Exif是一种图像文件格式，它的数据存储与JPEG格式是完全相同的。实际上Exif格式就是在JPEG格式头部插入了数码照片的信息，包括拍摄时的光圈、快门、白平衡、ISO、焦距、日期时间等(Exif is an image file format whose data storage is exactly the same as in the JPEG format. In fact, the Exif format is in the JPEG format, the head inserted