Research On Hand-drawing Geometrics Recognition

Hand-Drawing graphics are also known as sketches.It's a common way to express designer's design intent when they are in the conceptual design stage.And provide designers with a platform to display them thought and creative works.The fuzziness of sketches information and user's arbitrary input hindered the development of sketch recognition techniques.With computer software and hardware performance continues to improve and the development of computer graphics,pattern recognition,artificial intelligence and human-computer interaction technology.Many institutions have done a lot of research on sketch recognition both home and abroad at present.And there have been many sketch recognition approaches.Such as the approach based on stroke and graphic unit and the approach base on statistical geometric features.This article does some deeply research on theories and techniques of sketch recognition about geometrics and designs a function model system.The research bases on the geometric characteristics.The model system provides a function about drawing a geometric with hands.And recongnises geometrics with the approach based on graphic unit.The graphic unit includes line,ellipse,elliptic arc,circle,circular arc.First,the system splits the stroke into graph unit according to the features of the stroke from the stroke group after drawing a geometric.It detects features from the sample points according to the stroke curve and speed information and using the scale space method.Second the system make a judgment about graph unit is a line? And it recognises non-linear graphic unit with the theory of conic invariant.Third the system detects the features of the whole sketch according to the relationship among graphic units.Such as the number of graph unit,closed, convex-concave characteristics etc.Then recognises sketch with the theory of the structure pattern recognition.Lastly the system adjusts the recognized sketch along the adjusting rules and displays it.The author develops a system about the sketch recognition on geometric and confirms the recognition algorithms in this article.We also analyze the recognized result.The results prove that:our system has a high speed and accuracy.Our system has some restriction.But some of the algorithms have also reference value for other domains sketch.