How to detect specific shaped objects with any different orientations in Image processing ?
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Hello, I want to know that how to detect the objects with different orientations using Area ratio, in which the problem is the bounding box is not oriented with the same orientation as the object, due to that the area ratio is not accurate and object with different orientation is not detected. How to rotate the bounding box also with the same angle as the object orientation....?
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KSSV
on 26 Dec 2018
YOu can rotate the bounding box by using your desired angle as below:
% bounding box coordinates
B = [ 0 0 ; 1 0 ; 1 1 ;0 1 ; 0 0]' ;
th = pi/4 ;
R = [cos(th) -sin(th) ; sin(th) cos(th)] ;
% Rotate by th
B1 = R*(B-mean(B,2))+mean(B,2) ;
figure
hold on
patch(B(1,:),B(2,:),'r')
patch(B1(1,:),B1(2,:),'k')
Image Analyst
on 26 Dec 2018
Take a look at Hu's moments which are rotationally invariant: Click here
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Image Analyst
on 26 Dec 2018
See my shape recognition demo, attached. It puts up simple polygons of various numbers of vertices, angles, and sizes, and then finds them.
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