说明：  用IDL实现遥感图像处理中使用矢量文件进行遥感影像裁剪，主要步骤为：获取矢量文件地理坐标，转为ROI，确定裁减区域，进行裁剪。
(IDL achieve vector files used in remote sensing image processing for remote sensing image cropping, major steps: get the geographic coordinates of the vector file, converted to ROI, determine the clipping region, and crop.)