Brightness shifts histogram to right, contrast stretches histogram. Is there any possibility of a gamma correction (stretching middle of histogram while compressing edges)? This operation is incorporated in most image processing packages, and would really help in bringing out the middle tones of a poorly exposed photo.
I might give it a try, although not immediately. What would be a good icon for this action? Please send me a private message with your email so I can contact you if I need a tester.