Light Source Spectrum Estimation Using RGB and Multispectral Sensors

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Solution Overview

Problem

Conventional methods for obtaining a light source spectrum using a multispectral sensor result in an integral combination of the light source spectrum, object material reflectivity spectrum, and response function, leading to low accuracy.

Innovation Solution

A method involving an RGB sensor and a multispectral sensor that uses a pre-trained model to determine the probability of a light source type and its spectrum based on input information, allowing for a weighted sum to obtain a more accurate light source spectrum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multispectral sensor is added to a camera to obtain light source spectrum, then the light source spectrum can be used for guiding white balance processing and color correction processing, but the obtained spectrum is an integral result of light source spectrum, object material reflectivity spectrum, and response function, leading to low accuracy

Engineering Contradiction:
Improveaccuracy of light source spectrumVSAvoidcomplexity of spectrum acquisition system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the spectrum acquisition process into two independent parts: (1) using a multispectral sensor to capture the integral spectrum (light source × object reflectivity × response function), and (2) using a trained neural network model to separate and estimate the pure light source spectrum from this integral result. This segmentation allows the system to maintain simplicity while achieving high accuracy by decoupling the measurement function from the analysis function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a neural network model as an intermediary component that processes the integral spectrum data from the multispectral sensor and transforms it into an accurate light source spectrum estimation. This intermediary model acts as a bridge between the raw sensor data and the desired pure light source spectrum, enabling accurate spectrum acquisition without requiring complex hardware modifications.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If conventional interpolation processing is used on multispectral sensor data to obtain light source spectrum, then the processing is simple and fast, but the result is not a pure light source spectrum and accuracy is not high

Engineering Contradiction:
Improveaccuracy of light source spectrumVSAvoiddifficulty of separating light source spectrum from integral result
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces the conventional mechanical/mathematical interpolation processing method with an intelligent neural network-based approach. Instead of using traditional signal processing techniques to estimate the light source spectrum, the system employs a trained neural network model that has learned the complex relationships between integral spectra and pure light source spectra from training data, achieving superior accuracy by substituting mechanical processing with intelligent computation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the processing approach from direct mathematical interpolation to probabilistic estimation through a trained neural network. The model outputs a probability distribution over possible light source types and their corresponding spectra, allowing the system to select the most likely light source spectrum. This parameter change from deterministic interpolation to probabilistic estimation enables higher accuracy in separating the light source spectrum from the integral result.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12518506B2Method for obtaining light source spectrum and device
Publication Date: 2026.01.06 HUAWEI TECH CO LTD
  • US12518506B2 patent drawing
  • US12518506B2 patent drawing
  • US12518506B2 patent drawing

AI summary

A method for obtaining a light source spectrum includes: obtaining first information in a current photographing scene, where the first information includes at least one of a first image generated by a red, green, and blue (RGB) sensor or a light intensity of light received by each pixel on a first multispectral sensor; inputting the first information into a first model to obtain a probability that a light source in the current photographing scene belongs to each type of light source; and determining a spectrum of the light source in the current photographing scene based on the probability that the light source in the current photographing scene belongs to each type of light source and a spectrum of each type of light source.