Composite X marker detection and recognition

In this paper, a Tri-X composite marker and its corresponding detection and recognition algorithm are proposed. At first the Hessian matrix based X point detector is improved by introduction of symmetry test, which can decrease non-X points significantly. Then two types of Tri-X composite marker are defined. The corresponding detection algorithm is proposed based on the definition and the eigenvector directions of X points. The stereo match of Tri-X composite markers in binocular vision images and its recognition in space are also discussed. The physical experiment results show that the proposed methods for detecting, match and recognition of Tri-X composite marker are effective.