Study On Raster To Vector

With the development of computer technology, many CAD softwares are applied widely. At present, most systems of mechanical design and others are accomplished by computer aided design. However, obtained images information is raster information whose data are large because it is need to conserve the data of every pixel. In order to cut down image information, it is necessary to convert raster to vector.The paper mainly discusses vectorization based on thinning of line drawing. Firstly, gray image changed into binary image. Then, noise and stub burr is removed by using basic operation of mathematical morphology—dilation and closing operation. In the course of thinning to target image, the arithmetic of suited cyclostyle is adopted, which prevents the terminals and the acnodes from losing and reducing effectively time in doing so. In order to insure integrality of lines and decrease offset of crossing points, the rule of inertial tracked is used to deal with complex crossing points. Based on the original thinning arithmetic, combine sparse matrix with vectorization of chain code traced, the storage of data is decreased and the efficiency of storage is improved.Image mainly made up of lines has satisfying result after fitting by line, the image that has conic, completely fitting by small lines leads to some difference between the raster and vector. In order to improve the veracity of vectorization, the vectorization of conic is realized by means of curve fitting in this paper.