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Jitter Matrix re-shaping/transform?

December 7, 2006 | 6:58 pm

Your best bet is to use opengl and a textured videoplane. It’s the
most intuitive interface for doing this kind of thing. As for
jit.mxform2d, the parameters are a projective transformation in 2D
with the 3rd column in the help patch the homogenous coordinates,
upper left 2×2 tdiagonal the scale factor, the left 2 cells of the
lower row as the translation, and the upper left 2×2 matrix the
rotation matrix.

wes

On 12/7/06, Valentin wrote:
>
> Thanks for responding, Jean-Francois :-)
>
> I guess a good way to envision what I want is to give an example :
>
> Lets say that I want to take a normal 4:3 or 16:9 quicktime movie, and project it so that it fits prefectly on a trapezoidal scrim.
>
> (i.e. top and bottom parallel, but top maybe 2/3 or so the width of the bottom) I don’t want to just crop or mask the image, i want to distort it in jitter to fit the trapezoidal shape of the surface.
>
> I did look at mxform2d – but the docs don’t give any useful examples of how to use it to achieve any particular transformation of the image.. I could try to dig into the math – but it would be great to know if there is a simple way to understand what that function really does :-)
>
> Thanks!
>
> – Valentin
>
>


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