brightnesslightness

Brightnesslightness is a term used in color science and imaging to denote a proposed composite perceptual attribute that aims to capture both brightness and lightness in a single measure. It is not a widely standardized metric, but appears in discussions of image and display quality where a unified sense of perceived intensity would be helpful for evaluation and processing.

In standard terminology, brightness refers to the perceived intensity of light from a source or scene and is closely related to luminance (often measured in candelas per square meter). Lightness refers to the perceived reflectance of a surface, normalized by the illumination and context, and is commonly associated with perceptual scales such as CIELAB L*. Because brightness and lightness respond differently to illumination, adaptation, and surrounding context, a brightnesslightness value attempts to blend these influences into one perceptual impression.

Measurement and computation of brightnesslightness would typically rely on a combination of luminance data and a perceptual reflectance estimate. A practical approach might use luminance Y (or a gamma-corrected signal) to represent brightness together with a lightness estimate (such as L* or a model-based reflectance cue) and combine them through a function or learned model. The goal is to produce a single value that tracks human perception across common viewing conditions.

Applications for brightnesslightness include display calibration, high dynamic range imaging, photography, and computer vision, where a unified perceptual metric can simplify quality assessment. Challenges include lack of standardization, dependence on adaptation and scene content, and variability across devices, cameras, and viewing contexts. See also brightness, lightness, luminance, and color appearance models.