Towards spectral prediction of 2.5D prints for soft-proofing applications

Soft-proofing, the representation of a final print on a display device, is a valuable tool only if the representation corresponds closely to the phenomena involved in the printing process. In a previous work, we employed a color prediction model (CPM) based on the four-flux theory and the optical characterization of the inks used by a 2.5D printer. We were able to predict accurately reflectance and transmittance of ink slabs of different thicknesses for the primary colorants of the Oce High Resolution 2.5D printer. Because it works under any illumination and does not require preliminary measurements (unlike most CPMs), our four-flux model is appropriate for soft-proofing strategies. In the present work, we take our model to the next stage to make the color prediction of relief prints even more general. Using only the primary colorants, we simulate the reflectance and transmittance colors of ink mixtures at different thicknesses. Then we print a hard-copy proof to measure their reflectance and transmittance to assess our model. We achieve satisfying results as the color difference is below two CIELAB AE94 units whatever the ink mixture and the thickness.