The perception of hazy gloss

Area of Science:

• Computer Vision
• Human Perception
• Material Science

Background:

• Previous gloss perception research focused on single specular components in Bidirectional Reflectance Distribution Functions (BRDFs).
• Complex BRDFs with multiple specular components may offer additional perceptual dimensions for surface reflectance qualities.

Purpose of the Study:

• To investigate the perceptual impact of materials with two specular components, eliciting "hazy gloss."
• To determine if observers can discriminate between single-component and two-component specular materials.

Main Methods:

• Renderings of irregularly shaped objects with single or two Ward specular BRDF components were created.
• Stimuli featured simultaneous sharp and blurry highlights, with identical total specular reflectance.
• Matching, discrimination, and rating tasks were employed with side-by-side object presentations.

Main Results:

• Observers primarily focused on the sharpest reflections in matching tasks.
• Discrimination and rating tasks confirmed observers' ability to differentiate between single-component and two-component specular materials.
• A new perceptual dimension, "haze gloss," was identified, extending beyond strength and sharpness.

Conclusions:

• The visual system likely decomposes specular reflections for "haze gloss" perception.
• Neither existing physical gloss measurements nor kurtosis accurately predict perceived haze gloss.
• Two potential visual processing models are proposed: dual gloss components or a central gloss with a halo.