1 files changed, 24 insertions, 0 deletions
diff --git a/lib/paperclip/lazy_thumbnail.rb b/lib/paperclip/lazy_thumbnail.rb
new file mode 100644
index 000000000..42f9a557a
--- /dev/null
+++ b/lib/paperclip/lazy_thumbnail.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Paperclip
+  class LazyThumbnail < Paperclip::Thumbnail
+    def make
+      return File.open(@file.path) unless needs_convert?
+      Paperclip::Thumbnail.make(file, options, attachment)
+    end
+
+    private
+
+    def needs_convert?
+      needs_different_geometry? || needs_different_format?
+    end
+
+    def needs_different_geometry?
+      !@target_geometry.nil? && @current_geometry.width != @target_geometry.width && @current_geometry.height != @target_geometry.height
+    end
+
+    def needs_different_format?
+      @format.present? && @current_format != @format
+    end
+  end
+end