Hello.
I have already made Color-separation, Chroma-keying (with GREEN back, but can be any color inculuding BLUE), Contrast Adjusting, Gray-scale conversion, Connected-pixel-Tagging, and other applications in VB6. All with Windows API for fast speed. Your application is simple, and i can do in fast time-frame, probably much lesser than the bid time. Your requirments are clear, we can start ASAP. I will give complete source code, properly indented and documented.
Regards...
Zeeshan