Depending on what you are looking for you might not need to install anything. There is a command line interface to "Image Events". It is named "sips" (of course... what else?), and it is self documenting with the command "sips --help".
Oh.. and there is always "perl -MCPAN -e". It is a simple way of installing a lot of perl modules. remember to use it as root (or sudo'ed).