Merge pull request thumbor#578 from Jimdo/clean_up_jpeg_config

clean up PILLOW_JPEG-options

thumbor/config.py

@@ -32,14 +32,15 @@
 Config.define('ALLOWED_SOURCES', [], "Allowed domains for the http loader to download. These are regular expressions.", 'Imaging')
 Config.define('QUALITY', 80, 'Quality index used for generated JPEG images', 'Imaging')
 Config.define('PROGRESSIVE_JPEG', True, 'Exports JPEG images with the `progressive` flag set.', 'Imaging')
+
 Config.define('PILLOW_JPEG_SUBSAMPLING', None,
-              'Specify subsampling behavior for Pillow (see `subsampling` in '
-              'http://pillow.readthedocs.org/en/latest/handbook/image-file-formats.html#jpeg).', 'Imaging')
-Config.define(
-    'PILLOW_COPY_JPEG_SETTINGS',
-    False,
-    'If True, use qtables and subsampling from orginal JPG file. Useful if you want to keep jpg quality as identical as '
-    'possible to original file. Will ignore QUALITY and PILLOW_JPEG_SUBSAMPLING.', 'Imaging')
+    'Specify subsampling behavior for Pillow (see `subsampling` in http://pillow.readthedocs.org/en/latest/handbook/image-file-formats.html#jpeg). '
+    'Be careful to use int for 0,1,2 and string for "4:4:4" notation. '
+    'Will ignore `quality`. Using `keep` will copy the original file\'s subsampling.', 'Imaging')
+Config.define('PILLOW_JPEG_QTABLES', None,
+    'Specify quantization tables for Pillow (see `qtables` in http://pillow.readthedocs.org/en/latest/handbook/image-file-formats.html#jpeg). '
+    'Will ignore `quality`. Using `keep` will copy the original file\'s qtables.', 'Imaging')
+
 Config.define('WEBP_QUALITY', None, 'Quality index used for generated WebP images. If not set (None) the same level of '
               'JPEG quality will be used.', 'Imaging')
 Config.define('AUTO_WEBP', False, 'Specifies whether WebP format should be used automatically if the request accepts it '

thumbor/engines/pil.py

@@ -136,17 +136,23 @@ def read(self, extension=None, quality=None):  # NOQA
                 self.image = self.image.convert('RGB')
             else:
 
-                quantization = self.qtables
-                subsampling = self.subsampling
-                copy_jpg_settings = self.context.config.PILLOW_COPY_JPEG_SETTINGS
+                subsampling_config = self.context.config.PILLOW_JPEG_SUBSAMPLING
+                qtables_config = self.context.config.PILLOW_JPEG_QTABLES
 
-                if copy_jpg_settings and (subsampling is not None) and quantization and 2 <= len(quantization) <= 4:
+                if subsampling_config is not None or qtables_config is not None:
                     options['quality'] = 0  # can't use 'keep' here as Pillow would try to extract qtables/subsampling and fail
-                    options['qtables'] = quantization
-                    options['subsampling'] = subsampling
+                    orig_subsampling = self.subsampling
+                    orig_qtables = self.qtables
 
-            if self.context.config.PILLOW_JPEG_SUBSAMPLING:
-                options['subsampling'] = int(self.context.config.PILLOW_JPEG_SUBSAMPLING)
+                    if (subsampling_config == 'keep' or subsampling_config is None) and (orig_subsampling is not None):
+                        options['subsampling'] = orig_subsampling
+                    else:
+                        options['subsampling'] = subsampling_config
+
+                    if (qtables_config == 'keep' or qtables_config is None) and (orig_qtables and 2 <= len(orig_qtables) <= 4):
+                        options['qtables'] = orig_qtables
+                    else:
+                        options['qtables'] = qtables_config
 
         if options['quality'] is None:
             options['quality'] = self.context.config.QUALITY

vows/pil_engine_vows.py

@@ -16,6 +16,7 @@
 ctx = Vows.Context
 
 import thumbor.engines.pil as PIL
+
 from os.path import join, abspath, dirname
 
 FIXTURES_FOLDER = join(abspath(dirname(__file__)), 'fixtures')
@@ -68,13 +69,14 @@ def should_store_subsampling_in_engine(self, engine):
         def should_store_quantization_in_engine(self, engine):
             expect(len(engine.qtables)).to_equal(2)
 
-    class WritingJpegImage(ctx):
+    class WritingJpegImageWithOriginalJpegSettings(ctx):
         def topic(self):
             config = Config()
             server = ServerParameters(
                 8889, 'localhost', 'thumbor.conf', None, 'info', None
             )
-            config.PILLOW_COPY_JPEG_SETTINGS = True
+            config.PILLOW_JPEG_SUBSAMPLING = 'keep'
+            config.PILLOW_JPEG_QTABLES = 'keep'
             context = Context(server, config, Importer(config))
 
             with open("%s/quantization.jpg" % FIXTURES_FOLDER, "rb") as f:
@@ -86,12 +88,37 @@ def topic(self):
 
             return engine.image
 
-        def should_save_with_stored_subsampling_if_quality_is_None(self, image):
+        def should_save_with_stored_subsampling(self, image):
             expect(image.encoderinfo.get('subsampling')).to_equal(0)
 
-        def should_save_with_stored_qtables_if_quality_is_None(self, image):
+        def should_save_with_stored_qtables(self, image):
             expect(len(image.encoderinfo.get('qtables'))).to_equal(2)
 
+    class WritingJpegImageWithExplicitJpegSettings(ctx):
+        def topic(self):
+            config = Config()
+            server = ServerParameters(
+                8889, 'localhost', 'thumbor.conf', None, 'info', None
+            )
+            config.PILLOW_JPEG_SUBSAMPLING = 2
+            config.PILLOW_JPEG_QTABLES = 'web_high'
+            context = Context(server, config, Importer(config))
+
+            with open("%s/quantization.jpg" % FIXTURES_FOLDER, "rb") as f:
+                buffer = f.read()
+
+            engine = PIL.Engine(context=context)
+            engine.load(buffer, '.jpg')
+            engine.read('.jpg', None)
+
+            return engine.image
+
+        def should_save_with_explicit_subsampling(self, image):
+            expect(image.encoderinfo.get('subsampling')).to_equal(2)
+
+        def should_save_with_explicit_qtables(self, image):
+            expect(image.encoderinfo.get('qtables')).to_equal('web_high')
+
     class ResizedPaletteImage(ctx):
         def topic(self):
             engine = PIL.Engine(None)