The PHP Exif Library (PEL) lets you fully manipulate Exif (Exchangeable Image File Format) data. This is the data that digital cameras place in their images, such as the date and time, shutter speed, ISO value and so on.
Using PEL, one can fully modify the Exif data, meaning that it can be both read and written. Completely new Exif data can also be added to images. PEL is written completely in PHP and depends on nothing except a standard installation of PHP, version 5.