Start by removing any old versions previously installed via apt-get:
sudo apt-get remove imagemagick
Then update apt-get and install some supporting packages:
sudo apt-get update sudo apt-get install libperl-dev gcc libjpeg62-dev libbz2-dev libtiff4-dev libwmf-dev libz-dev libpng12-dev libx11-dev libxt-dev libxext-dev libxml2-dev libfreetype6-dev liblcms1-dev libexif-dev perl libjasper-dev libltdl3-dev graphviz gs-gpl pkg-config
Use wget to grab the source from ImageMagick.org.
Once the source is downloaded, uncompress it:
cdtar xvfz ImageMagick.tar.gz
Now configure and make:
cd ImageMagick-6.5.0-0 ./configure sudo make sudo make install
To avoid an error such as:
convert: error while loading shared libraries: libMagickCore.so.2: cannot open shared object file: No such file or directory
Add the following line to ~/.bashrc:
export LD_LIBRARY_PATH=/usr/local/lib sudo ldconfig
You can confirm the install and available formats with:
identify -list format
Source: http://www.digitalsanctum.com/2009/03/18/installing-imagemagick-from-source-on-ubuntu-804/