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How to calculate the angle between two lines from the same origin?
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Please I need help on this, I have extracted severla minutia points from this fingerprint image and I have been able to calculate the angle of each minutia according to the ridge direction, which i have dipslayed in green small arrows, and i want to take one of the minutia as a reference point and calculate the distance and angle each other minutia forms with the reference minutia, that is the angles in orange color, please help me on this. thanks
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KSSV
2020-6-9
O = [0. 0.] ; % origin
% Two points
A = rand(1,2) ;
B = rand(1,2) ;
u = O-A ;
v = O-B ;
CosTheta = (dot(u,v) / (norm(u)*norm(v)));
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David Hill
2020-6-9
Seems like just a math problem. If you have two vectors A and B, then angle between them is:
angle = acos(dot(A,B)/norm(A)/norm(B));
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David Hill
2020-6-9
You need four pixel points, to generate the three vectors from the origin. It does not matter what the magnitudes are since they get divided out to compute the angle.
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