The Design And Implementation Of Object-Oriented Annotation Database

Annotation as a very important language of the map, is an indispensable means of expressing the map information in Computer-aided cartography and GIS. The map without annotations can just tell us the spatial location of the surface features. It can not express the surface features'name and characteristics in quality and quantity. Therefore, almost every spatial objects in the map has a annotation for expressing its characteristics, levels and numbers. So the number of the annotations in a map is very large.By comparing the software of Computer-aided cartography and GIS used frequently, we can get that the functions of annotation provided by these software are very clumsy and the operation is very complicated. Especially some foreign software can not satisfy the standard mapping requirements, such as the left oblique fonts marking water and the shrug fonts marking mountains can not be achieved. In addition to the annotation of geological code used by the geological industry, these software is helpless.To solve the problems above, this paper studies the following aspects, and gives the corresponding solutions:1) To achieve standardized annotation rendering, the paper introduces the concept of sub-type. By sub-type annotation rendering mode, we can achieved the target of the standardized annotation rendering in a layer using a variety of annotation styles.2) The author will build the standardized annotation database. After analyzing and discussing in detail how to realize the annotations'classification and the styles'definition in the standard cartography specification, the author builds a standardized annotation database to achieve the annotations'storage and management in relational database.3) By researching the TrueType technology, the author has solved the problem which the existing software can not satisfy the standard mapping requirements, such as the left oblique fonts ,the shrug fonts and the font issues which a annotation string include two or more fonts.4) The author designs the object-oriented storage structure to solve the problem that the annotation and the attribute are stored in different files and the management is not convenient. What's more, the author develops the dynamic link library based on the ArcMap platform to achieve the design criteria of calling the annotation database in different platforms.