In current cPanel version, you may install Image Magick easily by running the script as below:
/scripts/installimagemagick
if the installation not completed this way , You may use the manual way from cPanel script to get it complete.
/scripts/installrpm ImageMagick /scripts/installrpm ImageMagick-devel wget layer1.cpanel.net/magick.tar.gz tar zxvf magick.tar.gz cd magick sh install
Done.