> From: Preston Earle > > I don't believe I'm confusing bit depth and resolution, I'm probably > just not explaining myself very well. I'm trying to say that if a > scanner can't (or at least "doesn't") scan adjacent pixels of uniform > color as identical values in 8-bit precision, it doesn't matter what the > other eight high-bits are. I don't have a tool to report 16-bit pixel > values, but the 1x1-pixel point-source eyedropper in Photoshop shows > *no* identical 4-pixel squares in a 2820ppi scan from my ScanDual II. > For example, in an area where the pixels should be the same color, four > adjacent pixels have values of 222r201g178b, 220r200g175b, 222r201g176b, > and 200r200g175b. When these "combine" to make a print dot (or some > other visible whatever) the average is 221r200(or201)g176b. If we knew > the decimal values represented by the high bits, it wouldn't change the > average. Thus it is irrelevant what the high-bit values are.
That's right. > Maybe at some point in the process the 8th (and 9th, 10th, even 11th or > 12th) bit *is* significant, and there is some "noise" added at some > stage of conversion which eliminates the significance of the high bits. > If so, it's valid to use high-bit data before that conversion. After > that conversion, however, high-bit data is irrelevant. It's > less-than-half-cent data in a dollar world. As I said in another post, it appears to me, at least when scanning slides, that film grain is the main source of noise, so there's no way around that. -- Ciao, Paul D. DeRocco Paul mailto:[EMAIL PROTECTED] ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
