各类滤波器的MATLAB程序清单.doc

各类滤波器的MATLAB程序一、 理想低通滤波器IA=imread(lena.bmp);f1,f2=freqspace(size(IA),meshgrid);Hd=ones(size(IA);r=sqrt(f1.2+f2.2);Hd(r0.2)=0;Y=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 二、理想高通滤波器IA=imread(lena.bmp);f1,f2=freqspace(size(IA),meshgrid);Hd=ones(size(IA);r=sqrt(f1.2+f2.2);Hd(r0.2)=0;Y=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 三、 Butterworth低通滤波器IA=imread(lena.bmp);f1,f2=freqspace(size(IA),meshgrid);D=0.3;r=f1.2+f2.2;n=4;for i=1:size(IA,1) for j=1:size(IA,2) t=r(i,j)/(D*D); Hd(i,j)=1/(tn+1); endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 四、 Butterworth高通滤波器IA=imread(lena.bmp);f1,f2=freqspace(size(IA),meshgrid);D=0.3;r=f1.2+f2.2;n=4;for i=1:size(IA,1) for j=1:size(IA,2) t=(D*D)/r(i,j); Hd(i,j)=1/(tn+1); endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 五、 高斯低通滤波器IA=imread(lena.bmp);IB=imread(babarra.bmp);f1,f2=freqspace(size(IA),meshgrid);D=100/size(IA,1);r=f1.2+f2.2;Hd=ones(size(IA);for i=1:size(IA,1) for j=1:size(IA,2) t=r(i,j)/(D*D); Hd(i,j)=exp(-t); endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 六、 高斯高通滤波器IA=imread(lena.bmp);IB=imread(babarra.bmp);f1,f2=freqspace(size(IA),meshgrid);%D=100/size(IA,1);D=0.3;r=f1.2+f2.2;for i=1:size(IA,1) for j=1:size(IA,2) t=r(i,j)/(D*D); Hd(i,j)=1-exp(-t); endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 七、 梯形低通滤波器IA=imread(lena.bmp);IB=imread(babarra.bmp);f1,f2=freqspace(size(IA),meshgrid);%D=100/size(IA,1);D0=0.1;D1=0.4;r=sqrt(f1.2+f2.2);Hd=zeros(size(IA);Hd(r=D0 & r(i,j)=D1 Hd(i,j)=(D1-r(i,j)/(D1-D0); end endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 八、 梯形高通滤波器IA=imread(lena.bmp);IB=imread(babarra.bmp);f1,f2=freqspace(size(IA),meshgrid);%D=100/size(IA,1);D0=0.1;D1=0.4;r=sqrt(f1.2+f2.2);Hd=ones(size(IA);Hd(r=D0 & r(i,j)=D1 Hd(i,j)=(D0-r(i,j)/(D0-D1); end endendY=fft2(double(IA);Y=fftshift(Y);Ya=Y.*Hd;Ya=ifftshift(Ya);Ia=real(ifft2(Ya);figuresubplot(2,2,1),imshow(uint8(IA);subplot(2,2,2),imshow(uint8(Ia);figuresurf(Hd,Facecolor,interp,Edgecolor,none,Facelighting,phong); 九、 用其他方法编写的理想低通、理想高通、Butterworth低通、同态滤波程序1、 理想低通i1=imread(lena.bmp);i2=imnoise(i1,salt & pepper,0.1);f=double(i2);k=fft2(f);g=fftshift(k);N1,N2=size(g);d0=50;u0=floor(N1/2)+1;v0=floor(N2/2)+1;for i=1:N1 for j=1:N2 d=sqrt(i-u0)2+(j-v0)2); if d=d0 h=1; else h=0; end y(i,j)=g(i,j)*h; endendy=ifftshift(y);E1=ifft2(y);E2=real(E1);figuresubplot(2,2,1),imshow(uint8(i1);subplot(2,2,2),imshow(uint8(i2);subplot(2,2,3),imshow(uint8(E2); 2、 理想高通i1=imread(lena.bmp);i2=imnoise(i1,salt & pepper,0.1);f=double(i2);k=fft2(f);g=fftshift(k);N1,N2=size(g);n=2;d0=10;u0=floor(N1/2)+1;v0=floor(N2/2)+1;for i=1:N1 for j=1:N2 d=sqrt(i-u0)2+(j-v0)2); if d=d0 h=0; else h=1; end y(i,j)=g(i,j)*h;endendy=ifftshift(y);E1=ifft2(y);E2=real(E1);figuresubplot(2,2,1),imshow(uint8(i1);subplot(2,2,2),imshow(uint8(i2);subplot(2,2,3),imshow(uint8(E2); 3、 Butterworth低通i1=imread(lena.bmp);i2=imnoise(i1,salt & pepper,0.1);f=double(i2);k=fft2(f);g=fftshift(k);N1,N2=size(g);n=2;d0=50;u0=floor(N1/2)+1;v0=floor(N2/2)+1;for i=1:N1 for j=1:N2 d=sqrt(i-u0)2+(j-v0)2); h=1/(1+(d/d0)(2*n); y(i,j)=g(i,j)*h; endendy=ifftshift(y);E1=ifft2(y);E2=real(E1); figuresubplot(2,2,1),imshow(uint8(i1);subplot(2,2,2),imshow(uint8(i2);subplot(2,2,3),imshow(uint8(E2); 4、 同态滤波I=rgb2gray(imread(fabric00.bmp);M,N=size(I);T=double(I);L=log(T)