%Thinning
clc
clear all;
I=rgb2gray(imread('img\ImageProcess_blk2.jpg'));
% I=rgb2gray(imread('img\horse.png'));
subplot(121),imshow(I);title('Original');
Ibw=im2bw(I); %binaryzation
subplot(222),imshow(Ibw);title('binaryzation');
[row,col]=size(I);

% for i=1:row
% for j=1:col
% 
% if I(i,j)>100
% Ibw(i,j)=1;
% else
% Ibw(i,j)=0;
% end
% 
% end
% end
% subplot(122),imshow(Ibw);title('Original');

for i=3:row-2
for j=3:col-2

p0=Ibw(i,j);
p1=Ibw(i,j+1);
p2=Ibw(i-1,j+1);
p3=Ibw(i-1,j);
p4=Ibw(i-1,j-1);
p5=Ibw(i,j-1);
p6=Ibw(i+1,j-1);
p7=Ibw(i+1,j);
p8=Ibw(i+1,j+1);

p9=Ibw(i+1,j+2);
p10=Ibw(i,j+2);
p11=Ibw(i-1,j+2);
p12=Ibw(i-2,j+2);
p13=Ibw(i-2,j+1);
p14=Ibw(i-2,j);
p15=Ibw(i-2,j-1);
p16=Ibw(i-2,j-2);
p17=Ibw(i-1,j-2);
p18=Ibw(i,j-2);
p19=Ibw(i+1,j-2);
p20=Ibw(i+2,j-2);
p21=Ibw(i+2,j-1);
p22=Ibw(i+2,j);
p23=Ibw(i+2,j+1);
p24=Ibw(i+2,j+2);

Np0=p1+p2+p3+p4+p5+p6+p7+p8; 
pCenter0=[p1,p2,p3,p4,p5,p6,p7,p8,p1];
pCenter5=[p0,p3,p4,p17,p18,p19,p6,p7,p0];
pCenter7=[p8,p1,p0,p5,p6,p21,p22,p23,p8];
for m=1:8

if (pCenter0(m)==0)&&(pCenter0(m+1)==1)
TCenter0(m)=1;
else
TCenter0(m)=0;
end

if (pCenter5(m)==0)&&(pCenter5(m+1)==1)
TCenter5(m)=1; 
else
TCenter5(m)=0;
end

if (pCenter7(m)==0)&&(pCenter7(m+1)==1)
TCenter7(m)=1;
else
TCenter7(m)=0;
end

end
Sp0=sum(TCenter0); %求Sp0
Sp5=sum(TCenter5); %求Sp5
Sp7=sum(TCenter7); %求Sp7

if (2<=Np0&&Np0<=6)&& (Sp0==1)&&(p1*p3*p7==0||Sp5~=1)&&(p3*p5*p7==0||Sp7~=1)
p0=0;
Ibw(i,j)=0;
end

end
end
subplot(122),imshow(~Ibw);title('Ibw');