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No. 787: A projective geometry lesson

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A projective geometry lesson

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Permanent URL: https://mezzacotta.net/dinosaur/?comic=787

Strip by: David Morgan-Mar

T-Rex: A homography is a mapping from one projective plane to another.
T-Rex: Perspective distortion is an example.
T-Rex: A homography is uniquely defined by the mapping of any four non-collinear points. It can be represented by a 3×3 matrix, operating on a 3-vector of [x, y, 1] coordinates.
Utahraptor: Hey, T-Rex! I used to be addicted to the Hokey Pokey.
Utahraptor: But I turned myself around.
T-Rex: And that's what it's all about.

The author writes:

I just spent 3 days doing geometrical image processing and OpenCV's wrestling with findHomography method.

Putting my right foot in would be a welcome change.