return value matchShapes(contours) [closed]

asked 2016-11-16 07:56:24 -0600

stan123
61 ●2 ●5

I know that the return value of the matchShapes() function is different depending of the orientation of the contour. But I recognized that a twisted contour gets a smaller return value than a not twisted. How can this be?

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Closed for the following reason the question is answered, right answer was accepted by stan123
close date 2016-11-18 07:11:34.049968

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answered 2016-11-17 11:47:43 -0600

essamzaky
583 ●2 ●5 ●18

Here there are two methods you can do

Method1

1-convert contour1 to image using drawContour drawcontours

2-convert contour2 to image using drawContour

3-use find keypoints and feature matching , this method is rotation invariant you can follow the following example Feature Matching with FLANN

Method 2

1-You can extract features for the two contours using rotation invaraint feature such as HuMoments HuMoments

2-Compare the two moments if the distance is small the two objects are similar

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matchShapes() is actually using the L2 distance of Hu moments (under the hood)

berak ( 2016-11-17 12:11:49 -0600 )edit

Thank you very much I tried Method 2 and it worked fine for my problem :-)

stan123 ( 2016-11-18 07:06:55 -0600 )edit

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Asked: 2016-11-16 07:56:24 -0600

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Last updated: Nov 17 '16

return value matchShapes(contours) [closed] edit

Closed for the following reason the question is answered, right answer was accepted by stan123 close date 2016-11-18 07:11:34.049968