PHP exif ½éÉÜ

 // PHP exif
// --
//¡¡wikipedia ½éÉÜ£º
//¡¡EXIF£¨Exchangeable image file format£©Êǿɽ»»»Í¼ÏñÎļþµÄËõд£¬ÊÇרÃÅΪÊýÂëÏà»úµÄÕÕƬÉ趨µÄ£¬¿ÉÒԼǼÊýÂëÕÕƬµÄÊôÐÔÐÅÏ¢ºÍÅÄÉãÊý¾Ý¡£
//¡¡EXIF¿ÉÒÔ¸½¼ÓÓÚJPEG¡¢TIFF¡¢RIFFµÈÎļþÖ®ÖУ¬ÎªÆäÔö¼ÓÓйØÊýÂëÏà»úÅÄÉãÐÅÏ¢µÄÄÚÈݺÍË÷Òýͼ»òͼÏñ´¦ÀíÈí¼þµÄ°æ±¾ÐÅÏ¢¡£
// --
// php ÖÐ exif ¿ÉÒÔ´¦ÀíͼƬµÄÔªÊý¾Ý¡£ÀýÈ磺¿ÉÒÔ¶ÁÈ¡ÊýÂëÏà»úÕÕµ½µÄÕÕƬµÄÔªÊý¾Ý¡£
// With the exif extension you are able to work with image meta data.
// For example, you may use exif functions to read meta data of pictures taken from digital cameras
// by working with information stored in the headers of the JPEG and TIFF images.
//
// Windows Óû§Ê¹ÓøÃÀ©Õ¹±ØÐëÆôÓà mbstring À©Õ¹£¬²¢ÇÒ mbstring À©Õ¹±ØÐëÔÚ exif ֮ǰ¼ÓÔÚ¡£
// Windows users must enable both the php_mbstring.dll and php_exif.dll DLL's in php.ini.
// The php_mbstring.dll DLL must be loaded before the php_exif.dll DLL so adjust your php.ini accordingly.
// --
//
// º¯Êý
exif_imagetype()
// 1/1
// »ñȡͼƬµÄÀ©Õ¹£¬·µ»ØÒ»¸öÕûÊý£¬¶ÔÓ¦ÓÚ exif Öеij£Á¿
exif_read_data()
// 1/4
// Reads the EXIF headers from JPEG or TIFF, ·µ»ØÒ»Êý×é
// EXIF headers tend to be present in JPEG/TIFF images generated by digital cameras,
// but unfortunately each digital camera maker has a different idea of how to actually tag their images,
// so you can't always rely on a specific Exif header being present.
exif_tagname()
// 1/1
exif_thumbnail()
// 1/4
// Retrieve the embedded thumbnail of a TIFF or JPEG image
read_exif_data()
// alias of exif_read_data()