Dear all,
I have a checker board/chess board pattern detection problem. I am interested in knowing the centres of the squares in my image frame.
I have tried the following approach:
clc;
close all;
clear;
I = imread('23136695_Tilt2.tiff');
I = imadjust(I);
I = I(:, 695:end);
BW = edge(I, 'Canny');
figure;
imshowpair(I,BW,'montage')
figure;
[H,T,R] = hough(BW);
imshow(H,[],'XData',T,'YData',R,...
'InitialMagnification','fit');
xlabel('\theta'), ylabel('\rho');
axis on, axis normal, hold on;
P = houghpeaks(H,40,'threshold',ceil(0.3*max(H(:))));
x = T(P(:,2)); y = R(P(:,1));
plot(x,y,'s','color','white');
lines = houghlines(BW,T,R,P,'FillGap',5,'MinLength',7);
figure, imshow(I), hold on
max_len = 0;
for k = 1:length(lines)
xy = [lines(k).point1; lines(k).point2];
plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','green');
plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','red');
len = norm(lines(k).point1 - lines(k).point2);
if ( len > max_len)
max_len = len;
xy_long = xy;
end
end
As you can see, this is not the desired result. I would need the complete grid detected. Is there a simple, computationally non-intensive (as a last resort, it is still OK to be laborious task as cell centre detection will only be done once) way out to solve this.
