Details:
Summary:
Gray-component replacement (GCR) is routinely available on a variety of graphic arts color separation scanners made by different manufacturers. Many of the algorithms associated with the computation of GCR have been derived from the use of the Neugebauer equations. As has been reported by Johnson and Jung, however, each of the various scanner manufacturers utilize a different combination of approaches to produce their specific GCR effect. Questions have arisen concerning differences in color and tone characteristics and how differences, if any, are propagated through the reproduction chain. No single work is available comparing each of the many GCR/UCA scanner outputs with one another. Results of data obtained by the author for the 3M Company from studies conducted independently and also under the auspices of the GCR Study Group of the Graphic Communications Association have been reviewed. The work represents an attempt to facilitate an understanding of GCR.