matlab 图像中加入噪声.doc

《matlab 图像中加入噪声.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Matlab中图片加入噪声1、添加的是20%的随即噪声小波变换，加噪，去噪，增强%《Denoisingandcontrastenhancementviawaveletshrinkageandnonlinearadaptivegain》clear;clcimage=imread('555.jpg');image=imread('555.jpg');figure;imshow(image);title('theoriginalimage');%加噪image=double(image);I=image+20*randn(size

2、(image));figure;imshow(uint8(I));title('noisedimage');%小波分解dwtmode('per');[a1,h1,v1,d1]=dwt2(I,'sym8');%从1到3分辨率递减[a2,h2,v2,d2]=dwt2(a1,'sym8');[a3,h3,v3,d3]=dwt2(a2,'sym8');%计算去噪时的阈值sigma=median(abs(d1(:)))/0.6745;%确定噪声标准差thr=2*sigma;%权值根据实际情况选取thr1=thr*2^(-(3-1)/2

3、);%分层阈值，从1到3分辨率递增，即这里的th1对应于小波系数的第3层thr2=thr*2^(-(3-2)/2);thr3=thr*2^(-(3-3)/2);%去噪ccch=soft_t(h3,thr1);cccv=soft_t(v3,thr1);cccd=soft_t(d3,thr1);cch=soft_t(h2,thr2);ccv=soft_t(v2,thr2);ccd=soft_t(d2,thr2);ch=soft_t(h1,thr3);cv=soft_t(v1,thr3);cd=soft_t(d1,thr3);%重

4、构去噪图像cca=idwt2(a3,ccch,cccv,cccd,'sym8');ca=idwt2(cca,cch,ccv,ccd,'sym8');J1=idwt2(ca,ch,cv,cd,'sym8');J1=uint8(J1);figure;imshow(J1);title('denoisedimage');p=psnr(image,J1)2、加高斯白噪声%加噪image=double(image);I=awgn(image,5);%加入信噪比为5分贝的高斯白噪声figure;imshow(uint8(I));title

5、('noisedimage');