Research of online automatism identification algorithm based on image character sequence look-up table
Han Yue-ping, Yan Han, Ruihong Li · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2008
This paper proposes an effective approach for online inspecting and recognizing the assembly structure inside three-dimensional objects using multiple views technique and X-ray digital radiography system. During the offline study process, the paper obtains a gray image sequence of a standard sample in multiple circumferential orientations. Utilizing the idea of classifying identification, the paper locates and extracts different characters of different parts in each image of the sequence and establishes corresponding character sequence libraries. In online detection stage, the program finds the optimum solutions to all different target parts in the library with bisearch method and carries out exactness image matching with correlation coefficient weighted of multi-character via Bayes decision. Aiming at the issue of some objects may be occluded by others in a scene, the paper puts forward to rotate the product some certain angles and re-match. Furthermore, the paper analyzes the relationships of misjudgment ratio with product assembling tolerance, the size of target part and identifying velocity. Based on this approach, the first domestic X-ray automatism detection system has been developed and it is successfully applied in online detecting some axis symmetric products which assembly structures inside are complex.