I calculated the 3x3 homography matrix and I need to get rotation, translation, shear and scale to use them as parameters in the windows8 media element attributes ?!
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1You can start with this link:[find-the-rotation-and-skew-of-a-matrix-transformation][1] [1]: http://stackoverflow.com/questions/5107134/find-the-rotation-and-skew-of-a-matrix-transformation – Pieter Geerkens Mar 14 '13 at 21:40
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see https://math.stackexchange.com/questions/78137/decomposition-of-a-nonsquare-affine-matrix
def getComponents(normalised_homography):
'''((translationx, translationy), rotation, (scalex, scaley), shear)'''
a = normalised_homography[0,0]
b = normalised_homography[0,1]
c = normalised_homography[0,2]
d = normalised_homography[1,0]
e = normalised_homography[1,1]
f = normalised_homography[1,2]
p = math.sqrt(a*a + b*b)
r = (a*e - b*d)/(p)
q = (a*d+b*e)/(a*e - b*d)
translation = (c,f)
scale = (p,r)
shear = q
theta = math.atan2(b,a)
return (translation, theta, scale, shear)
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Tom Larkworthy
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why is the normalized homography 2x3 matrix in your input argument? – Farid Alijani Jun 04 '19 at 09:06
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@FäridAlijani in my case, it was the homography matrix (H) computed using OpenCV `(H, mask) = cv2.findHomography(ptsA, ptsB, method=cv2.RANSAC)` – NightFury13 Oct 05 '20 at 14:38