$ easy_install -ZU pgmagick
or
$ pip install --upgrade pgmagick
pgmagick is available on UNIX-like systems. and depend on the following libraries.
$ apt-get install libgraphicsmagick++1-dev
$ apt-get install libboost-python1.40-dev
$ yum install GraphicsMagick-c++-devel
$ yum install boost-devel
$ apt-get install libboost-python-dev
$ apt-get install libgraphicsmagick++1-dev
$ ./configure --enable-shared=yes
$ make && make install