clc;
clear?all;
%reading?and?showing
f1=imread（‘foreground.jpg‘）;
%converting?color?image?to?grayimage
f2=rgb2gray（f1）;
figure（1）imshow（f2）;
%reading?and?showing
f3=imread（‘background.jpg‘）;
%converting?color?image?to?grayimage
f4=rgb2gray（f3）;
figure（2）imshow（f4）;
%background?subtracting
f5=abs（double（f2）-double（f4））;
[M?N]=size（f5）;
T=20;
for?i=1:M
???for?j=1:N
??????if?f5（ij）>T
?????????f5（ij）=255;
??????else
?????????f5（ij）=0;
??????end
???end
end
f5=uint8（f5）;
figure（3）;
imshow（f5）;

%?imclose?the?image
se=strel（‘disk‘3）;
f6=imclose（f5se）;
figure（4）;
imshow（f6）;

%?fill?the?image
f8=imfill（f6）;
figure（5）;
imshow（f8）;

%?smooth?the?image
f9=double（f8）/255;
f10=medfilt2（f9[3?3]）;
figure（6）;
imshow（f10[]）;

%?add?label?to?the?image
bw1=im2bw（f10）;
[xnum]=bwlabel（bw14）;

%?calculate?the?number?of?pixels?of?each?labeled?area
long=1:num;
for?i=1:num
[rc]=find（x==i）;
rc=[r?c];
long（i）=size（rc1）;
end
%?display?the?number?of?pixels?of?each?labeled?area
for?j=1:num
????disp（long（j））;
end
%?calculate?which?area?has?the?biggest?number?of?pixels
max=0;
for?k=1:num
????if（long（k）>max）?
????????max=long（k）;
????????m=k;
????end
end


%?the?label?of?the?biggest?area
m
%?the?number?of?pixels?of?the?biggest?area
max
%?get?the?image?of?the?biggest?area?
[row?column]=size（x）;
for?i=1:row
????for?j=1:column
????????if（x（ij）==m）
????????????x（ij）=m;
????????else?x（ij）=0;
????????end
????end
end
se=strel（‘disk‘2）;
x=imerode（xse）;

%?display?the?image
figure（7）imshow（x）;
%?get?the?edge?of?the?image
y=edge（x‘canny‘）;
figure（8）imshow（y）;