Carrierwave upload with darken filter

README.md

Carrierwave upload with darken filter

Simple demo of a Carrierwave uploader that uses MiniMagick to darken the uploaded images.

photo_uploader.rb

class PhotoUploader < CarrierWave::Uploader::Base
  include CarrierWave::MiniMagick

  storage :file

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end


  def extension_white_list
    %w(jpg jpeg gif png)
  end

  version :dark do
    process darken: 0.5
  end
  
  def darken(ratio)
    manipulate! do |image|
      image.fill 'black'
      image.colorize "#{100 * ratio}%"
      image = yield image if block_given?
      image
    end
  end
end