I=imread('D:\project1.jpg');
I=im2double(I);
[M,N]=size(I);
figure(1);
imshow(I);
title('source');
figure(2);
[H,x]=imhist(I,32);
stem(x,(H/M/N),'.');
title('source1');
%增加对比度
A=2;B=-55;
O=A.*I+B/255;
figure(3);
subplot(2,2,1);
imshow(O);
figure(4);
subplot(2,2,1);
[H,x]=imhist