Previous work has shown that tone reproduction characteristics of halftone images can be modeled with knowledge of the probability function P, for light to reflect from the paper between the halftone dots after having entered the paper between the halftone dots. In the current report, experimental measurements of the micro-reflectance, R[p], of the paper between the dots is measured as a function of dot area fraction, F, and used with the model to calculate experimental values for P versus F. It is then shown that the model can be modified to account for inks that have significant scattering. The model is shown to fit data on halftones printed with electrophotography toner which is highly opaque. In addition, the model is further modified to account for the effects of the non-sharpness of the edges of halftone dots. Using both of these effects, the model is shown to fit well with measured data from a variety of AM and FM halftones printed at different resolutions with different colorants. In addition, the model is shown to fit experimental data on the tone reproduction characteristics of a continuous tone, electrophotographic, office copy machine.
Department, Program, or Center
Chester F. Carlson Center for Imaging Science (COS)
The Journal of Imaging Science and Technology 43N4 (1999) 359-364
RIT – Main Campus