clear all

rgb=imread('g3.jpg');%需要处理的图片

m=size(rgb,1);

n=size(rgb,2);

for k=0:255

rr0(k+1)=length(find(rgb(:,:,1)==k))/(m*n); %计算每级灰度出现的概率，将其存入GP中相应位置

end

figure,bar(0:255,rr0,'g') %绘制直方图

title('原图像直方图')

for i=1:m

for j=1:n

rr(i,j)=logm(double(rgb(i,j,1))+eps);

gg(i,j)=logm(double(rgb(i,j,2))+eps);

bb(i,j)=logm(double(rgb(i,j,3))+eps);

end

end

rr=rr/max(max(rr(:)));

gg=gg/max(max(gg(:)));

bb=bb/max(max(bb(:)));

rrr= retinex_frankle_mccann(rr, 8);

ggg= retinex_frankle_mccann(gg, 8);

bbb= retinex_frankle_mccann(bb, 8);

rgg=(rrr.*ggg.*bbb).^(1/3);

for i=1:m

for j=1:n

rrr(i,j)=round(exp(rrr(i,j)*5.54));

ggg(i,j)=round(exp(ggg(i,j)*5.54));

bbb(i,j)=round(exp(bbb(i,j)*5.54));

end

end

rgb=cat(3,uint8(rrr),uint8(ggg),uint8(bbb));

rgb=max(min(rgb,255),0);

for k=0:255

rr0(k+1)=length(find(rgb(:,:,1)==k))/(m*n); %计算每级灰度出现的概率，将其存入GP中相应位置

end

figure,bar(0:255,rr0,'g') %绘制直方图

title('原图像直方图')

sz=size(rgb);

m=sz(1,1);

n=sz(1,2);

rr=rgb(:,:,1);

gg=rgb(:,:,2);

bb=rgb(:,:,3);

rr0=find2(rr)/(m*n); %计算每级灰度出现的概率，将其存入GP中相应位置

rr1(1,1)=rr0(1,1);

for k=2:256

rr1(1,k)=rr1(1,k-1)+rr0(1,k);

end

S2=round((rr1*255)+0.5); %将Sk归到相近级的灰度

rrr=rr;

ggg=gg;

bbb=bb;

for i=0:255

rrr(find(rr==i))=S2(i+1); %将各个像素归一化后的灰度值赋给这个像素

ggg(find(gg==i))=S2(i+1);

bbb(find(bb==i))=S2(i+1);

end

rgb1=cat(3,rrr,ggg,bbb);

rgb1=max(min(rgb1,255),0);

for k=0:255

rr0(k+1)=length(find(rgb1(:,:,1)==k))/(m*n); %计算每级灰度出现的概率，将其存入GP中相应位置

end

figure,bar(0:255,rr0,'g') %绘制直方图

title('原图像直方图')

figure,imshow(rgb1)

function Retinex = retinex_frankle_mccann(L, nIterations)

global RR IP OP NP Maximum

RR = L;

Maximum = max(L(:)); % maximum color value in the image

[nrows, ncols] = size(L);

shift = 2^(fix(log2(min(nrows, ncols)))-1); % initial shift

OP = Maximum*ones(nrows, ncols); % initialize Old Product

while (abs(shift) >= 1)

for i = 1:nIterations

CompareWith(0, shift); % horizontal step

CompareWith(shift, 0); % vertical step

end

shift = -shift/2;