Single Camera Color Filter Array for Nighttime Visibility
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Solution Overview
Problem
Current driver assistance systems require multiple camera modules to simultaneously implement nighttime pedestrian recognition and lane departure warnings, leading to increased costs and limitations in image quality due to the need for IR pass filters and IR cut filters, which prevent color image representation and object identification in low illuminance environments.
Innovation Solution
A system utilizing a single camera module with a color filter array incorporating IR, R, G, and B filters, along with image processing units for RGB and IR signal extraction, interpolation, and synthesis, to generate lane pattern and pedestrian images in color, enabling simultaneous recognition and display of both images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single camera module is used to implement both NVS and LDWS, then cost is reduced and device complexity is simplified, but image quality deteriorates because the camera cannot simultaneously provide color images for pedestrian recognition and infrared images for nighttime visibility
Solution Approach 1:
The camera module is designed with a color filter array that includes both visible light filters (R, G, B) and infrared filters, enabling a single camera to capture both visible and infrared light simultaneously. This multi-functional design allows the same camera module to perform both NVS (nighttime pedestrian recognition) and LDWS (lane departure warning) functions without requiring separate camera modules for each application.
Solution Approach 2:
The patent combines the filtering functions for visible light and infrared light into a single color filter array structure. By merging the R, G, B color filters with IR filters in a unified array configuration, the system integrates multiple imaging functions (color imaging and infrared imaging) into one camera module, thereby reducing the total number of components while maintaining both imaging capabilities.
2Illumination intensity
If an IR pass filter is installed in the camera module for NVS, then nighttime visibility is improved, but color image representation is lost resulting in black and white images that are difficult for drivers to discriminate
Solution Approach 1:
Instead of using a uniform IR pass filter across the entire camera sensor, the patent implements a color filter array where different regions (pixels) have different filter characteristics. Some pixels are equipped with R, G, or B color filters for visible light detection, while other pixels have IR filters for infrared detection. This local differentiation allows the camera to capture both color information and infrared information simultaneously across different spatial locations.
Solution Approach 2:
The patent adds a spectral dimension to the traditional color filter array by incorporating infrared-sensitive pixels alongside visible light-sensitive pixels. This creates a multi-spectral imaging capability where the camera operates in both the visible spectrum (providing color) and the infrared spectrum (providing nighttime visibility), effectively adding another dimensional layer of information capture.
3Measurement precision
If an IR cut filter is installed in the camera module for LDWS, then visible light imaging is improved, but infrared object identification capability is lost in low illuminance environments
Solution Approach 1:
The camera module uses a color filter array with spatially varying filter properties. Certain pixel regions contain IR cut filters to ensure high-quality visible light imaging for lane detection, while other pixel regions contain IR-pass filters to enable infrared detection for nighttime pedestrian recognition. This local quality differentiation allows the same sensor to serve dual purposes with optimized performance for each function.
4Measurement precision
If multiple camera modules are used to implement both NVS and LDWS functions, then image quality and functionality are maintained, but system cost increases and device complexity increases
Solution Approach 1:
The patent designs a universal camera module that can perform multiple functions (NVS and LDWS) simultaneously through a single device. By equipping the camera with a color filter array that includes both visible light filters and infrared filters, the module becomes multi-functional, eliminating the need for separate dedicated camera modules for nighttime vision and lane departure warning systems.
Solution Approach 2:
The invention merges the functionality of multiple specialized camera modules into a single integrated unit. By combining the infrared detection capability and visible light color imaging capability within one camera module using a unified color filter array architecture, the system reduces component count while maintaining both NVS and LDWS operational capabilities.
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
The system effectively assists driver visibility by providing color pedestrian images and lane pattern alerts using a single camera module, improving image quality and reducing costs, while maintaining the ability to recognize pedestrians and lanes during nighttime driving.
Implementation Method 1
A system utilizing a single camera module with a color filter array incorporating IR, R, G, and B filters
Implementation Method 2
an image sensor for converting the received optical signal into an electrical source image signal
Data Source
AI summary
A system includes a camera module, a processor, and a display drive unit. The camera module includes a lens, a color filter array having an IR filter, an R filter, a G filter, and a B filter, and an image sensor. The number of IR filters is larger than that of G filters, and the number of G filters is larger than that of R filters or B filters. The processor includes a signal extraction unit that extracts an RGB image signal and an IR image signal from an electrical source image signal from the camera module, a lane pattern image data generating unit that generates image data, a pedestrian image data generating unit that generates pedestrian image data. The display drive unit implements image data generated by the lane pattern image data generating unit and the pedestrian image data generating unit through a display.