Automatic Image Resizing for Jekyll

This gem allows you to easily use MiniMagick to resize your images and automatically includes an @2x version for use with retina.js. This is a forked version of jekyll-minimagick modified specifically to add the generation of @2x versions of all of the image sizes. This is very much still a work in progress. If you would like to help out, make a fork and then submit a pull request.

Basic Setup

Requirements

You have to have imagemagick install on your machine. If you are using a mac and use homebrew, you can install imagemagick by runing brew install imagemagick.

Installation

Install the gem:

[sudo] gem install jekyll-retinamagick

In a plugin file within your Jekyll project's _plugins directory:

# _plugins/my-plugin.rb
require "jekyll-retinamagick"

Define presets in your _config.yml file, like this:

# _config.yml
retinamagick:
    thumbnail:
        source: img/photos/original
        destination: img/photos/thumbnail
        resize: "100x100"
    medium:
        source: img/photos/original
        destination: img/photos/medium
        resize: "600x400"

This configuration will create a 100x100 thumbnail for each image in img/photos/original and put it in _site/img/photos/thumbnail. It will also generate a 200x200 thumbnail and add an @2x between the file name and the extention. It will also generate a 600x400 and 1200x800 image in a similar way and then place them in _site/img/photos/medium.

Bundler Setup

Already using bundler to manage gems for your Jekyll project? Then just add

gem "jekyll-retinamagick"

to your gemfile and create the following plugin in your projects _plugins directory. I've called mine bundler.rb.

# _plugins/bundler.rb
require "rubygems"
require "bundler/setup"
require "jekyll-imagemagick"