The Approach To Recognizing Map Symbol Based On Rotation-Processing

As we know that the automatic recognition of map symbol is the key technology how to realize automatic digitalization of scanning map. During the recent decade, we have achieved outstanding processes of recognition technology and methods in map symbol and especially in point symbol area by the dedicated work of international experts in this specific field. They have already accumulated lots of mature and fruitful arithmetic, whereas the recognition method of oriented-point symbol by far is still an unsolved problem.The oriented-point symbol is a sub-branch of map point symbol. Compared to standard point symbol, the oriented-point symbol contains direction angle information. However, conventional point symbol recognition technologies rarely take oriented-point symbol into account. Its mainly comes from the existent of angle offset, which many of the traditional recognition technologies no longer apply to the new situation. So we need to recognize oriented-point symbol as an exception individually.On the base of previous research and intensive analysis the characteristic of oriented-point symbol, we bring forward a recognition method on rotation processing. It is a more universal way, not only resolve the problem of automatic recognition in oriented-point symbol, but also unify it in recognition of common point symbol.This dissertation initially discusses the problem on how to realize automatic recognition of oriented-point symbol by means of rotation processing, explore and expand its method and realize the unify of point symbol recognition by method of drawing image data as identifier out of the image sequence in structure twisting, which unable to realize by traditional ways Afterward, we probe into the characteristic of line symbol, directed characteristic of line symbol on the ground of primitive and explore the essential idea of line symbol recognition on rotatiorn processing. By the end of this essay, we evaluate the recognition methods on rotation processing and analysis the development and prospect trends on automatic recognition technologies.