Arc segmentation from complex line environments-a vector-based stepwise recovery algorithm

Accurate arc segmentation, essential for high level engineering drawing understanding is very difficult due to noise, clutter, tangency, and intersections with other geometry objects. We present an application of a generic methodology for recognition of multicomponent graphic objects in engineering drawings to the segmentation of circular arcs. The underlying mechanism is a sequential stepwise recovery of components that are segmented as wire fragments during the sparse pixel vectorization process and meet a set of continuity conditions. Proper threshold selection and consistent checking of co-circularity of the assumed arc pieces result in an accurate arc segmentation method.