To resize an image or photo in Ruby use the following code:

require 'net/http'

param_operation = "width"
param_value = 100 # New width in pixels.

image_url = "http://images.rethumb.com/image_coimbra_600x300.jpg"
image_filename = "resized-image.jpg"

Net::HTTP.start("api.rethumb.com") do |http|
    resp = http.get("/v1/#{param_operation}/#{param_value}/#{image_url}")
    open(image_filename, "wb") do |file|
        file.write(resp.body)
    end
end

Use the following commands to get started:

$ git clone https://github.com/rethumb/rethumb-ruby-examples.git
$ cd rethumb-ruby-examples
$ ruby resize-by-width.rb