metricsluminance

Metricsluminance is a term used in digital imaging and display engineering to describe a composite metric intended to quantify perceived brightness in images and video. The term is used primarily in research and industry discussions to distinguish physical luminance from perceptual brightness.

In practice, metricsluminance combines a physical luminance source, typically the scene luminance Y or the image's luminance channel, with a perceptual weighting function that models human sensitivity to brightness across luminance levels and spatial details. The outcome is a scalar brightness score or a per-pixel luminance map that can be fed into quality metrics or optimization routines. In emerging literature, the approach is described as mapping physical luminance to a perceptual scale that better aligns with viewer experience than raw luminance alone.

Several implementations exist. Some apply gamma correction and tone mapping to convert physical luminance to perceptual luminance; others compute a weighted average over the image with weights reflecting contrast sensitivity and local adaptation. For video, temporal components may be included to track brightness consistency over time. For practical use, the method of weighting, normalization, and whether temporal information is incorporated vary by application.

Metricsluminance is used in image and video quality assessment, display calibration, and automatic exposure or HDR tone-mapping pipelines. Because definitions vary, cross‑comparison between systems requires clear specification of the perceptual model and normalization. It is not standardized across the industry, and researchers continue to explore how best to align the metric with human brightness perception.

Related concepts include luminance in color spaces, the Y channel in XYZ and sRGB, perceptual weighting, tone mapping, and standard image quality metrics.