Neuromorphic Dual-channel Encoding of Luminance and Contrast

TL;DR

This paper reviews retinal dual-channel mechanisms that encode luminance and contrast, showing they produce brightness perceptions that are log-linear over a wide range, with implications for neuromorphic systems.

Contribution

It provides an overview of retinal luminance and contrast encoding mechanisms and demonstrates their log-linear brightness response across large luminance ranges.

Findings

Retinal channels encode luminance and contrast separately.

Brightness perception is log-linear over seven orders of magnitude.

Retinal mechanisms inform neuromorphic encoding models.

Abstract

There is perceptual and physiological evidence that the retina registers and signals luminance and luminance contrast using dual-channel mechanisms. This process begins in the retina, wherein the luminance of a uniform zone and differentials of luminance in neighboring zones determine the degree of brightness or darkness of the zones. The neurons that process the information can be classified as "bright" or "dark" channels. The present paper provides an overview of these retinal mechanisms along with evidence that they provide brightness judgments that are log-linear across roughly seven orders of magnitude.