matlab实现RGB与HSI的相互转换.doc

%将RGB图像转换为HSI图像% 显示HSI图像%直方图均衡化HSI图像%将HSI图像转换回RGB图像function rgbtohsi(x)F=imread(x);F=im2double(F);r=F(:,:,1);g=F(:,:,2);b=F(:,:,3);th=acos(0.5*(r-g)+(r-b)./(sqrt(r-g).2+(r-b).*(g-b)+eps);H=th;H(bg)=2*pi-H(bg);H=H/(2*pi);S=1-3.*(min(min(r,g),b)./(r+g+b+eps);I=(r+g+b)/3;hsi=cat(3,H,S,I);HE=H*2*pi;HE=histeq(HE);HE=HE/(2*pi);SE=histeq(S);IE=histeq(I);choice=input(1:RGB 转换为 HSIn2:显示HSI图像n3:HSI转换为RGB图像n4:色调均衡n5:饱和度均衡n6:亮度均衡 n7:HSI均衡n 输入您的选择 :);switch choicecase 1figure,imshow(F),title(RGB 图像);figure, imshow(hsi),title(HSI 图像);case 2figure,imshow(F),title(RGB 图像);figure, imshow(H),title(Hue 图像);figure, imshow(S),title(饱和度图像);figure, imshow(I),title(亮度图像); case 3C=hsitorgb(hsi);figure,imshow(hsi),title(HSI 图像);figure, imshow(C),title(RGB 图像);case 4RV=cat(3,HE,S,I);C=hsitorgb(RV);figure,imshow(hsi),title(HSI 图像);figure,imshow(F),title(RGB 图像);figure, imshow(C),title(RGB Image-Hue Equalized);case 5RV=cat(3,H,SE,I);C=hsitorgb(RV);figure,imshow(hsi),title(HSI 图像);figure,imshow(F),title(RGB 图像);figure, imshow(C),title(RGB 饱和度均衡);case 6RV=cat(3,H,S,IE);C=hsitorgb(RV);figure,imshow(hsi),title(HSI 图像);figure,imshow(F),title(RGB 图像);figure, imshow(C),title(RGB 亮度均衡);case 7RV=cat(3,HE,SE,IE);C=hsitorgb(RV);figure,imshow(hsi),title(HSI 图像);figure,imshow(F),title(RGB 图像);figure, imshow(C),title(RGB HSI 均衡);otherwisedisplay(选择错误);endend%函数，将HSI图像转换为RGB图像function C=hsitorgb(hsi)HV=hsi(:,:,1)*2*pi;SV=hsi(:,:,2);IV=hsi(:,:,3);R=zeros(size(HV);G=zeros(size(HV);B=zeros(size(HV);%RG Sectorid=find(0=HV)& (HV2*pi/3);B(id)=IV(id).*(1-SV(id);R(id)=IV(id).*(1+SV(id).*cos(HV(id)./cos(pi/3-HV(id);G(id)=3*IV(id)-(R(id)+B(id);%BG Sectorid=find(2*pi/3=HV)& (HV4*pi/3);R(id)=IV(id).*(1-SV(id);G(id)=IV(id).*(1+SV(id).*cos(HV(id)-2*pi/3)./cos(pi-HV(id);B(id)=3*IV(id)-(R(id)+G(id);%BR Sectorid=find(4*pi/3=HV)& (HV2*pi);G(id)=IV(id).*(1-SV(id);B(id)=IV(id).*(1+SV(id).*cos(HV(id)-4*pi/3)./cos(5*pi/3-HV(id);R(id)=3*IV(