rgbtohsi.m

homomorfic filter image

function [H S I]=rgbtohsi(c)
d=size(c);
for i=1:d(1)
    for j=1:d(2)
        R=c(i,j,1);
        G=c(i,j,2);
        B=c(i,j,3);
        I(i,j)=(1/3)*(R+G+B);
        v1=double(((-1/sqrt(6))*(R+G))+((2/sqrt(6))*B));
        v2=double(((1/sqrt(6))*(R))+((-1/sqrt(6))*G));
        if R==G && R==B && B==G
             H(i,j)=0;
             S(i,j)=0;
        else
            f=v2/v1;
            H(i,j)=atan(f);
            S(i,j)=sqrt(v1^2+v2^2);        
        end
        
    end
end