hue_shift.zip_RGB to HIS matlab_hue shift_shiftHue_ue中的hue shift

function [ imageout ] = hue_shift( image, degree) %To shift the hue of pictures % I=imread(image); I=im2double(I); R=I(:,:,1); G=I(:,:,2); B=I(:,:,3); [row,col,n]=size(I); HSI_S=double(zeros(row,col)); HSI_H=double(zeros(row,col)); for i=1:row for j=1:col minrgb=min(R(i,j),G(i,j)); minrgb=min(minrgb,B(i,j)); HSI_S(i,j)=1-3/(R(i,j)+G(i,j)+B(i,j))*minrgb; deno=sqrt( ( R(i,j)-G(i,j) )^2 + ( R(i,j)-B(i,j) )*( G(i,j)-B(i,j) ) ); theta=acos(0.5*(R(i,j)-G(i,j)+R(i,j)-B(i,j))/deno); if(B(i,j)<=G(i,j)) HSI_H(i,j)=theta; else HSI_H(i,j)=2*pi-theta; end HSI_H(i,j)=HSI_H(i,j)+degree*pi/3; end end HSI_I=(R+G+B)/3; %imagetmp=cat(3,HSI_H,HSI_S,HSI_I); %figure; %subplot(1,3,1); %imshow(imageout); r=double(zeros(size(HSI_H))); g=double(zeros(size(HSI_H))); b=double(zeros(size(HSI_H))); for i=1:row for j=1:col v2=HSI_I(i,j)*(1-HSI_S(i,j)); if(HSI_H(i,j)>=0&&HSI_H(i,j)<2/3*pi) r(i,j)=HSI_I(i,j)*(1+HSI_S(i,j)*cos(HSI_H(i,j))/cos(pi/3-HSI_H(i,j))); b(i,j)=v2; g(i,j)=3*HSI_I(i,j)-b(i,j)-r(i,j); elseif(HSI_H(i,j)>=2/3*pi&&HSI_H(i,j)<4/3*pi) r(i,j)=v2; g(i,j)=HSI_I(i,j)*(1+HSI_S(i,j)*cos(HSI_H(i,j)-2*pi/3)/cos(pi-HSI_H(i,j))); b(i,j)=3*HSI_I(i,j)-r(i,j)-g(i,j); else b(i,j)=HSI_I(i,j)*(1+HSI_S(i,j)*cos(HSI_H(i,j)-4*pi/3)/cos(5*pi/3-HSI_H(i,j))); g(i,j)=v2; r(i,j)=3*HSI_I(i,j)-b(i,j)-g(i,j); end end end imageout=cat(3,r,g,b); figure; imageout=im2double(imageout); imshow(imageout); end