Auto White Balancing Using Eigen-Illuminant Projection

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Solution Overview

Problem

Traditional auto white balancing methods in image signal processors are calculation intensive and generally less accurate, failing to effectively remove color biases in captured images.

Innovation Solution

The implementation of an image sensor system that includes a memory for storing eigen-illuminant images, an image sensing module, and an image signal processor. The processor generates chrominance channels, performs homogeneous region segmentation, and projects regions of interest onto eigen-illuminant images to determine gray color pixels, using machine learning algorithms to generate these images from a training set.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional auto white balancing methods are used, then the implementation is simpler, but the calculation complexity is high and accuracy is low

Engineering Contradiction:
Improvewhite balancing accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent pre-generates eigen-illuminant images through machine learning training on a dataset of images captured under various lighting conditions. These eigen-illuminant images are stored in memory and serve as reference templates for white balancing. During actual image processing, the system performs homogeneous region segmentation to identify gray color pixels, then compares these pixels against the pre-computed eigen-illuminant images to determine white balance gains. This preliminary computation approach shifts the heavy calculation burden from real-time processing to an offline training phase, thereby reducing real-time computational complexity while maintaining high accuracy.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If traditional auto white balancing methods are used, then the processing speed is faster, but the color bias removal is insufficient

Engineering Contradiction:
Improvecolor bias removal effectivenessVSAvoidimage processing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces traditional iterative mathematical optimization methods with a machine learning-based approach. During the training phase, the system learns optimal white balance characteristics by processing a large dataset of images under various illuminants. The learned eigen-illuminant images and their corresponding white balance gains are stored for rapid lookup during actual processing. This substitution of heavy mechanical computation with pre-learned models enables both high reliability in color bias removal and improved processing efficiency.

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

3Measurement precision

If machine learning algorithms are used to generate eigen-illuminant images, then the white balancing accuracy is improved, but the memory requirement increases

Engineering Contradiction:
Improvegray color pixel detection accuracyVSAvoidmemory storage requirement
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential white balance information from the training dataset by computing and storing eigen-illuminant images and their corresponding white balance gains. Rather than storing entire training images or complex model parameters, the system extracts and retains only the critical eigen-illuminant representations needed for white balancing. This extraction approach significantly reduces memory requirements while preserving the accuracy benefits of machine learning.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS12217433B2Adaptive auto white balancing
Publication Date: 2025.02.04 CISTA SYST
  • US12217433B2 patent drawing
  • US12217433B2 patent drawing
  • US12217433B2 patent drawing

AI summary

This application describes systems and methods for detecting depth in deep trench isolation with semiconductor devices using test key transistors. An method comprises: capturing, by an image sensor, an image; generating a plurality of chrominance channels by converting the image into luminance-chrominance space; performing homogeneous region segmentation on the plurality of chrominance channels to generate one or more regions of interest in the plurality of chrominance channels; and projecting the regions of interest onto eigen-illuminant images to determine gray color pixels on the image, wherein the eigen-illuminant images are generated via performing a machine learning algorithm on a training set of images captured by the image sensor.