Installing an image processing library is an essential part to install Gallery. We've tried to simplify the process quite a bit to aid in making the install painless.
Gallery 1 supports two processing libraries: NetPBM and ImageMagick. The Gallery Support Team recommends using NetPBM if you do not have administrator access on the machine, as we supply pre-compiled binaries for you to upload easily.
Gallery 2 supports four image toolkits: NetPBM, ImageMagick, GD and GraphicsMagick. They're all equally good, though some say that NetPBM has slightly better quality and that ImageMagick is slightly faster than NetPBM. GraphicsMagick and ImageMagick are very similar. GD can be very fast, but it will also use a lot of memory so it may cause you to run into predefined server limits. It is also compiled into PHP by default if your PHP is 4.3.0 or more recent, however it may not have support for all image types (e.g. it might not have JPEG support) and GD is also more error-prone than the other toolkits. If the binaries for NetPBM and ImageMagick are installed in default, or standard, locations then Gallery 2 will auto-detect them during Gallery 2 installation. It won't cause any harm to enable all of these toolkits—in fact you’ll get the widest file type support if you do so.
Note that the Gallery 2 modules called NetPBM and ImageMagick are not the toolkits, but the modules that enables Gallery 2 to use them. Do not enter the path to the gallery2/modules/netpbm or gallery2/modules/imagemagick in the toolkit setup in Gallery 2. Instead, point the modules where the actual binary files are located.
Windows 2003 / IIS 6: See NetPBM for Windows 2003
Also, most Linux distributions offer ImageMagick via their respective package management interfaces.
Note that you will most likely need administrator access to the computer to be able to install ImageMagick. If you don't have that kind of access, you can either ask your host to install it for you or switch to using our precompiled NetPBM binaries instead.
Easy-to-install MacOS X packages can be found at www.entropy.ch
GD is only supported by Gallery 2 & 3. Gallery 2 & 3 detects GD automatically. In site admin -> modules -> image toolkits GD, you can either activate it or not. If you can't activate it, then either your GD version is too old or more probably, GD is not loaded in your PHP. If your Gallery 2 is running on a webserver on a Windows platform and GD is not loaded, you have to uncomment a line in php.ini to load the GD extension:
Change ;extension=php_gd2.dll to extension=php_gd2.dll
GraphicsMagick is only supported by Gallery 2. Gallery 2's imagemagick module works with binaries from either ImageMagick or GraphicsMagick.
Similar to ImageMagick, you can download either precompiled binaries or the source from GraphicsMagick Download Page.