matlab彩色图像直方图均衡化

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参考《数字图像处理基础》p44页直方图均衡化方法，从黑白图像转变彩色图像的均衡化处理

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I=[1 3 9 9 8
    2 1 3 7 3
    3 6 0 6 4
    6 8 2 0 5
    2 9 2 6 0];
[M, N]=size(I);
h=zeros(1,10);
for i=1:M
    for j=1:N
        h(1,I(i,j)+1)=h(1,I(i,j)+1)+1;
    end
end
I2=9*cumsum(h/25);
I2(1,1)=0;
I3=round(I2);
G=size(I);
for i=1:M
    for j=1:N
        for k=1:10
        if (I(i,j)==k-1)
            G(i,j)=I3(1,k);
        end
        end
    end
end

按照书上的可知输出的G如书上或下图所示

彩色图像直方图均衡化如下

I=imread('c.jpg');
% f=rgb2gray(I);
% figure
subplot(121);
imshow(I);
[M,N,V]=size(I);
h1=zeros(1,256);
h2=zeros(1,256);
h3=zeros(1,256);
for i=1:M
    for j=1:N
        h1(1,I(i,j,1)+1)=h1(1,I(i,j,1)+1)+1;
    end
end
for i=1:M
    for j=1:N
        h2(1,I(i,j,2)+1)=h2(1,I(i,j,2)+1)+1;
    end
end
for i=1:M
    for j=1:N
        h3(1,I(i,j,3)+1)=h3(1,I(i,j,3)+1)+1;
    end
end

I21=255*cumsum(h1/(M*N));
I21(1,1)=0;
I3(:,:,1)=round(I21);

I22=255*cumsum(h2/(M*N));
I22(1,1)=0;
I3(:,:,2)=round(I22);

I23=255*cumsum(h3/(M*N));
I23(1,1)=0;
I3(:,:,3)=round(I23);

G=size(I);
for i=1:M
    for j=1:N
        for u=1:V
            for k=1:256
            if (I(i,j,u)==k-1)
                G(i,j,u)=I3(1,k,u);
            end
            end
        end
    end
end
G=uint8(G);
subplot(122);
imshow(G);