|
Hi Randy, The subject scan is a RGB scan of a green sepia tone color image. If a RGB scan is made of a pure grayscale negative, slide or photo I would agree with your statement regarding channel values representing image density. No color has been introduced nor recorded. I believe sensor imbalance is not an issue for my workflow. Converting a RGB image from grayscale gives you three distinct channels to look at for deciding which channel might give you the best grayscale result if your intent is to move to a grayscale or sepia image, which in our workflow is a Duotone (Black and a color like yellow). From that Duotone image I convert it to a CMYK image for print. Most of what I see and work with in this manner are images may have started as a gray image but became something else either from age, deterioration or manipulation. I have found actual sepia tone images can be improved by deleting 2 channels, convert to grayscale and adding the sepia tone back with Photoshop. I find many times artifacts and noise can be removed by using the RGB channels. The Quincy book image I alluded to in an earlier post was among the dramatic change I ever saw. It was a RRPC and when the RGB channels were examined independently, the post office indices disappeared. The equivalent of a 21-step gray wedge is incorporated in the IT-8 color target we use to color manage all of our scanners, monitors and main color printer. It is the only way WYSIWYG, what-you-see-what-you-get, works for accurate color printing. We generate a fresh ICC color profile about every 7-10 days across all equipment yielding a delta of less than 1.0. Sorry if the choir is bored. Randy Danniel __._,_.___ Posted by: milepost206@mchsi.com __,_._,___ |