SYN-32 Use the ANTIALIAS resize method for thumbnailing images

synapse/media/v1/thumbnailer.py

@@ -48,7 +48,7 @@ class Thumbnailer(object):
 
     def scale(self, output_path, width, height, output_type):
         """Rescales the image to the given dimensions"""
-        scaled = self.image.resize((width, height), Image.BILINEAR)
+        scaled = self.image.resize((width, height), Image.ANTIALIAS)
         return self.save_image(scaled, output_type, output_path)
 
     def crop(self, output_path, width, height, output_type):
@@ -65,7 +65,7 @@ class Thumbnailer(object):
         if width * self.height > height * self.width:
             scaled_height = (width * self.height) // self.width
             scaled_image = self.image.resize(
-                (width, scaled_height), Image.BILINEAR
+                (width, scaled_height), Image.ANTIALIAS
             )
             crop_top = (scaled_height - height) // 2
             crop_bottom = height + crop_top
@@ -73,7 +73,7 @@ class Thumbnailer(object):
         else:
             scaled_width = (height * self.width) // self.height
             scaled_image = self.image.resize(
-                (scaled_width, height), Image.BILINEAR
+                (scaled_width, height), Image.ANTIALIAS
             )
             crop_left = (scaled_width - width) // 2
             crop_right = width + crop_left