Installation
Using apt on Debian based systems
sudo apt-get install php5-imagick
Using Homebrew on OSX/macOs
brew install imagemagick
To see the dependencies installed using the brew
method, visit brewformulas.org/Imagemagick.
Using binary releases
Instructions on imagemagick website.
Usage
<?php
$imagen = new Imagick('imagen.jpg');
$imagen->thumbnailImage(100, 0);
//if you put 0 in the parameter aspect ratio is maintained
echo $imagen;
?>