I want a translucent PNG overlayed on top of my screen (above all windows). I'm using this to mark a visible region while streaming.
So far I've figured out that
qiv -transparent filename.png will add a mask to the window, but it's a boolean mask. I don't get translucent fading with the alpha channel.
I know several effects have opacity, and I can sent window opacity, so I'm hoping there's some way to display an image that way.
What program, tool, or widget can I use to blend an image onto the top of the desktop?