photo.rb

class Photo < ActiveRecord::Base
  belongs_to :album

  named_scope :covers, :conditions => {:cover => true}
  has_attached_file :image,
  :storage => :s3,
  :s3_credentials => "#{RAILS_ROOT}/config/amazon_s3.yml",
  :path => ":attachment/:id/:style/:basename.:extension",
  :styles => {
    :original => {:geometry => "500x375>", :processors => [:thumbnail, :watermark], :quality => :better },
    :thumb => {:geometry => "350x270>", :processors => [:thumbnail]}
  }

  validates_attachment_content_type :image,
  :content_type => [ 'image/jpeg',
                     'image/pjpeg', # for progressive jpeg (IE mine-type for regular jpeg) 
                     'image/jpg',
                     'image/x-png', # IE mine-type for PNG
                     'image/png',
                     'image/gif' ]

  validates_attachment_size :image, :less_than => 2.megabytes

end