彩色图像RGB模型与HSI模型的转换

M函数代码部分
function hsi=rgb2hsi(rgb)
rgb=im2double(rgb);
r=rgb(:,:,1);
g=rgb(:,:,2);
b=rgb(:,:,3);
num=0.5*((r-g)+(r-b));
den=sqrt((r-g).^2+(r-b).*(g-b));
theta=acos(num./(den+eps));

H=theta;
H(b>g)=2*pi-H(b>g);
H=H/(2*pi);

num=min(min(r,g),b);
den=r+g+b;
den(den==0)=eps;
S=1-3.*num./den;

H(S==0)=0;

I=(r+g+b)/3;
hsi=cat(3,H,S,I);

work区部分

>> f=imread('ppd1.jpg');
>> hsi=rgb2hsi(f);
>> g=rgb2gray(hsi);
>> q=imhist(g);
>> m=q(1:10:256);
>> n=1:10:256;
>> bar(n,m)

PS