Rewrite image processing engine pretty majorly

1 files changed, 38 insertions, 0 deletions

diff --git a/lib/booru/image_processing/jpeg_processor.rb b/lib/booru/image_processing/jpeg_processor.rb
new file mode 100644
index 0000000..2fab4da
--- /dev/null
+++ b/lib/booru/image_processing/jpeg_processor.rb
@@ -0,0 +1,38 @@
+require 'shellwords'
+
+module Booru
+  module ImageProcessing
+    class JpegProcessor < Processor
+      include ShellHelper
+
+      def pre_process
+        # Perform lossy rotation on image if it has EXIF orientation field
+        # (web browsers do not respect that, see http://caniuse.com/#search=image-orientation)
+        image = ::MiniMagick::Image.open(@original_path)
+        orientation = image.exif['Orientation']
+        if orientation.to_i > 1 # 1 is the default orientation
+          image.auto_orient
+          image.strip # remove EXIF metadata to prevent image from being rotated again
+          image.write(@original_path)
+        end
+      end
+
+      def generate_version(dimensions, destination_path)
+        width, height = dimensions
+
+        # resize JPEG to desired size and jpegtran the resized version.
+        ::MiniMagick::Tool::Convert.new do |cmd|
+          cmd.resize "#{width}x#{height}"
+          cmd << @original_path
+          cmd << destination_path
+        end
+
+        jpegtran(destination_path)
+      end
+
+      def post_process
+        jpegtran(@original_path)
+      end
+    end
+  end
+end
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