Effects of the retina-inspired light intensity encoding on color discrimination performance

2024-06-30

IEEE International Joint Conference on Neural Network

AI Summary

This study addresses the challenge of color constancy (CC)—the visual system’s ability to perceive consistent object colors under varying illumination—by proposing a retina-inspired center/surround (C/S) Retinex model. The model uniquely integrates the Naka-Rushton (N-R) photoreceptor response function with a double-opponent chromatic representation grounded in classical opponent-color theory, implemented within the HSV color space. Experimental validation was conducted using a variable-color LED setup to simulate diverse illuminants. Results demonstrate that the proposed approach significantly outperforms conventional logarithmic encoding in color discrimination across multiple lighting conditions, thereby confirming the synergistic efficacy of N-R encoding and the double-opponent chromatic plane in enhancing color constancy.

Technology Category

• Cognitive Modeling & Cognitive Systems: Neural Spike Coding
• Computer Vision: Representation Learning for Vision
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Search and Retrieval-Augmented AI: Web learning to rank, online learning, and counterfactual learning for ranking
• User Modeling, Personalization and Recommendation: Fairness-aware retrieval and ranking
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Color is an important source of information for visual functions such as object recognition, but it is greatly affected by the color of illumination. The ability to perceive the color of a visual target independent of illumination color is called color constancy (CC), and is an important feature for vision systems that use color information. In this study, we investigated the effects of the light intensity encoding function on the performance of CC of the center/surround (C/S) retinex model, which is a well-known model inspired by CC of the visual nervous system. The functions used to encode light intensity are the logarithmic function used in the original C/S retinex model and the Naka-Rushton (N-R) function, which is a model of retinal photoreceptor response. Color-variable LEDs were used to illuminate visual targets with various lighting colors, and color information computed by each model was used to evaluate the degree to which the color of visual targets illuminated with different lighting colors could be discriminated. Color information was represented using the HSV color space and a color plane based on the classical opponent color theory. The results showed that the combination of the N-R function and the double opponent color plane representation provided superior discrimination performance.

Problem

• color constancy
• light intensity encoding
• retina-inspired model
• color discrimination
• illumination color

Innovation

• color constancy
• Naka-Rushton function
• retina-inspired encoding
• center/surround retinex
• opponent color theory