Autocamera Calibration for traffic surveillance cameras with wide angle lenses
This work addresses the problem of simplifying camera calibration for traffic surveillance systems, particularly for wide-angle and thermal cameras, though it appears incremental as it builds on existing calibration techniques.
The paper tackles automatic calibration of traffic surveillance cameras with wide-angle lenses, using video footage and camera height as input to perform intrinsic and extrinsic calibration via fisheye distortion modeling and vanishing point estimation from vehicle motion, demonstrating effectiveness on both visible and thermal cameras.
We propose a method for automatic calibration of a traffic surveillance camera with wide-angle lenses. Video footage of a few minutes is sufficient for the entire calibration process to take place. This method takes in the height of the camera from the ground plane as the only user input to overcome the scale ambiguity. The calibration is performed in two stages, 1. Intrinsic Calibration 2. Extrinsic Calibration. Intrinsic calibration is achieved by assuming an equidistant fisheye distortion and an ideal camera model. Extrinsic calibration is accomplished by estimating the two vanishing points, on the ground plane, from the motion of vehicles at perpendicular intersections. The first stage of intrinsic calibration is also valid for thermal cameras. Experiments have been conducted to demonstrate the effectiveness of this approach on visible as well as thermal cameras. Index Terms: fish-eye, calibration, thermal camera, intelligent transportation systems, vanishing points