Local Photon - For Dynamic Image Resizing

What does it do?

This repo piggybacks on WordPress' open-source Photon project letting you dynamically resize and manipulate images via a URL.

How does it work?

We map requests to jpg, jpeg, png, and gif URLs to run through a PHP script that uses Photon to resize and manipulate the images. If the images don't exist locally then they can be mapped to an external URL.

Example:

http://example.dev/img/picture.jpg?w=250 will resize an image to 250 pixels wide. If http://example.dev/img/picture.jpg doesn't exist the script can automatically fallback to making a request to an external domain like http://example.com/img/picture.jpg to use for resizing and manipulation.

How do I install it?

Copy image-proxy.php to the root of your site. Add the contents of local-photon.nginx.conf to your nginx servers configuration which will map requests to image through the image-proxy.php script. The proxy script expects a copy of the Photon project one level above the root directory of your site. You can checkout the latest version of Photon like so:

sudo svn co http://code.svn.wordpress.org/photon/

Photon also requires the GraphicsMagick library See install-graphicsmagick.sh for details

How can I configure this script?

In image-proxy.php you can change the location of where the Photon project is located. You can also add a config.php file with filters to change various aspects of Photon.

To specify an external domain to proxy requests that are missing locally add the following to config.php:

add_filter( 'external_fallback_domain', function() {
  return 'https://external-domain.com';
} );