Homography of a Rectangle

asked 2015-09-13 21:39:52 -0500

WebSight gravatar image


I am attempting to map a model to an image. The homography transform seems to be required, however i do not have corresponding features.

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Using colour segmentation, it is possible to get a binary image.

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We know which corner we are viewing which gives us one model point, and that the angle should be 90 degrees.

We could extrapolate the other corner using hough lines....

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I want to use findHomograpy(scene, object, 0) but i am unsure how to find enough points. Use default least mean squares.

Can this be done with two points?

Kind regards,


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you need at least 4 points for findHomography.

while you can extrapolate the top-right point, no way for the missing bottom ones. (w/o knowing the side length)

berak gravatar imageberak ( 2015-09-14 00:42:47 -0500 )edit

does it have texture ? (you could try ORB/SIFT keypoints then, instead of the corners)

berak gravatar imageberak ( 2015-09-14 04:15:50 -0500 )edit