Ken writes ... > ... I think I understand that the bottom histogram in Vuescan > is the RGB channels, but what is the upper one, and why does > it not clip sometimes when the lower ones do?
It is Ed's best calculation of the "lightness" of a pixel. If I remember correctly, it is weighted to the green channel value, and least weight goes to blue ... I believe you can see a similarity. Weighted green is the most common method for evaluating lightness ... however, since Vuescan's histogram is most commonly used for evaluating the endpoints, black & white, I wonder if equal weighting is more appropriate(?) cheerios ... shAf :o) Avalon Peninsula, Newfoundland ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
