ExifReader用于读取JPEG文件中的Exif信息。 Exif包括了拍摄照片时的众多信息，例如曝光时间、焦距、快门速度等等。-ExifReader used to read the Exif information in the JPEG files. When Exif includes photos of many information, such as exposure time, focal length, the shutter speed, and so on.