www.gusucode.com > wavelet工具箱matlab源码程序 > wavelet/wavelet/orthfilt.m
function [Lo_D,Hi_D,Lo_R,Hi_R] = orthfilt(W,P) %ORTHFILT Orthogonal wavelet filter set. % [LO_D,HI_D,LO_R,HI_R] = ORTHFILT(W) computes the % four filters associated with the scaling filter W % corresponding to a wavelet: % LO_D = decomposition low-pass filter % HI_D = decomposition high-pass filter % LO_R = reconstruction low-pass filter % HI_R = reconstruction high-pass filter. % % See also BIORFILT, QMF, WFILTERS. % M. Misiti, Y. Misiti, G. Oppenheim, J.M. Poggi 12-Mar-96. % Last Revision: 13-May-2003. % Copyright 1995-2004 The MathWorks, Inc. % Check arguments. if nargin<2 , P = 0; end % Normalize filter sum. W = W/sum(W); % Associated filters. Lo_R = sqrt(2)*W; Hi_R = qmf(Lo_R,P); Hi_D = wrev(Hi_R); Lo_D = wrev(Lo_R);