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harris_corner_detector [2013/04/14 02:30]
jongbor [How to find corners]
harris_corner_detector [2014/04/19 15:41] (current)
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 ===== Practical matters ===== ===== Practical matters =====
  
-Since computing eigenvalues can be expensive, it is preferred to calculate the score $R = det(M)-k\cdot trace(M)^2$,​ where $k$ is an empirically determined constant, in order to compute the "​cornerness"​ of a point.+Since computing eigenvalues can be expensive, it is preferred to calculate the score $R = det(M)-k\cdot trace(M)^2$,​ where $k$ is an empirically determined constant, in order to compute the "​cornerness"​ of a point. $R$ preserves information about the eigenvalues since $det(M) = \lambda_1\lambda_2$ and $trace(M) = \lambda_1 + \lambda_2$ but it is also easier to calculate. 
 + 
 +MATLAB implementations can be found [[http://​www.csse.uwa.edu.au/​~pk/​research/​matlabfns/​Spatial/​harris.m|here]] and [[http://​www.di.ens.fr/​willow/​events/​cvml2013/​scholarship/​application/​harris.m|here]].