CarrierWave rake task to reprocess images for an object

carrierwave.rake

# CarrierWave rake tasks
#
# Task:   reprocess
# Desc:   Reprocess all images for a given class
# Usage:  rake carrierwave:reprocess class=<ClassName> mount_uploader=<mount_uploader>

namespace :carrierwave do
  task :reprocess, [:class, :mount_uploader] => :environment do |task, args|
    desc "Reprocess all images for a given class."
    args[:class].constantize.all.each do |object|
      begin
        object.update_attribute(args[:mount_uploader].to_sym, object.instance_eval(args[:mount_uploader]))
      rescue
        false
      end
    end
  end
end