Endoscope Image Processing Dynamic Exposure Ratio Control
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Solution Overview
Problem
Existing image processing techniques for endoscopes face challenges in improving signal-to-noise ratio (SNR) and quantization accuracy, especially in low luminance regions, and often result in uneven image quality due to misalignment of light source boundaries with dark and light regions.
Innovation Solution
The system employs a camera control unit (CCU) with a light amount determining section and an exposure ratio determining section to dynamically adjust the light amount and exposure ratio, using a combination of long and short accumulation pixels for HDR imaging, which allows for optimal control of incident light and exposure times to expand the dynamic range and improve SNR and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light distribution control is performed by adjusting projected light intensity of multiple lighting sections, then dynamic range expansion is achieved, but signal-to-noise ratio and quantization accuracy deteriorate in low luminance regions
Solution Approach 1:
The patent changes the parameter of light amount from multiple discrete levels to a continuous variable that can be precisely controlled. By using a single lighting section with continuously adjustable light output, the system achieves fine-grained light amount control that maintains signal-to-noise ratio while expanding dynamic range through coordinated light amount and exposure ratio adjustments.
Solution Approach 2:
The patent merges multiple lighting sections into a single lighting section, eliminating the boundary problems between regions. This consolidation allows uniform light distribution control across the entire imaging area while maintaining the ability to achieve HDR effects through light amount and exposure ratio coordination, thereby preserving signal-to-noise ratio in low luminance regions.
2Illumination intensity
If multiple light source light amounts are controlled for each region, then dynamic range is expanded, but image quality deteriorates due to uneven lightness at region boundaries
Solution Approach 1:
The patent transforms the control approach from discrete regional light amount settings to continuous light amount control. By using a single lighting section with adjustable light output combined with exposure ratio adjustments, the system achieves smooth light distribution without the boundary artifacts that plague multi-section approaches, thereby maintaining high image quality while expanding dynamic range.
3Measurement precision
If light amount is increased to improve signal-to-noise ratio, then quantization accuracy improves, but dynamic range expansion is compromised
Solution Approach 1:
The patent employs dynamic control of both light amount and exposure ratio as a coordinated pair. Rather than statically increasing light amount, the system dynamically adjusts both parameters based on scene requirements, allowing quantization accuracy to be maintained through exposure ratio adjustments while light amount remains optimized for dynamic range preservation.
Data Source
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AI summary
[Object] To improve an sn ratio and to make the image quality good in addition to the expanding of the dynamic range of an image. [Solution] An image processing apparatus according to the present disclosure includes: a light amount determining section that determines, on a basis of a pixel value of each pixel of an imaged image, on a basis of a pixel value of each pixel of an imaged image, a light amount of the imaged image; and an exposure ratio determining section that determines a ratio of an exposure amount of a long time exposure pixel to an exposure amount of a short time exposure pixel on a basis of a ratio of pixels the pixel value of each of which is saturated, among pixels included in a region of the imaged image.