Halation Detection in Image Capture Apparatus Using Local Shutter Control
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Solution Overview
Problem
Existing camera systems face challenges in suppressing halation, a phenomenon that degrades image quality by causing excessive electrical charges on image capture devices, particularly under low-illuminance conditions like nighttime public road surveillance, where vehicle headlights introduce high-luminance light, leading to reduced visibility of objects like license plates.
Innovation Solution
An electronic apparatus and image capture apparatus that detect halation by evaluating luminance and controlling the irradiation of infrared light, adjusting exposure levels, and using filters to minimize halation's impact on image quality, thereby enhancing object visibility without degrading image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the incident light amount is reduced by controlling the electronic shutter or providing the liquid crystal panel, then the influence of halation is eliminated, but the image quality of the image is degraded
Solution Approach 1:
The patent applies local quality by selectively reducing incident light only in regions where halation occurs (around high-luminance areas) while maintaining normal exposure in other regions. This is achieved by detecting halation regions and adjusting the electronic shutter speed locally, thus eliminating halation influence without degrading overall image quality.
Solution Approach 2:
The patent employs dynamics by dynamically adjusting the electronic shutter speed based on real-time detection of halation conditions. The system continuously monitors the image for halation occurrences and adapts the exposure control accordingly, switching between normal and halation-suppression modes as needed, rather than using a static light reduction approach.
2Object-affected harmful factors
If the incident light amount is reduced to eliminate halation, then halation influence is suppressed, but visibility of the object is reduced due to degraded image quality
Solution Approach 1:
The patent maintains object visibility by applying light reduction only in specific halation regions rather than across the entire image. Objects in non-halation areas retain their original visibility, while halation regions receive targeted exposure adjustment, thus suppressing halation influence without compromising overall object detection capability.
Solution Approach 2:
The system uses feedback by detecting halation regions in the captured image and using this information to adjust subsequent exposure settings. The detection unit identifies halation occurrences, and the control unit responds by modifying the electronic shutter speed specifically for affected regions, creating a closed-loop system that maintains object visibility while suppressing halation.
3Object-affected harmful factors
If the infrared cut filter is inserted into the optical path, then infrared light is blocked, but halation caused by halogen headlights cannot be suppressed because they emit large amounts of infrared light
Solution Approach 1:
The patent replaces the mechanical/optical approach of using an infrared cut filter with an electronic control approach using the electronic shutter. By controlling the shutter speed dynamically, the system can suppress halation from any light source type (including halogen headlights with infrared emission) without the need for physical filter insertion, thus maintaining adaptability to different lighting conditions.
Solution Approach 2:
The system changes the exposure parameter (shutter speed) rather than modifying the optical path with filters. By adjusting the temporal parameter of light capture through electronic shutter control, the patent achieves halation suppression that is independent of the light source's spectral characteristics, making it universally effective against all types of high-luminance lights including halogen headlights.
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
Effectively suppresses halation's influence on image quality, improving the visibility of objects like vehicle license plates, regardless of the light source type, while maintaining image quality by dynamically adjusting exposure and using targeted light control.
Implementation Method 1
an image capture device which receives incident light containing infrared wavelength light
Implementation Method 2
an infrared light irradiation unit which irradiates infrared light onto an object to be imaged
Data Source
AI summary
An electronic apparatus that can enhance the accuracy of detection of halation by taking into account the influence of halation on visibility of an object, and also effectively suppress the influence of halation independently of the type of a light source. An evaluation unit evaluates the luminance of the object based on an exposure level at which image data of the object is acquired. A detection unit detects t halation based on the luminance of the object, a first luminance area having a higher luminance than a first luminance threshold value, and a distribution status of another luminance area which is an area having a lower luminance than the first luminance area and is distributed around the first luminance area.