The Research Of Processing And Recoginzing About The Scanned Engineering Drawing

Engineering drawing vectorization is the process of processing the scanned image and recognizing the graphic objects and finally, generating the vector format CAD file.Vectorization is the foundation of the activities of reusing old drawing and the automatic interpretation of engineering drawing. Therefore, vectorization has high systematic learning and application value. This paper has carried on the research concentrated on scanned image processing and recognition method in engineering drawings.This paper stands on constitute essentially of files and succeed in reading and basic operations using basic methods such as moving, scaling, rotate etc. After carefully analyzing the characteristics of displaying image in the OpenGL's entironment, this paper resolves that left or bottom boundary of displaying image can't overstep the view window, and achieves image part observation.In the research of image processing, this paper clears away noises to lift the image clarity aimed at the noise arisen in engineering drawing by means of mean filtering and medium filtering etc.Then, segments image with the best binarization threshold found by calculating the between-class variance to get useful information and prepare for image recognition.The Raster/Vector Mixed Editing is introduced in this paper. Based on this technology, the raster-formed geometric entities can be vectorized directly from raster image by simple interactive picks. In this paper, we study a new approach to pick raster-formed geometric entities: Firstly, the proposed algorithm sparse traces geometric entities and gets positions of intersecting points by analyzing varieties of the entity's length in radial direction. Then the picked raster-formed geometric is erased. At last, fills the quadrangle decided by the intersecting points.After analyzing experimental results, we can see the proposed approaches in this paper have a good processing effect and higher correct picking rate for raster-formed geometric entities. Also they have good anti-noise ability, especially for the case where the picked entity is intersected with many other entities.