Image Processing Device Adaptive White Balance Color Extraction

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Solution Overview

Problem

Existing image processing technologies face challenges in correctly extracting a color region of a specific color due to the effects of varying light sources, particularly low color temperature light sources like tungsten lamps, which can incorrectly identify achromatic regions as the target color, requiring extensive pre-prepared threshold adjustments.

Innovation Solution

An image processing device and method that estimates the color temperature of the light source and performs adaptive white balance adjustments, allowing for the extraction of specific colors regardless of the light source's color temperature, using a color temperature estimating unit, white balance adjusting unit, and color region extracting unit to apply second white balance adjustments even outside predetermined ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If threshold values of luminance signal and color signal are changed depending on color temperature information, then color region extraction accuracy is improved, but device complexity and information preparation requirements increase

Engineering Contradiction:
Improvecolor region extraction accuracyVSAvoidinformation preparation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs self-service by automatically estimating color temperature from the image signal itself and using this estimation to dynamically adjust white balance and extraction thresholds, eliminating the need for external color temperature measurement devices or manual threshold preparation for different lighting conditions

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes parameters dynamically by adjusting white balance and extraction thresholds based on the estimated color temperature, allowing the same extraction algorithm to adapt to different lighting conditions without requiring pre-prepared threshold sets for each color temperature

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If white balance adjustment is performed based on estimated color temperature, then color extraction accuracy is improved, but processing time increases

Engineering Contradiction:
Improvecolor extraction accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary action by estimating color temperature and performing white balance adjustment before color region extraction, ensuring that the extraction process works on already corrected color data, which improves accuracy without requiring complex post-processing adjustments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The white balance adjustment unit serves multiple functions: it corrects color casts for general image processing and simultaneously prepares the image for accurate color region extraction, eliminating the need for separate correction steps

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If second white balance adjustment is applied for color region extraction, then extraction accuracy under varying light sources is improved, but device complexity increases

Engineering Contradiction:
Improveextraction reliability under varying light sourcesVSAvoidwhite balance adjustment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system implements dynamics by providing two different white balance adjustment modes (first and second) that can be dynamically selected based on whether color region extraction is required, allowing the system to optimize between speed and accuracy depending on the operational context

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2493200B1Image processing device and image processing method
Publication Date: 2020.01.22 SONY GROUP CORP
  • EP2493200B1 patent drawingFigure 1
  • EP2493200B1 patent drawingFigure 2
  • EP2493200B1 patent drawingFigure 3~4

AI summary

An image processing device includes a color temperature estimating unit configured to estimate a color temperature of a light source in imaging, a white balance adjusting unit configured to perform first white balance adjustment in which white balance of an image signal is adjusted on the basis of the estimated color temperature when the estimated color temperature is within a predetermined color temperature range, and perform second white balance adjustment in which the white balance of the image signal is adjusted on the basis of the estimated color temperature even when the estimated color temperature is not within the predetermined color temperature range, and a color region extracting unit configured to extract a color region of a specific color by using the image signal to which the second white balance adjustment is applied.