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filter design

Started by elham askari February 21, 2010
hi dears
Ihave designed a chebyshev 1 filter bymatlab by impulse invariance method with these below codes
now I want to perform this filter on an image and see the result effect on this image, so how can do this? with which code in matlab??please help me.

% Chebyshev type I polynomials, Impulse Invariance, Method 1
clear all; close all;clc;
wp=.2*pi,ws=.3*pi,dp=1,ds,Fs=1;
[n,wc]=cheb1ord(wp,ws,dp,ds);
%n = 4;
[z,p,k]=cheb1ap(4,dp);
Wc=Fs*(wc);% Prewarping
[bs,as] = zp2tf(z,p,k);%Convert zero-pole-gain filter parameters to transfer function form
[bst,ast] = lp2lp(bs,as,Wc);%Change cutoff frequency for lowpass analog filter
[b1,a1] = impinvar(bst,ast,Fs);
[H1,w] = freqz(b1,a1);