基于matlab數(shù)字圖像處理之高通濾波器

1、實踐二: 理想高通濾波器、Butterworth高通濾波器、高斯高通濾波器2.1.1 理想高通濾波器實踐代碼： I=imread('girl.bmp');subplot(221),imshow(I);title('原圖像');s=fftshift(fft2(I);subplot(223),imshow(abs(s),);title('圖像傅里葉變換所得頻譜');subplot(224),imshow(log(abs(s),);title('圖像傅里葉變換取對數(shù)所得頻譜');a,b=size(s);a0=round(a/2);b0=

2、round(b/2);d=10;p=0.2;q=0.5;for i=1:a for j=1:b distance=sqrt(i-a0)2+(j-b0)2); if distance<=d h=0; else h=1; end; s(i,j)=(p+q*h)*s(i,j); end;end;s=uint8(real(ifft2(ifftshift(s);subplot(222),imshow(s);title('高通濾波所得圖像');I=imread('girl.bmp');f1,f2=freqspace(size(I),'meshgrid'

3、);Hd=ones(size(I);r=sqrt(f1.2+f2.2);Hd(r<0.2)=0;figuresurf(Hd,'Facecolor','interp','Edgecolor','none','Facelighting','phong'); % 畫三維曲面（色）圖2.1.2 理想高通濾波器實踐結(jié)果截圖：2.2.1 Butterworth高通濾波器實踐代碼：I1=imread('flower.bmp');subplot(121),imshow(I1);title(&#

4、39;原始圖像');f=double(I1);g=fft2(f);g=fftshift(g);N1,N2=size(g);n=2;d0=5;n1=fix(N1/2);n2=fix(N2/2);for i=1:N1 for j=1:N2 d=sqrt(i-n1)2+(j-n2)2); if d=0 h=0; else h=1/(1+(d0/d)(2*n); end result(i,j)=h*g(i,j); endendresult=ifftshift(result);X2=ifft2(result);X3=uint8(real(X2);subplot(122),imshow(X3) ;

5、title('Butterworth高通濾波');I1=imread('flower.bmp');f1,f2=freqspace(size(I1),'meshgrid');D=0.3;r=f1.2+f2.2;n=4;for i=1:size(I1,1) for j=1:size(I1,2) t=(D*D)/r(i,j); Hd(i,j)=1/(tn+1); endendfiguresurf(Hd,'Facecolor','interp','Edgecolor','none','

6、;Facelighting','phong'); % 畫三維曲面（色）圖2.2.2 Butterworth高通濾波器實踐結(jié)果截圖：2.3.1 高斯高通濾波器實踐代碼：clear allIA=imread('girl.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);title('原始圖像');subplot(2,2,2),imshow(uint8(Ia);title('高斯高通濾波');figuresurf(Hd,'Facecolor','i