Estimating the glossiness transfer function induced by illumination change and testing its transitivity

Area of Science:

• Visual perception
• Computer graphics
• Material science

Background:

• Surface glossiness perception is influenced by object reflectance and scene lighting (light field).
• Understanding how perceived glossiness changes across different light fields is crucial for realistic rendering and visual science.

Purpose of the Study:

• To determine the mathematical form of the glossiness transfer function between different real-world light fields.
• To test the transitivity of glossiness perception: if glossiness transfer from light field 1 to 2 and 2 to 3 is known, can it predict transfer from 1 to 3?

Main Methods:

• Four observers compared the perceived glossiness of surfaces under two distinct real-world light fields.
• Data was used to estimate a transfer function modeling glossiness remapping between light fields.
• The transitivity property of these transfer functions was statistically evaluated across sets of three light fields.

Main Results:

• Observers' estimated glossiness transfer functions were best modeled by a linear function.
• Three out of four observers demonstrated the expected transitivity pattern in their glossiness perception.
• The deviation from transitivity for one observer was minimal, accounting for less than 12.5% of the gloss range.

Conclusions:

• The perceived glossiness transfer function between different light fields can be approximated by a linear model.
• Glossiness perception generally exhibits transitivity, suggesting predictable relationships across varying lighting conditions.
• Individual differences in glossiness perception exist but appear to be relatively small within the tested range.