Camera Exposure Timing for Motion-Blur-Limited Object Recognition
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Solution Overview
Problem
Existing camera systems in moving vehicles face challenges in maintaining angular image resolution due to motion blur, which cannot be effectively addressed by increasing image processor resolution alone.
Innovation Solution
A method to determine an exposure time for a camera system that maintains a specified minimum angular image resolution by considering the camera's movement and scene dynamics, using inverse proportionality and probabilistic motion models to stabilize images and ensure sufficient signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If telephoto cameras with high image processor resolution are used to resolve objects at great distances, then the working range and resolution are improved, but motion blur increases significantly when the camera or scene is moving, reducing effective image resolution
Solution Approach 1:
The patent applies dynamics by making the exposure time adjustable and adaptive rather than fixed. The system dynamically determines the optimal exposure time based on real-time motion characteristics (angular velocity ωK) and scene conditions, allowing the camera to adapt its exposure parameters to maintain image quality during vehicle movement. This is implemented through continuous measurement of motion parameters and calculation of exposure time according to the formula t ≤ tmax = (dp × Ra*)/(ωK × 180), where all parameters are adjusted based on current operating conditions.
Solution Approach 2:
The patent changes the exposure time parameter based on measured motion characteristics. By establishing a functional relationship between exposure time and angular velocity (t ≤ C/ωK), the system adjusts the exposure time parameter dynamically to compensate for motion blur. When motion increases, exposure time is reduced; when motion decreases, exposure time can be increased to maintain signal-to-noise ratio. This parameter adaptation resolves the contradiction between needing long exposure for resolution and short exposure to avoid motion blur.
2Use of energy by moving object
If the exposure time is increased to improve signal-to-noise ratio and image quality, then sensitivity is improved, but motion blur increases and angular image resolution deteriorates
Solution Approach 1:
The patent resolves this contradiction by dynamically changing the exposure time parameter based on measured angular velocity. The system calculates the maximum permissible exposure time tmax = (dp × Ra*)/(ωK × 180) and sets actual exposure time accordingly. This creates an optimal balance where exposure time is long enough to achieve sufficient signal-to-noise ratio but short enough to prevent excessive motion blur. The parameter is continuously adjusted as motion conditions change.
Solution Approach 2:
The system implements feedback by continuously measuring the angular velocity ωK of camera movement or scene motion, using this measurement to calculate the appropriate exposure time, and then applying this calculated exposure time in subsequent recordings. This closed-loop feedback mechanism ensures that exposure time always adapts to current motion conditions, maintaining optimal image quality without excessive motion blur while achieving sufficient signal-to-noise ratio.
3Device complexity
If a single camera is used to simplify the system, then device complexity is reduced, but it cannot simultaneously achieve both wide field of view (100°+) and high resolution at long distances
Solution Approach 1:
The patent makes a single camera system universal by enabling it to perform multiple functions that would traditionally require different specialized cameras. Through dynamic exposure time adjustment based on motion characteristics, a single camera can effectively function as both a wide-angle surveillance camera and a high-resolution telephoto camera. The system adapts its exposure parameters according to the required function, allowing one camera to replace multiple specialized cameras while maintaining both wide field of view capability and long-distance resolution capability.
Data Source
AI summary
A method for determining an exposure time for a camera of a camera system that is moving and/or used in a moving scene for automatic object recognition, wherein a specified minimum angular image resolution is maintained. The method includes: determining an effective angular image resolution as a function of the exposure time; determining a maximum permissible exposure time as the exposure time with which the effective angular image resolution takes the value of the minimum angular image resolution; setting the exposure time to a value less than or equal to the maximum permissible exposure time. A camera system is also described.