Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!news.funet.fi!news From: varri@news.funet.fi.tut.fi (V{rri Alpo) Newsgroups: comp.dsp Subject: Re: Complementary filters Message-ID: <1990Dec8.094311.11191@funet.fi> Date: 8 Dec 90 09:43:11 GMT References: Sender: news@funet.fi (#News ) Organization: Finnish University and Research Network FUNET Lines: 15 >>>Is there a recipe for generating the "complement" of a given filter? Or >>>for generating a pair of filters which are complementary in this sense? > >>Generate one of the too signals, e.g. the low passed signal. Subtract it >>from the original signal to get the high passed signal. > > This is a nice idea, but it won't work in general. > i.e. simple subtraction doesn't consider the phase response of H(z). > Something must have been written on this, what about Quadrature Mirror > Filterbanks ?? You could try this one: Tree-Structured Complementary Filter Banks Using All-Pass Sections, Regalia P, Mitra S, Vaidyanathan P, Renfors M, Neuvo Y. IEEE Transactions on Circuits and Systems, Vol. CAS-34, No. 12, Dec. 1987.