Is speed an issue?
What about stretching the picture to twice the real size, then draw almost black scanlines to every second line, then stretch the picture back to original size. Could result in interesting effect, especially if you'd give scanlines some randomness.
Don't know if stretching in B+ is up to the task, though.
What about stretching the picture to twice the real size, then draw almost black scanlines to every second line, then stretch the picture back to original size. Could result in interesting effect, especially if you'd give scanlines some randomness.
Don't know if stretching in B+ is up to the task, though.