利用缓冲区动态生长模型进行岛屿自动选取

针对当前岛屿自动综合算法使用的Voronoi图在表达岛屿密集程度时存在缺陷，从而导致选取结果难以满足生产实际需要这一现状，提出一种利用缓冲区动态生长模型进行岛屿选取的自动选取方法。首先，从原理上分析了Voronoi图表达空间数据密集程度的缺陷，并设计了能克服此缺陷的缓冲区生长模型；然后，定义了距离矩阵、岛屿缓冲区标识和增长因子，构建了缓冲区生长模型；最后，通过对模型的动态构建和更新实现了岛屿的自动选取，并选取多组不同海域、不同分布特征的岛屿资料图进行了实验验证。实验结果表明，缓冲区生长模型有效解决了Voronoi图表达岛屿密集程度时的缺陷问题，与使用Voronoi图表达岛屿密集程度的岛屿选取方法相比，明显提高了岛屿选取的质量，且可适用于更多的复杂海域。

A Method for Islands Automatic Selection Based on Buffer Dynamic Growing Model

Nowadays, the existing methods usually utilize the Voronoi diagram for automatically generalizing the islands in chart, but it is hard for them to make the generalized results meet the actual requirement due to the significant reasons that that the Voronoi diagram cannot represent the density and distribution of the islands accurately in chart cartography generalization. Aiming at these drawbacks, a method for islands automatic selection based on buffer dynamic growing model is proposed. Firstly, the drawbacks of Voronoi diagram representing density and distribution of spatial data are analyzed theoretically, and the buffer growing model is designed which can overcome these drawbacks. Secondly, the concepts of distance matrix, island buffer's identification and growth factor are defined, and the buffer growth model is constructed. Then the mechanism for updating the model dynamically is designed. Finally, the islands in chart are automatically selected through building and maintaining the model dynamically, and several groups of islands with different types of sea areas are selected for experimental verification. The experimental results show that:(1) the buffer growth model is effective for representing the density and distribution of the islands; (2) the proposed method improves the quality of the island which is obviously much higher than that of the methods based on Voronoi diagram, and it can be applied into more types of sea areas.