opencv - Keystone effect -


i have fixed pinhole camera. aim flat panel , take image. tilt flat panel , take image. there way convert pixels real-world coordinates, getting rid of keystoning? matrix that.

i tried going real-world coordinates pixels using https://www.mathworks.com/help/vision/ref/cameramatrix.html throws not trapezoid shape parallelogram. loaded calibration image need directly above chessboard or what?

even so, need convert pixels real-world, there way invert 4x3 camera matrix if valid method?

thanks.

you asking things: removing keystone not require knowing 3d world location of panel. need 3x3 homography matrix mapping "keystoned" version of panel "flat" one.

you can compute homography given minimum of 4 pixel correspondences between 2 images. in opencv use "findhomographymat" purpose.


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