[Carol]

这样好像能实现，改变i,j的值，可选择不同区域：
I= imread('图像');
imshow(I)
BW = randn(100,100,3);
for i = 1:100
for j = 1:100
BW = I(i,j,;
end
end
r = BW(:,:,1);
g = BW(:,:,2);
b = BW(:,:,3);
rgb_image = cat(3,r,g,b);
imshow(rgb_image)
R = rgb_image(:,:,1);
G = rgb_image(:,:,2);
B = rgb_image(:,:,3);
m1 = mean(R)
m2 = mean(G)
m3 = mean(B)
我也是刚刚学，多交流!