Revert "Merge pull request AlchemyCMS#1878 from tvdeyen/preprocess-im…

…ages"

This reverts commit 3072ac9, reversing
changes made to 1e7c025.

app/models/alchemy/picture.rb

@@ -56,25 +56,12 @@ class Picture < BaseRecord
       raise PictureInUseError, Alchemy.t(:cannot_delete_picture_notice) % { name: name }
     end
 
-    # Image preprocessing class
-    def self.preprocessor_class
-      @_preprocessor_class ||= Preprocessor
-    end
-
-    # Set a image preprocessing class
-    #
-    #     # config/initializers/alchemy.rb
-    #     Alchemy::Picture.preprocessor_class = My::ImagePreprocessor
-    #
-    def self.preprocessor_class=(klass)
-      @_preprocessor_class = klass
-    end
-
     # Enables Dragonfly image processing
     dragonfly_accessor :image_file, app: :alchemy_pictures do
       # Preprocess after uploading the picture
-      after_assign do |image|
-        self.class.preprocessor_class.new(image).call
+      after_assign do |p|
+        resize = Config.get(:preprocess_image_resize)
+        p.thumb!(resize) if resize.present?
       end
     end