图像预处理的一般方法

1、精选优质文档-倾情为你奉上图像预处理的一般方法（一）空域图像增强技术1灰度线性变换addpath('C:'); I = imread('C:lzs.jpeg');imshow(I);I = double(I);M,N = size(I);for i = 1:M for j = 1:N if I(i,j)<=30 I(i,j)=I(i,j); else if I(i,j)<=150 I(i,j)=(210-30)/(160-30)*(I(i,j)-30)+30; else I(i,j)=(256-210)/(256-160)*(I(i,j)-160)+

2、210; end end endendfigure(2);imshow(uint8(I);2.直方图均衡化addpath('C:');I=imread('C:lzs.jpeg');figuresubplot(221); imshow(I);subplot(222);imhist(I);I1=histeq(I);figure;subplot(221);imshow(I1);subplot(222);imhist(I1) 3.均值滤波function test1I = imread('C:lzs.jpeg');M,N=size(I);II1=zero

3、s(M,N);for i=1:16; II(:,:,i)=imnoise(I,'gaussian',0,0.01); II1=II1+double(II(:,:,i); if or(or(i=1,i=4),or(i=8,i=16); figure;imshow(uint8(II1/i); end end4.梯度锐化操作addpath('C:'); I = imread('C:lzs.jpeg');subplot(131); imshow(I);H=fspecial('Sobel');H=H'TH=filter2(H,I);

4、subplot(132)；imshow(TH,);H=H'TH=filter2(H,I);subplot(133),imshow(TH,);（二）图像分割1.迭代式阈值选择法addpath('C:'); f = imread('C:lzs.jpeg');subplot(1,2,1);imshow(f);title('原始图像');f=double(f);T=(min(f(:)+max(f(:)/2;done=false;i=0whiledone r1=find(f<=T); r2=find(f>T); Tnew=(mean(f

5、(r1)+mean(f(r2)/2; done=abs(Tnew-T)<1 T=Tnew; i=i+1;endf(r1)=0;f(r2)=1;subplot(1,2,2)imshow(f);title('迭代阀值二值化图像');2.用Otsu法进行阈值选择addpath('C:'); f = imread('C:lzs.jpeg'); subplot(2,2,1)imshow(f);title('原始图像');T=graythresh(f);g=im2bw(f,T);subplot(2,2,2);imshow(g);titl

6、e('Otsu方法二值化图像');3.用watershed算法分割图像addpath('C:'); f = imread('C:lzs.jpeg');subplot(2,2,1)imshow(f);title('(a)原始图像');subplot(2,2,2);f=double(f);hv=fspecial('prewitt');hh=hv.'gv=abs(imfilter(f,hv,'replicate');gh=abs(imfilter(f,hv,'replicate')

7、;g=sqrt(gv.2+gh.2);subplot(2,2,2);L=watershed(g);wr=L=0;imshow(wr);title('(b)分水岭');f(wr)=255;subplot(2,2,3);imshow(uint8(f);title('(c)分割结果');rm=imregionalmin(g);subplot(2,2,4);imshow(rm);title('(d)局部极小值');（三）膨胀和腐蚀1.膨胀操作addpath('C:'); I = imread('C:yb.jpg'); subplot(121);imshow(I);title('原始图像')se=strel('ball',8,8);I2=imdilate(I,se);subplot(122);imshow(I2);title('膨胀后的图像')2.腐蚀操作addpath('C:'); I = imread('C:yb.jpg');subplot(121);imshow(I);ti