getRotationMatrix2D gives error

asked 2016-02-26 00:15:07 -0600

88 ●2 ●8

The python function getRotationMatrix2D as follows

center = tuple(np.array(image.shape)/2)
rot_mat = cv2.getRotationMatrix2D(center,angle,1.0)
result = cv2.warpAffine(image, rot_mat, image.shape,flags=cv2.INTER_LINEAR)

gives this error

Traceback (most recent call last):
File "C:\Users\zeeshan khan\Desktop\opencv\Code\Python\rotate.py", line 13, in <module>
rot_mat = cv2.getRotationMatrix2D(center,angle,1.0)
TypeError: function takes exactly 2 arguments (3 given)

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answered 2016-02-26 03:07:38 -0600

berak
32993 ●7 ●81 ●312

updated 2016-02-26 03:08:26 -0600

np.shape() returns a 3d array, while cv2.getRotationMatrix2D() expects a 2d tuple for the center point.

you have to shave off the 3rd dimension (depth), to make it work:

center = tuple(np.array(image.shape)[:2]/2) # 2d !
rot_mat = cv2.getRotationMatrix2D(center,angle,1.0)
result = cv2.warpAffine(image, rot_mat, image.shape,flags=cv2.INTER_LINEAR)