My Ubuntu doesn't have ImageMagick. I tried to install it from terminal as the instruction in answer. But it gives me error when I input command sudo apt-get install imagemagick php5-imagick. The error is
xinru@xinru-Alienware-13-R2:~$ sudo apt-get install imagemagick php5-imagick
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package php5-imagick is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'php5-imagick' has no installation candidate
Anyone can help me with this problem, please. Thank you!