To install ImageMagick in a cPanel server:
root@server [~]#
/scripts/installimagemagickImageMagick installed ok
root@server [~]# which convert
/usr/bin/convert
root@server [~]# /usr/bin/convert --version
Version: ImageMagick 6.7.8-8 2012-12-17 Q16
http://www.imagemagick.orgCopyright: Copyright (C) 1999-2012 ImageMagick Studio LLC