Install imagemagick with PHP imagick extension on CentOS
To install imagemagick with PHP imagick extension on Linux CentOS you must follow these steps:

[root@server ~]#yum install ImageMagick.i386
[root@server ~]#yum install ImageMagick-devel.i386
[root@server ~]#pecl install imagick

At the end of the installation, create an inclusion file for imagick.so module and restart apache:

[root@server ~]#echo “extension=imagick.so” > /etc/php.d/imagick.ini
[root@server ~]#/etc/init.d/httpd restart

Check the correct loading of the imagick module with:
[root@server ~]# php -m | grep imagick