gistfile1.rb

class CarrierStringIO < StringIO
  def original_filename
    # the real name does not matter
    "photo.jpeg"
  end

  def content_type
    "image/jpeg"
  end
end

class Account < ActiveRecord::Base
   mount_uploader :logo, LogoUploader
   
   def logo_data=(data)
    io = CarrierStringIO.new(Base64.decode64(data))
    self.logo = io
  end
end

class LogoUploader < CarrierWave::Uploader::Base
  include Cloudinary::CarrierWave

  process :convert => 'png'
  process :tags => ['logo']

  version :standard do
    cloudinary_transformation :transformation => [{:width => 140 , :height => 140, :crop => :limit}]
  end

  version :thumbnail do
    cloudinary_transformation :transformation => [{:width => 70, :height => 70, :crop => :limit}]
  end

end