Recognition Of Hand-drawn Schematic

Intelligence sketch technology is that it uses CAD and artificial intelligence under the computer environment, achieve computer's sustain in early design period. It's extending for CAD technology. On-line recognition is a branch of pattern recognition and computer vision, and plays a very important role in Intelligence sketch technology. It studies the methods and techniques to recognize a sketch as it is drawn using a digitizer or an instrumented stylus.With the rapid growth of the computer technology and its widespread acceptance to the society, this research draws much more attention recently, many research teams devote to this complex task which covers a broad field. Aiming at the defects of the existing methods, a study on developing an effective recognition method for the freehand sketches electrical diagrams is performed in this dissertation.In this thesis, we mainly study the method for on-line recognizing the freehand sketching electrical diagrams for the basic primitive shapes, combined primitive shapes and circuit symbols. The primitive shape is classified and defined based on the geometry characteristic. First, we recognize Basic primitive shapes into line, fold-line, ellipse, circle, elliptic arc and circular arc. Then, we adopt the Inner-primitive shape regularization and Inter-primitive shape regularization to recognize the combined primitive shapes. Last, we get the on-line recognizing the freehand sketching electrical diagrams according to the circuit symbol by SRG matching. The freehand sketch recognition system is developed in the above method and confirms our algorithms to be serviceable and extensible.