java - How exactly do I use OpenCV and homographies to undo perspective warp? -


i need use java , opencv process shown on http://en.wikipedia.org/wiki/perspective_control know 4 points of trapezoid are, , need them square up. i've heard need use homography , warpperspective command, don't know parameters these use. don't know how employ them, need use them. can explain this? i've never done this, starting bare minimum awesome. i'd world of computer vision having me out appreciated.

their 2 methods doing this:

1) geometric warping use perspective geometry create h matrix. or

2) using feature matches create same h matrix.

opencv has nice function called findhomography (which second method) takes in 2 arrays. both arrays should matching features 2 different images.

once have h matrix creating warped image easy , can call warpperspective store in matrix imshow see.


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