原文有提到：
There is a currently a limit of 97825 tiles per map
eg: 200×100 map has 20000 tiles（例：200x100的地图为20000个图块）
就是说地图最多97825个图块，超出无效
另：
This script provides two functions:
Screenshot – take a picture of the current screen
Mapshot – take a picture of the map
The default key for taking a screenshot is F6.
The default key for taking a mapshot is F7.
意思是截图有两种方法，F6为当前屏幕所显示的地图的截取，F7为整个地图的截取。
截图分别保存在根目录的Screenshots（屏幕截图），与Mapshots（地图的截图）里面。
调用脚本截取地图的方法为：
ms = Map_Saver.new(map_id)
bmp = ms.map_image
