hi,
i tired to write a fast code, try it and see :
I=imread('dcircle.png'); % that image with deformed circle.
X=rgb2gray(I);
N=size(X);
% finding an approximation of the center
% you take where you want start counting
xc=100;
n=0; % number of black pixels vertically descending
for y=1:N(2)
if X(xc,y)>0.70;
n=n+1;
end
end
% the center is then given by :
r=n/4;
yc=N(2)/2;
Y=zeros(N(1),N(2));
for x=1:N(1)
for y=1:N(2)
rt=sqrt(((x-xc)^2)+((y-yc)^2));
if rt>=r
Y(x,y)=1;
end
end
end
figure,subplot(1,2,1), imshow(X),title(' initial');
subplot(1,2,2), imshow(Y), title(' adjusted');
