Jitter Matrix re-shaping/transform?


    Dec 07 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 2x2 tdiagonal the scale factor, the left 2 cells of the
    lower row as the translation, and the upper left 2x2 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
    >
    >