[Gimp-user] Masking for Contrast Control - Can this be done in Gimp?

[David Gowers]

On Wed, Apr 1, 2009 at 10:53 PM, Olivier Lecarme <ol at olecarme.homelinux.net>
> Placing the top layer in divide mode is also very useful. Also try
> Overlay or Soft light. All this is much simpler than the method
> suggested by the original site, which seems an overkill.
Agreed. If I was doing this, I would not use channels at all, and I'd
hardly use layers.
I would:
 1. Edit->Copy the image
 2. Enter QMask mode
 3. Edit->Paste, and Anchor
 4. Colors->Invert
 5. Leave QMask mode
 6. Edit->Copy
 7. Edit->Paste
 8. Convert the floating layer to a normal layer
 9. Adjust the new layer
 10. Merge or flatten when done.