[MATLAB图像处理] 关于椭圆灰度检测的程序，帮忙看一下，我看不太懂

[djdj]

format long
P=imread('picture.bmp');
lefttop=[100 240
142 244
170 258
450 545
471 543];
rightbutton=[200 368
375 466
591 685
200 330
537 624];

for circle=1:5
circle
if(circle~=1)
clear u;
clear v;
end
k=1;
for i=lefttop(circle,1):lefttop(circle,2);
flag=0;
for j=rightbutton(circle,1):rightbutton(circle,2);
if flag==0 & P(i,j)<10
u(k)=i;
v(k)=j;
k=k+1;
flag=1;
elseif flag==1 & P(i,j)<10 & P(i,j+1)>200
u(k)=i;
v(k)=j;
k=k+1;
end
end
end
for j=rightbutton(circle,1):rightbutton(circle,2)
flag=0;
for i=lefttop(circle,1):lefttop(circle,2)
if flag==0 & P(i,j)<10
f1=0;
for temp=1:k-1
if u(temp)==i & v(temp)==j
f1=1;
end
end
if f1==0
u(k)=i;
v(k)=j;
k=k+1;
flag=1;
end
elseif flag==1 & P(i,j)<10 & P(i+1,j)>200
f1=0;
for temp=1:k-1
if u(temp)==i & v(temp)==j
f1=1;
end
end
if f1==0
u(k)=i;
v(k)=j;
k=k+1;
flag=1;
end
end
end
end
axis equal;
axis([1 768 1 1024]);

plot(u,v,'.');grid on ;hold on;

x=ones(k-1,5);
y=ones(k-1,1);

for i=1:k-1
x(i,=[1 v(i) u(i) u(i)*v(i) v(i)*v(i) ];
y(i)=-u(i)*u(i);
end

[b,bint,r,rint,stats]=regress(y,x);
b
bint
stats
A=[2 b(4);
b(4) 2*b(5)];
B=[-b(3);-b(2)];
X=A\B
xo=(X(2)-512)/3.78
yo=(384-X(1))/3.78
xlswrite(strcat('d:/',num2str(circle),'.xls'),[u;v]');
end