对称房屋

In topographic map, especially for city area, most of features are central symmetry and axial symmetry. By means of extracting features with symmetric figure first and then vectoring them according to their geometric characteristic, accuracy and efficiency can be increased and data sizes can be reduced.

在地形图中，轴对称和中心对称的要素占据着相当大的比例，特别是城市地形图中，房屋建筑等具有对称形状的要素占据了地形图中要素的绝大部分，在扫描图中首先对这些要素进行提取，进而根据特定要素的几何特征矢量化，可显著地提高矢量化精度和效率，减少数据的储存量。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。