Automatic Light Source Detection for Color Appearance Prediction

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Solution Overview

Problem

Conventional color appearance models require manual intervention for determining environmental parameter values, such as luminance levels of illuminants, which can be time-consuming and inaccurate, especially when predicting color appearance in different viewing environments.

Innovation Solution

A system and method that detects light sources in images to determine specific parameters for color reproduction, including calculating a degree of adaptation for each pixel, allowing for automatic conversion between high and low dynamic range luminance values, and distinguishing between light sources and non-light sources to accurately adjust color appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual measurement of environmental parameter values is used, then measurement precision can be maintained, but loss of time increases significantly

Engineering Contradiction:

Improvemeasurement precisionVSAvoidloss of time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic light source detection and environmental parameter determination without requiring manual measurement. The computer automatically analyzes image data to identify light sources and calculates chromaticity coordinates, eliminating the need for human operators to manually measure environmental parameters while maintaining accuracy through algorithmic processing

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement processes with automated computational image analysis. Instead of using physical measuring instruments and human judgment, the system uses software algorithms to detect light sources in digital images and automatically determine environmental parameters, substituting mechanical/manual operations with electronic processing

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If manual intervention is used for determining environmental parameters, then reliability can be maintained through human judgment, but productivity decreases due to time-consuming processes

Engineering Contradiction:

ImprovereliabilityVSAvoidproductivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system autonomously performs the complete workflow of light source detection, parameter determination, and color appearance prediction without human intervention. The computer automatically processes image data, identifies light sources, calculates chromaticity coordinates, and applies color appearance models, enabling high-speed processing while maintaining reliability through consistent algorithmic execution

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system performs preliminary detection and analysis of light sources and environmental parameters automatically before color reproduction is required. By pre-identifying light sources and determining their chromaticity coordinates in the captured image, the system prepares all necessary parameters in advance, enabling rapid and reliable color appearance prediction without manual intervention at the time of reproduction

Inventive Principle:

Principle #10Preliminary action

3Loss of time

If estimated or presumed values of environmental parameters are used, then loss of time is reduced, but measurement precision deteriorates

Engineering Contradiction:

Improveloss of timeVSAvoidmeasurement precision

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent replaces estimation and presumption with automated optical measurement through image analysis. The system uses the captured image data to objectively detect light source characteristics and calculate precise chromaticity coordinates through computational algorithms, eliminating subjective estimation while maintaining rapid processing speeds

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the captured image as an intermediary to obtain accurate environmental parameter values. Instead of directly measuring physical parameters or relying on estimation, the system analyzes the optical information already present in the captured image to derive precise chromaticity coordinates and light source characteristics, providing accurate measurements without requiring additional manual measurement devices or time

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8483479B2Light detection, color appearance models, and modifying dynamic range for image display

Publication Date: 2013.07.09 DOLBY LABORATORIES LICENSING CORP

AI summary

Embodiments relate generally to image and display processing, and more particularly, to systems, apparatuses, integrated circuits, computer-readable media, and methods that detect light sources in images to facilitate the prediction of the appearance of color for the images in different viewing environments and/or dynamic range modification based on the light sources (e.g., perceived light sources). In some embodiments, a method includes detecting pixels representing a portion of an image, specifying that a subset of pixels for the image portion is associated with a light source, and determining a parameter for the subset of pixels, the parameter being configured to generate a color in a reproduced image that includes the image portion. In one embodiment, light sources are detected to facilitate converting between high dynamic ranges and low dynamic ranges of luminance values.