Based Tablet Gesture-assisted Drawings Vector System

Engineering drawing vectorization (EDV) is an important research field in image processing. An engineering drawing vectorization system aims to understand and extract the graphic objects in a raster image and transfer them into a commercially available CAD files format that is reusable for future designing and documentation. Clearly, research efforts to improve the efficiency and accuracy of the vectorization procedure are of theoretical and practical importance.Traditional EDV systems place their emphasis on algorithm designing which try to handle all kinds of drawing components with a same strategy before the procedure of human guided revision. The results of such mechanisms are not satisfactory both in efficiency and in vectorization accuracy. This thesis emphasizes its research in the following issues.(1) We reconstruct the vectorization process by employing a digital panel gesture guided arc vectorization procedure before automatic vectorization procedure started. The embedded interactive procedure takes the advantages of a digital panel's elasticity in pointing and drawing by designing a series of hand gesture to guide the computer for complicated arc picking and vectorization. With this method, all arcs that are prone to error in automatic vectorization can be handled accurately. Since arcs are very few in amount in comparison with line segments in an engineering drawing, this procedure is not time consuming. After human guided arc removing, the remained line segments can be vectorized easily because of the removal of arc components.(2) The thesis first deals with dedicated image deflection correction so that most of the line segments in a scanned drawing image can be reverted into it horizontal or vertical origin. A image deflection correction algorithm is purposed. By accurate deflection correction, the line segments can be vectorized efficiently and accurately.(3) A prototype system for engineering drawing vectorization is implemented which integrates the purposed procedure and methods discussed in this paper.