MATLAB 灰度图直方图均衡化

 1 cl;
 2 img=imread(‘mask.jpg‘);
 3 imshow(img);
 4 [x,y]=size(img);
 5 img_man=zeros(x,y);
 6 img_com=zeros(x,y);
 7 
 8 %% 直方图均衡化算法
 9 Max=max(max(img));
10 Min=min(min(img));
11 Hist=zeros(1,256);
12 for i=1:x
13     for j=1:y
14         Hist(img(i,j)+1)=Hist(img(i,j)+1)+1;
15     end
16 end
17 figure,plot(Hist);
18 
19 p=zeros(1,256);
20 for i=1:256
21     p(i)=Hist(i)/(x*y);
22 end
23 figure,plot(p);
24 
25 c=zeros(1,256);
26 for i=1:256
27     c(i)=sum(p(1:i));
28 end
29 figure,plot(c);
30 
31 for i=1:x
32     for j=1:y
33         img_man(i,j)=c(img(i,j)+1)*(Max-Min)+Min;
34     end
35 end
36 
37 figure,imshow(uint8(img_man))
38 
39 Hist2=zeros(1,256);
40 for i=1:x
41     for j=1:y
42         Hist2(img_man(i,j)+1)=Hist2(img_man(i,j)+1)+1;
43     end
44 end
45 figure,plot(Hist2);
46 
47 %% matlab直方图均衡化函数
48 img_com=histeq(img);     
49 figure,imshow(img_com)
50 
51 Hist3=zeros(1,256);
52 for i=1:x
53     for j=1:y
54         Hist3(img_com(i,j)+1)=Hist3(img_com(i,j)+1)+1;
55     end
56 end
57 figure,plot(Hist3);