Clapper-Yule Model On Fluorescent Substrate In Halftone Image

For economy and environment, the ratio of using second fiber is getting higher and higher in modern papermaking. However, much fluorescent substrate is contained in the second fiber, especially fluorescent white agent (FWA). On the other hand, in order to improve paper's white; FWA is used in the papermaking. The FWA can absorb ultraviolet light and change it to normal light, so the reflection of bulk paper is getting higher. This characterization of FWA can improve paper's white and its printing ability。In traditional color predication model, only classical Clapper-Yule model was established on considering multi internal reflection in paper. Theoretically and practically, this model is used well. Though some researchers expanded this model for considering different factors, none of them combined fluorescent effect in paper and this model to obtain a new model. In this paper, the classical Clapper-Yule is studied with considering fluorescent effect. Comparing different expressions in Clapper-Yule model with and without fluorescent effect, one can obtain prediction color with fluorescence brighter than without it. For generalizing the new model, rough substrate is also studied with and without fluorescent effect. Comparing different expressions in rough substrate Clapper-Yule model with and without fluorescent effect, one can obtain prediction color with fluorescence brighter than without it too. Because the classical Clapper-Yule model does not contain physical dot gain, it is studied in the new model. One can obtain prediction color brighter with considering physical dot gain. So if fluorescent effect and physical dot gain are considered coincidently, the deficiency of prediction color darker using classical Clapper-Yule is corrected.