On 9 Sep 2002 21:20:44 -0700, ernestsiu@yahoo.com (Ernest Siu) wrote:

>As subject: how do I alter one part of the screen brightness/contrast,
>for example, only the top left quadurant. Or maybe something like
>making a filter using transparency?

Useful for darkening/sharpening/softening/color-shifting/
odd-shaped-picture-in-picture-effects/whatever anywhere in
the frame, with any shape you want: "image matte", in
"transparency" (make a 4:3-proportion matte in B&W of
anything you want, with soft or hard edges [I use 1440x960
for NTSC DV, with at least a slight edge softening to
remove "jaggies"], for use as a matte on a track copied
and placed on V2 or above, in synch. with the original).