Installing/Configuring
PHP Manual

Requirements

Your PHP must be compiled in with --enable-exif. To enable multibyte support in EXIF tags, the mbstring extension must be enabled by compiling PHP with --enable-mbstring. PHP does not require any additional library for the exif module.

Windows only: The mbstring extension must always be enabled. Note that mbstring extension must be loaded prior to EXIF in php.ini.


Installing/Configuring
PHP Manual