Prerequisites : There are no strict prerequisites for installing and using the CImg Library. Anyway, we recommend you install one of the binary release of the ImageMagick package on your system. It is the easiest way (although not the only one) to help CImg loading/saving compressed image formats, such as JPEG, PNG, GIF, etc...
You have different ways to get the CImg library :

The CImg library is provided as .zip or .tar.gz packages which are plateform-independent. They contain all the needed library files, as well as various examples illustrating the use of the library functions and classes.

A .deb package file is available for Debian-based Unix distributions (including the well known Ubuntu distro). Copy/Paste the lines below for a quick installation of the latest version of the CImg library under such systems (superuser privileges required) :

wget http://cimg.sourceforge.net/cimg-dev.deb dpkg -i cimg-dev.deb

Pre-compiled binaries of the main library demo file are available for Windows, Linux and MacOSX. Download this archive if you want a quick overview of what the CImg Library can do.
Note that this archive does not contain any sources ! If you want to be able to compile your own programs, download the standard package instead.

You may be also more adventurous and use CVS. This ensures you will get the latest code available, and will ease the updates as well (knowing the tool 'cvs' is needed indeed). To do this, just type the commands :

export CVS_RSH=ssh cvs -d:pserver:anonymous@cimg.cvs.sourceforge.net:/cvsroot/cimg co CImg

in your favorite console. Nevertheless, you have to know that some code in the CVS version may be experimental, so always test the latest stable archive before complaining !