White-Balance Noise Estimation for Low-Light Image Processing
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Solution Overview
Problem
Conventional image processing technologies fail to consider the influence of white balance correction on noise-induced coloring in low luminance regions, leading to deteriorated image quality.
Innovation Solution
An image processing apparatus that estimates the luminance and color difference components of noise based on both common gain and color-specific white balance gains, determining a luminance and color difference range for applying color suppression processing to suppress noise-induced coloring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large gain is used to enhance visibility in low light environment, then visibility is improved, but noise component increases and dominates in low luminance regions causing coloring and image quality deterioration
Solution Approach 1:
The patent applies different processing strategies to different regions of the image based on luminance characteristics. Low luminance regions are identified and processed differently from high luminance regions, with specific noise suppression processing applied only where needed. This localized approach allows gain to be increased for visibility while preventing noise dominance in specific problematic regions.
Solution Approach 2:
The patent dynamically adjusts processing parameters based on luminance levels and noise characteristics. By changing processing intensity, color suppression strength, and filtering parameters according to local luminance conditions, the system can enhance visibility in dark regions without allowing noise to dominate, thus resolving the contradiction between visibility improvement and noise suppression.
2Object-generated harmful factors
If conventional noise reduction control based on gain is applied, then noise suppression is achieved, but the influence of white balance correction on coloring caused by noise is not considered leading to incomplete noise suppression
Solution Approach 1:
The patent merges noise suppression processing with white balance correction processing into a unified processing pipeline. By combining these previously separate operations, the system considers both gain-related noise and white balance-related coloring effects simultaneously, achieving more complete and reliable noise suppression that accounts for all sources of coloring.
Solution Approach 2:
The patent implements feedback mechanisms where noise characteristics and white balance correction effects are continuously evaluated and used to adjust processing parameters. This feedback loop ensures that the noise suppression processing effectively counteracts coloring caused by both gain and white balance correction, improving overall suppression reliability.
Data Source
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AI summary
There is provided an image processing apparatus. Estimation means estimates a color difference component of noise included in a captured image that has undergone white balance correction. Determination means determines a strength of color suppression processing based on a size of the color difference component of the noise. Processing means applies the color suppression processing to the captured image at the determined strength.