用Matlab绘彩色图像的直方图

直方图是常用的图表，用MATLAB实现如下：

Img=imread('football.jpg');
BW = Img;
R=BW(:,:,1);
[REDcounts,x] = imhist(R);
G=BW(:,:,2);
[Greencounts,y] = imhist(R);
B=BW(:,:,3);
[Bluecounts,z] = imhist(R);
figure;
subplot(131);imhist(R);title('histogram of Red');
subplot(132);imhist(G);title('histogram of Green');
subplot(133);imhist(B);title('histogram of Blue');
figure;
Histcounts=REDcounts+Greencounts+Bluecounts;
Histogramdata=Histcounts';
plot(Histogramdata);