Calibration of Robot’s Omnidirectional Vision System
Name
Janno Jõgeva
Abstract
The aim of this paper is to present a method for camera calibration. The actual implementation of the calibration process itself is not included in this paper, the solution is only theoretical. The camera calibration is considered in this paper in the meaning of spatial calibration and not in the sense of photometric camera calibration. The calibration problem arose in the robotics competition Robotex. The exact location of objects on a certain plane needs to be estimated by the robot in real-time. This means that there is a need for mapping between pixels and real world distances.
This paper presents a set of existing methods for solving this camera calibration problem.
The test data is generated using POVRay ray-tracing software. This enables predictable test cases for the software. A white square sheet of paper is used as the calibration pattern. A simplified version of W. Sun’s [41] corner detection algorithm is implemented to extract the location of the calibration pattern from an image. After the corners have been extracted, a method based on bilinear interpolation is proposed to calibrate the camera. The information that the calibration pattern is a square in the physical world is used in the calibration method. The proposed method suggests that using more frames increases the accuracy of the calibration. In order to improve the accuracy, the image is divided into subsections that are assumed to have a bilinear transformation from the physical world to the observed image.
The next research in this field should implement the suggested method to verify
it’s accuracy.
Graduation Thesis language
Estonian
Graduation Thesis type
Bachelor - Computer Science
Supervisor(s)
Sven Laur
Defence year
2012