gistfile1.txt

    # This will produce two derivative datastreams 'avatar_medium' and 'avatar_thumb'. The original will be just 'avatar'
    #   has_file_datastream 'avatar', :styles => { :medium => "300x300>", :thumb => "100x100>" }, :default_url => "/images/:style/missing.png"
    #
    # This will call a processor Transcoding::Ocr and store the text in 'document_text'
    #   has_file_datastream 'document', :styles => { :text => { :quality => :better } },
    #                      :processors => [:ocr]
    #
    # process_in_background :avatar, queue: 'avatar'
    # process_in_background :document, queue: 'extract_text'