%
% Retinex 补偿光照不均匀
% 由于卷积时需要保证精度，应先把[0,255]的unit8图像归一化成[0.0,1.0]的浮点型。
% 那么利用matlab实现步骤为：读入图像→归一化→设置高斯函数参数及矩阵→高斯函数和输入图像矩阵卷积→取对数→和输入图像矩阵的对数相差→取指数→输出图像
name = ['g-4-1.png'];
f = imread(name);
% f=imread('H25.jpg');
fr=f(:, :, 1); fg=f(:, :, 2); fb=f(:, :, 3);%RGB通道
mr=mat2gray(im2double(fr)); mg=mat2gray(im2double(fg)); mb=mat2gray(im2double(fb));%数据类型归一化
alf1=1458; %定义标准差alf=a^2/2 a=54
n=161;%定义模板大小
n1=floor((n+1)/2);%计算中心
for i=1:n
for j=1:n
b(i,j) =exp(-((i-n1)^2+(j-n1)^2)/(4*alf1))/(pi*alf1); %高斯函数
end
end
nr1 = imfilter(mr,b,'conv', 'replicate');ng1 = imfilter(mg,b,'conv', 'replicate');nb1 = imfilter(mb,b,'conv', 'replicate');%卷积滤波
ur1=log(nr1); ug1=log(ng1); ub1=log(nb1);
tr1=log(mr);tg1=log(mg);tb1=log(mb);
yr1=(tr1-ur1)/3;yg1=(tg1-ug1)/3;yb1=(tb1-ub1)/3;
alf2=53.38; %定义标准差alf=a^2/2 a=10.3325
x=31;%定义模板大小
x1=floor((n+1)/2);%计算中心
for i=1:n
for j=1:n
a(i,j) =exp(-((i-n1)^2+(j-n1)^2)/(4*alf2))/(6*pi*alf2); %高斯函数
end
end
nr2 = imfilter(mr,a,'conv', 'replicate');ng2 = imfilter(mg,a,'conv', 'replicate');nb2 = imfilter(mb,a,'conv', 'replicate');%卷积滤波
ur2=log(nr2); ug2=log(ng2); ub2=log(nb2);
tr2=log(mr);tg2=log(mg);tb2=log(mb);
yr2=(tr2-ur2)/3;yg2=(tg2-ug2)/3;yb2=(tb2-ub2)/3;
alf3=13944.5; %定义标准差alf=a^2/2 a=167
l=501;%定义模板大小
l1=floor((n+1)/2);%计算中心
for i=1:n
for j=1:n
e(i,j) =exp(-((i-n1)^2+(j-n1)^2)/(4*alf3))/(4*pi*alf3); %高斯函数
end
end
nr3 = imfilter(mr,e,'conv', 'replicate');ng3 = imfilter(mg,e,'conv', 'replicate');nb3 = imfilter(mb,e,'conv', 'replicate');%卷积滤波
ur3=log(nr3); ug3=log(ng3); ub3=log(nb3);
tr3=log(mr);tg3=log(mg);tb3=log(mb);
yr3=(tr3-ur3)/3;yg3=(tg3-ug3)/3;yb3=(tb3-ub3)/3;
dr=yr1+yr2+yr3;dg=yg1+yg2+yg3;db=yb1+yb2+yb3;
cr=im2uint8(dr); cg=im2uint8(dg); cb=im2uint8(db);
z=cat(3, cr, cg, cb);
figure(1), imshow(z)
figure(2), imshow(f)
ibw = im2bw(z, graythresh(z));
figure(3); imshow(ibw);
I2 = imclose(ibw,ones(5,5));
figure(4); imshow(I2);
I2 = imopen(I2,ones(5,5));
figure(5); imshow(I2);
bw = im2bw(f, graythresh(f));
subplot(2,2,1);imshow(f);
% title('原图像');
subplot(2,2,3);imshow(z);
% title('增强图像');
subplot(2,2,2);imshow(bw);
% title('原图像二值化后的图像');
subplot(2,2,4);imshow(I2);
% title('增强图像二值化后的图像');
imwrite(z,'增强后.png');
%}
%{
% 测试顶帽变换
for i = 1:1
% II = imread(['C:\Documents and Settings\Administrator\桌面\tophat\' int2str(i) '.png']);
name = ['C:\Documents and Settings\Administrator\桌面\tophat\g-4-1.png'];
II = imread(name);
I = rgb2gray(II);
% name = ['C:\Documents and Settings\Administrator\桌面\tophat\g-' int2str(i) '.png'];
% imwrite(II, name);
% subplot(1,4,1);
figure(1);
imshow(I);
thresh = graythresh(I);
ibw = im2bw(I, thresh);
% subplot(1,4,2);
figure(2);
imshow(ibw);
bg = imopen(I, strel('disk', 50));
figure(6);imshow(bg);
Itophat = imsubtract(I, bg);
% subplot(1,4,3);
figure(3);
imshow(Itophat)
% I2=Itophat;
I2 = imadjust(Itophat);
% subplot(1,4,4);
figure(4);
imshow(I2);
ibw2 = im2bw(I2, graythresh(I2));
% subplot(1,4,4); imshow(ibw2);
figure(5);
imshow(ibw2);
end
close all
%}
