The color appearance of curved transparent objects

Area of Science:

• Visual perception
• Color science
• Material properties

Background:

• Previous research on transparent objects primarily used flat filters, neglecting complex visual phenomena like caustics and specular highlights.
• Understanding color perception in transparent materials is crucial for fields ranging from computer graphics to material science.

Purpose of the Study:

• To investigate color perception of curved transparent objects using color-matching experiments.
• To evaluate the applicability of existing models (convergence, RMC, RSD, robust ratio) developed for flat filters to curved transparent objects.
• To identify key factors influencing color perception and perceived clarity in curved transparent materials.

Main Methods:

• Conducted color-matching experiments with curved transparent objects and various stimuli (uniform patch, flat filter).
• Instructed observers to match either the object's color or the tinting dye's color.
• Applied and compared four established models (convergence, RMC, RSD, robust ratio) to observer data.

Main Results:

• Observer matches deviated from statistical measures (mean, mode, saturation) of the stimuli.
• Brightest regions of objects captured chromaticity but not lightness of patch matches.
• Modified convergence model showed applicability to curved objects; RMC and robust ratio models generalized better than RSD.
• RMC model demonstrated the strongest predictive power for perceived color.

Conclusions:

• The ratio of means (RMC) is a significant factor in determining perceived color for curved transparent objects.
• The ratio of standard deviations (RSD) appears correlated with the perceived clarity of glass objects.
• Existing models, particularly RMC, can be adapted to explain color perception in more complex, curved transparent materials.