Endoscope Color Filter Lattice for High-Resolution Lesion Detection
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Solution Overview
Problem
Conventional endoscope apparatuses face challenges in switching between white light imaging and narrow band imaging methods for accurate detection of lesions in mucous membrane surfaces, particularly in generating high-resolution color images using single-chip image sensors with Bayer filter arrangements, which require interpolation processing to compensate for missing color components.
Innovation Solution
The endoscope apparatus incorporates a light source unit that emits white or narrow band illumination light, an image sensor with a lattice pattern of pixels, and a color filter with a specific arrangement of filters passing red, green, and blue wavelength bands, along with a demosaicing processing unit that selects luminance components and generates color image signals based on the type of illumination, optimizing pixel selection and interpolation for high-resolution image generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-chip image sensor with Bayer filter arrangement is used to capture color images, then the device complexity is reduced, but the measurement precision of color components deteriorates due to the need for interpolation processing
Solution Approach 1:
The patent applies local quality by differentiating the function of specific pixels within the Bayer array. Green pixels are selectively designated as luminance component pixels while blue and red pixels serve as color difference component pixels. This local functional differentiation allows the system to optimize for both luminance precision and color accuracy without requiring a different sensor architecture.
Solution Approach 2:
The patent segments the color image processing into two distinct components: luminance components derived from green pixels and color difference components derived from blue and red pixels. This segmentation allows independent optimization of each component's quality, with luminance pixels providing high spatial resolution and color difference pixels providing accurate color information.
2Productivity
If interpolation processing is performed to generate missing color components in each pixel, then a complete color image can be generated, but the manufacturing precision of the image quality deteriorates
Solution Approach 1:
The patent uses color difference components as an intermediary to achieve high-quality color images. Instead of directly interpolating all missing color components, the system calculates color difference components (Cb and Cr) using blue and red pixels, then combines these with luminance components from green pixels. This intermediary approach preserves more original pixel data and reduces interpolation artifacts.
Solution Approach 2:
The patent performs preliminary calculation of color difference components before final image reconstruction. By pre-calculating Cb and Cr values from blue and red pixels and storing them for later use in combination with luminance data, the system prepares high-quality color information in advance, reducing the need for complex real-time interpolation during image generation.
3Measurement precision
If the number of green wavelength band light filters is increased to improve luminance precision, then the measurement precision of luminance components is improved, but the quantity of blue wavelength band light filters decreases
Solution Approach 1:
The patent changes the functional parameter assignment of different wavelength band filters. Instead of treating all pixels equally, it assigns green pixels primarily to luminance measurement and blue/red pixels to color difference measurement. This parameter change allows the system to maximize luminance precision using green filters while maintaining adequate blue filter quantity for accurate color difference calculation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables high-resolution image capture and display in both white light and narrow band imaging methods, improving lesion detection accuracy and image quality by accurately interpolating color components, thereby enhancing the diagnostic capabilities of the endoscope.
Implementation Method 1
an image sensor having a plurality of pixels arranged in a lattice pattern, each of which is configured to receive light, the image sensor being configured to perform photoelectric conversion on the light received by each of the plurality of pixels to generate an electric signal
Data Source
AI summary
An endoscope apparatus includes: a light source unit that emits white illumination light or narrow band illumination light; an image sensor having pixels; a filter unit arranged corresponding to the pixels and including filters having a filter for passing blue light, and a filter for passing the blue light and one of green light and red light, the number of the filters for passing the green light being not less than half of the number of all the filters of the filter unit, and the number of the filters for passing the blue light being not less than the number of the filters for passing the green light; a selecting unit that selects, from the pixels, a luminance component pixel depending on types of illumination light; and a demosaicing processing unit that generates a color image signal having color components based on the luminance component pixel.