Please look through these requirements before attempting to install Gallery!
Apache is the preferred web server for a Gallery installation. It's free, open source and available from the Apache project's website. Apache runs on many different operating systems, including BSD, Linux, and Windows.
Gallery is written in PHP, a language specifically crafted for web-based applications. PHP is available freely from http://www.php.net. PHP can be installed under Apache or IIS; installation procedures are available through PHP's documentation
In addition to just a PHP installation, Gallery requires certain PHP directives or settings to be set a certain way. In most cases, Gallery will run under default settings, but if you host has changed some directives, it can affect the way Gallery runs.
To check the status of your PHP settings, navigate to http://www.example.com/gallery/setup/phpinfo.php, where http://www.example.com/gallery is where you have uncompressed Gallery. Search for the following directives and make sure they are set appropriately.
safe_mode - Safe mode must be disabled
disable_functions - exec() must not be listed in PHP's disable_functions directive
file_uploads - File uploads must be enabled (set to 'On')
If any of those conditions are not met, Gallery will not work on your host
Gallery requires you to install NetPBM or ImageMagick in order for it to perform basic image operations (resize, rotate, crop, etc...). It is possible that your host already has one of these two libraries installed (only one or the other is needed). If not, you can download pre-compiled binaries for use on various systems from our download page. Just download the appropriate binaries that correspond to the architecure and operating system of your server and upload them to a folder in binary mode (if using FTP).
Gallery has the ability to use several outside libraries and programs in order to enhance functionality, though these programs aren't required for a basic working Gallery
mod_rewrite is an Apache module (not available on IIS installations) that allows Gallery to use shorter URLs for your albums. For instance, using mod_rewrite, a URL referring to an album might appear like http://www.example.com/gallery/trip_to_spain, instead of a longer http://www.example.com/gallery/view_album.php?set_albumName=trip_to_spain
mod_rewrite requires administrator access to install (if not previously enabled) and modification to the AllowOverride directive in httpd.conf. More information is in the Apache documentation
jhead is a free tool that can be used to extract EXIF data from images, which most digital cameras now add to photos. If enabled, EXIF data will be available for viewing by clicking on the [properties] link by individual images.
More information can be found at the jhead website
zipinfo is a free tool that allows Gallery to unzip ZIP archives so that you can easily upload multiple photos. If enabled, you will be able to upload a ZIP archive as you would any other single picture, and Gallery will add all the images in the archive.
zipinfo can be obtained from the Info-ZIP website
jpegtran is a free tool that allows Gallery to loselessly rotate JPEG images. While NetPBM and ImageMagick can rotate JPEG images, jpegtran allows you to rotate images without risking degradation.
More information can be found at the Independent JPEG Group's website