图像增强处理：空间域与频率域结合的图像增强算法

clear;clc; figure; yt=imread('H:\大学\数字图象处理\课程设计2\dogOriginal.bmp'); yt_noise=imread('H:\大学\数字图象处理\课程设计2\dogDistorted.bmp'); subplot(4,3,1);imshow(yt);title('原图'); subplot(4,3,3);imhist(yt);title('原图'); a=fftshift(fft2(yt)); subplot(4,3,2);imshow(mat2gray(log(abs(a))));title('原图频谱图'); subplot(4,3,4);imshow(yt_noise);title('噪声图'); subplot(4,3,6);imhist(yt_noise);title('噪声图'); a=fftshift(fft2(yt_noise)); subplot(4,3,5);imshow(mat2gray(log(abs(a))));title('噪声图频谱图'); A=fspecial('average'); qsjnoise=filter2(A,yt_noise)/255; subplot(4,3,7);imshow(qsjnoise);title('去随机噪声'); subplot(4,3,9);imhist(qsjnoise);title('去随机噪声'); a=fftshift(fft2(qsjnoise)); subplot(4,3,8);imshow(mat2gray(log(abs(a))));title('去随机噪声后频谱图'); x=double(qsjnoise); x1=fftshift(fft2(qsjnoise)); x2=x1; [m,n]=size(x1); nn=2; d0=30; m0=fix(m/2); n0=fix(n/2); for i=1:m for j=1:n d=sqrt((i-m0)^2+(j-n0)^2); h=1*exp(-1/2*(d^2/d0^2)); x2(i,j)=h*x1(i,j); end end qnoise=abs(ifft2(x2)); qnoise=mat2gray(qnoise); subplot(4,3,10);imshow(qnoise);title('去噪声'); subplot(4,3,12);imhist(qnoise);title('去噪声'); a=fftshift(fft2(qnoise)); subplot(4,3,11);imshow(mat2gray(log(abs(a))));title('去噪声后频谱图'); cha=yt-uint8(qnoise); he=sum(sum(cha)); avg=he/(m*n); wucha=cha-avg; result1=(sum(sum(wucha.^2)))/(m*n); if result1==0 disp('dog图均方误差');result2=0 else disp('dog图均方误差');result2=sqrt(result1) end figure; yt=imread('H:\大学\数字图象处理\课程设计2\swanOriginal.bmp'); yt_noise=imread('H:\大学\数字图象处理\课程设计2\swanNoise.bmp'); subplot(4,3,1);imshow(yt);title('原图'); subplot(4,3,3);imhist(yt);title('原图'); a=fftshift(fft2(yt)); subplot(4,3,2);imshow(mat2gray(log(abs(a))));title('原图频谱图'); subplot(4,3,4);imshow(yt_noise);title('噪声图'); subplot(4,3,6);imhist(yt_noise);title('噪声图'); a=fftshift(fft2(yt_noise)); subplot(4,3,5);imshow(mat2gray(log(abs(a))));title('噪声图频谱图'); qjynoise=medfilt2(yt_noise,[3,3]); subplot(4,3,7);imshow(qjynoise);title('去随机噪声'); subplot(4,3,9);imhist(qjynoise);title('去随机噪声'); a=fftshift(fft2(qjynoise)); subplot(4,3,8);imshow(mat2gray(log(abs(a))));title('去随机噪声后频谱图'); x=double(qjynoise); x1=fftshift(fft2(qjynoise)); x2=x1; [m,n]=size(x1); nn=2; d0=30; m0=fix(m/2); n0=fix(n/2); for i=1:m for j=1:n d=sqrt((i-m0)^2+(j-n0)^2); h=1/(1+0.414*(d/d0)^(2*nn)); x2(i,j)=h*x1(i,j); end end qnoise=abs(ifft2(x2)); subplot(4,3,10);imshow(qnoise,[]);title('去噪声'); subplot(4,3,12);imhist(mat2gray(qnoise));title('去噪声'); a=fftshift(fft2(qnoise)); subplot(4,3,11);imshow(mat2gray(log(abs(a))));title('去噪声后频谱图'); cha=yt-uint8(qnoise); he=sum(sum(cha)); avg=he/(m*n); wucha=cha-avg; result1=(sum(sum(wucha.^2)))/(m*n); if result1==0 disp('swan图均方误差');result2=0 else disp('swan图均方误差');result2=sqrt(result1) end %%%%带阻滤波器，线性滤波器