Create an image manipulation web service. The service should be able to proxy images from a source, manipulate them, and return a new image.

image-service.rb

require 'sinatra'
require 'open-uri'
require 'RMagick'
include Magick

get '/' do
  'This service is currently REST only.
  You will have to manually request service by typing and entering your own URI like so:
  <p><tt>acme.com/&lt;image_url&gt;?w=XX&h=XX</tt></p>'
end

get %r{([^?]+)} do

  url = 'http:/' + params[:captures].first
  uri = URI.parse( url )

  # extract extension
  re = /\.(\w{3})$/
  ext = re.match( url )[1]
  if (ext == 'jpg'); ext = 'jpeg'; end

  str = ''
  uri.open {|f| str = f.read }
  img = Image.from_blob( str ).first
  img.resize_to_fill!( params[:w].to_i, params[:h].to_i )

  content_type "image/#{ext}"
  img.to_blob

end