CSS Sprites is a Ruby gem that finds all PNG files in the input directory, merges them together into a single PNG file and generates a CSS stylesheet for the output image.

ImageMagick Version 6.4.9 or later. You can get ImageMagick from www.imagemagick.org.

Or, if you're on Mac OS X and using Homebrew, you can install it by typing:

$ brew install imagemagick

And if you're using Ubuntu:

$ sudo apt-get install libmagickwand-dev

Add this line to your application's Gemfile:

gem 'css_sprites'

And then execute:

$ bundle install

Or install it yourself:

$ gem install css_sprites

In your Ruby app:

require 'css_sprites'
CSSSprites.generate_sprite(path_to_images, options_hash)

Or from the command line:

$ css_sprites path/to/images

In your Ruby app:

options = {
    stacking: :vertical,
    name: 'so_awesome',
    output: 'my_awesome_icons_output'
}
CSSSprites.generate_sprite('my_awesome_icons', options)

From the command line:

$ css_sprites --stacking vertical --name so_awesome --output my_awesome_icons_output my_awesome_icons

For more details:

$ css_sprites --help