How to install ImageMagick PHP module on Ubuntu and Debian

ImageMagick is a very popular image editing suite, and for good reasons. It's command-based and is very capable; making it perfect as a backend to many other image manipulation tools.

The default image library for PHP is GD. You can use ImageMagick to replace GD in PHP by installing php-imagick PHP module for Ubuntu and Debian.

1. Open terminal from the application launcher or via the <ctrl> + <alt> + <t> keyboard shortcut.
2. Update apt's package list.

   $ sudo apt update
   [sudo] password for user:
   Hit:1 http://jp.archive.ubuntu.com/ubuntu disco InRelease
   Hit:2 http://jp.archive.ubuntu.com/ubuntu disco-updates InRelease
   Hit:3 http://jp.archive.ubuntu.com/ubuntu disco-backports InRelease
   Hit:4 http://jp.archive.ubuntu.com/ubuntu disco-security InRelease
   Reading package lists... Done
   Building dependency tree
   Reading state information... Done
   3 packages can be upgraded. Run 'apt list --upgradable' to see them.

3. Install php-imagick package via apt.

   $ sudo apt install --assume-yes php-imagick
   Reading package lists... Done
   Building dependency tree
   Reading state information... Done
   The following additional packages will be installed:
     fontconfig-config fonts-dejavu-core fonts-droid-fallback fonts-noto-mono ghostscript gsfonts
     imagemagick-6-common libavahi-client3 libavahi-common-data libavahi-common3 libcups2
     libcupsfilters1 libcupsimage2 libfftw3-double3 libfontconfig1 libgomp1 libgs9 libgs9-common
     libijs-0.35 libjbig0 libjbig2dec0 libjpeg-turbo8 libjpeg8 liblcms2-2 liblqr-1-0 libltdl7
     libmagickcore-6.q16-6 libmagickwand-6.q16-6 libpaper-utils libpaper1 libtiff5 libwebp6
     php-common php7.2-cli php7.2-common php7.2-json php7.2-opcache php7.2-phpdbg php7.2-readline
     poppler-data ttf-dejavu-core
   Suggested packages:
     fonts-noto ghostscript-x cups-common libfftw3-bin libfftw3-dev liblcms2-utils
     libmagickcore-6.q16-6-extra php-pear poppler-utils fonts-japanese-mincho | fonts-ipafont-mincho
     fonts-japanese-gothic | fonts-ipafont-gothic fonts-arphic-ukai fonts-arphic-uming fonts-nanum
   The following NEW packages will be installed:
     fontconfig-config fonts-dejavu-core fonts-droid-fallback fonts-noto-mono ghostscript gsfonts
     imagemagick-6-common libavahi-client3 libavahi-common-data libavahi-common3 libcups2
     libcupsfilters1 libcupsimage2 libfftw3-double3 libfontconfig1 libgomp1 libgs9 libgs9-common
     libijs-0.35 libjbig0 libjbig2dec0 libjpeg-turbo8 libjpeg8 liblcms2-2 liblqr-1-0 libltdl7
     libmagickcore-6.q16-6 libmagickwand-6.q16-6 libpaper-utils libpaper1 libtiff5 libwebp6
     php-common php-imagick php7.2-cli php7.2-common php7.2-json php7.2-opcache php7.2-phpdbg
     php7.2-readline poppler-data ttf-dejavu-core
   0 upgraded, 42 newly installed, 0 to remove and 2 not upgraded.
   Need to get 23.3 MB of archives.
   ##### snipped

4. Check if imagick module is loaded by PHP to confirm installation was successful.

   $ php --modules | grep imagick
   imagick

5. Restart Apache or any other services dependent on PHP.

   $ sudo systemctl restart apache2