Color-difference evaluation for 3D objects

A psychophysical experiment using 3D printed samples was conducted to investigate the change of perceived color differences caused by two different illuminations and sample shapes. 150 pairs around five CIE centers [Color Res. Appl. 20, 399–403, 1995], consisting 75 spherical flat samples, with a wide range covering from small large magnitude, were an Mcor Iris paper-based printer. Each pair assessed twice panel 10 observers gray-scale method in spectral tunable LED viewing cabinet types light sources: diffuse lighting without additional overhead spotlight. The experimental results confirmed that conditions had more effect on difference between complex shapes than 2D objects. for objects similar under only lighting. Current good correlations previous ones 24, 356-368, 1999; J. Opt. Soc. Am. 36, 789-799, 2019] differences, meaning color-difference magnitude shape Considering ten modern formulas, best predictions current data found CAM02-LCD formula 31, 320-330, 2006]. For results, it also formulas below average inter-observer variability, remarkable improvements adding power corrections [Opt. Express 23, 597-610, 2015].