthogonal (paraunitary) finite- impulse esponse (FIR) prefilters that preserve the approximation order of a given arbitrary scaling vector Phi with approximation order p le ss than or equal to 2, We give several such prefilters for the DGHM mu ltiwavelet.