Video based Vehicle Speed Computation (HAWK)
Paper: | |
Contact: |
“Homography-Based Passive Vehicle Speed Measuring”
Shah et al.
Patent No.: US 8,238,610 B2
Issued: Aug. 7, 2012
The goal of this project is to measure vehicle speeds on US highways by processing the video of moving vehicles captured through a digital video camera. The system was designed to be able to satisfy the following requirements:
- Real-time system
- Use limited resources: (1) Quality of the camera (2) Power of the processing unit
- Robust and accurate
- Exploit existing infrastructure: (1) Bridges over highway (2) Traffic monitoring cameras
Results – Output from the HAWK system
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Side View Videos |
Our video based speed computation system has following advantages over conventional systems:
- Monitors multiple lanes simultaneously – with a single camera
- Uses existing infrastructure – bridges, poles etc
- Passive monitoring – effective against radar detectors and laser jammers
- Low Cost – Cameras cheaper than radar or laser technology
The initial development version of the speed computation system has been developed. It is written in C++ and processes either the recorded video or live video captured via a USB webcam. The system runs on a Windows based Desktop or Laptop running Windows XP or higher. Apart from the GUI (which uses the MFC library), maximum adherence to the ANSI C++ specification has been attempted.
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(a) | (b) |
(a) The main modules of our speed computation system (b) The software components of the HAWK system
The system runs real time on a 2GHz laptop computer, while processing 320×240 resolution video at 15 fps. Under these conditions the system is able to identify and compute speeds for 99% of the vehicles travelling on the highway (including trucks, buses and motorcycles). The accuracy of the system was determined by comparing the speeds with those obtained from a commercially available radar-based speed gun. The mean difference between the speeds was 0.86 mph with a standard deviation of 0.89 mph. This difference was negligible considering the fact that speed gun computes instantaneous speeds while our system computes average speeds.
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(a) | (b) |
(a) The main dialog box of the HAWK application (b) The parameters dialog box of the HAWK system