Reasoning About Camera Positioning Relative To Rectangular Patterns
David H. Kite, Michael J. Magee · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1989
An algorithm to determine the three-space position and orientation of a robot camera relative to a rectangular shaped mark of known size has been developed. In contrast to similar research, this algorithm does not require that a priori constraints be placed on the original position or orientation of the camera relative to the mark. Given the image plane positions of at least three vertices of the mark, the two projected diagonals of the mark are isolated and processed in turn to find the 2d position of the camera in the plane that contains the diagonal and the line connecting the centroid of the mark and the focal point of the camera. The 2d results are then combined using heuristics to determine the unique three-space position and orientation of the camera relative to the rectangle. If fewer than three vertices are visible, camera repositioning parameters are computed such that relational determination can be achieved from a subsequent image. Results of camera position determination and an analysis of associated errors are provided.