Train wheel edge detection and image object region segmentation

Machine vision based mechanical appearance fault analysis and inspection is getting broad applications in past decades. Train wheel tread damage is a common fault pattern. The precedent step of the routine vision based analysis work is to get an image that includes the wheel surface. In this paper, a wheel curve edge extraction and object region segmentation framework is proposed. Firstly the salient rail line edge is extracted for a previous segmentation step and a sub image is acquired. Then line segment detector is used to detect the lines along the contours. And the wheel and shadow curve edge are approximated by line segments sets. Through certain geometry rules, the two edge lines are extracted. Finally the wheel object region is extracted perfectly and accurately.