Real-time object recognition using a modified generalized Hough transform

A technique for real-time object recognition in digital images is described. On the one hand, our approach combines robustness against occlusions, clutter, arbitrary illumination changes, and noise with invariance under rigid motion, i.e., translation and rotation. On the other hand, the computational effort is small in order to fulfill requirements of real-time applications. Our approach uses a modification of the generalized Hough transform (GHT) to improve the GHT's performance: A novel efficient limitation of the search space in combination with a hierarchical search strategy is implemented to reduce the computational effort. To meet the demands for high precision in industrial tasks, a subsequent refinement adjusts the final pose parameters. An empirical performance evaluation of the modified GHT is presented by comparing it to two standard 2D object recognition techniques. (C) 2003 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.