Study On Raster Vector Conversion

Automatic vectorization of the engineering drawing is one of the key technologies in CAD field. The purpose of this paper is to transform black-white raster image into vector storage after preprocessing and vectorizing steps.An improved vectorization algorithm is presented after theoretically analyzing and comparing different vectorization methods. The prominent features of this algorithm are as follows: correctly dealing with cross and corner by adopting junction recovery process which adjusts the length of tracking step according to the demand; compressing the amount of data, editing image and drawing new graph more easily by extracting coordinates of the center, radius, start point and end point of circle, avoiding the gap of circular arc; ensuring the critical points in the image as less as possible. The results show this vectorization algorithm can make good vector images.