[PD] Keystone correction

[Charles Goyard]

Hi list,

this is very basic, in fact so basic no one ever asked it seems :)

I need to correct the trapezoidal/keystone deformation of a video. The
beamer I use can't correct enough, so I need to do that with GEM. I
heard of a keystone library but could not find it.

I tried various rotate/scale/translate without getting good enough
results.

So I thought I could have a polygon with a texture mapped on it, and the
stretch the corners. The problem I have is that my patch is as follows:

[pix_image test.png]
|
[pix_texture]
|
[circle 4]

(The circle is used to make a mask so the video boundaries are round.)

Adding a polygon after the circle does not seem to work.

Any advice welcome.

-- 
Charlot