Bump quality value on resized JPEGs

src/wagtail_bynder/models.py

@@ -340,19 +340,29 @@ def convert_downloaded_image(
         format, mime-type and file size of the newly generated image without
         having to perform any more file operations.
         """
-        original_width, original_height = self.width, self.height
-
-        # Filter.run() expects the object's width and height to reflect
-        # the image we're formatting, so we update them temporarily
-        self.width, self.height = utils.get_image_dimensions(source_file)
+        original_format, width, height, is_animated = (
+            utils.get_image_format_and_dimensions(source_file)
+        )
 
         # Retreieve maximum height and width from settings
         max_width = int(getattr(settings, "BYNDER_IMAGE_MAX_WIDTH", 3500))
         max_height = int(getattr(settings, "BYNDER_IMAGE_MAX_HEIGHT", 3500))
 
+        filter_str = f"max-{max_width}x{max_height}"
+        output_format = utils.get_output_image_format(
+            original_format, is_animated=is_animated
+        )
+        if output_format == "jpeg":
+            # Since this will be a source image, use a higher JPEG quality than normal
+            filter_str += " jpegquality-90"
+
+        # Filter.run() expects the object's width and height to reflect
+        # the image we're formatting, so we update them temporarily
+        original_width, original_height = self.width, self.height
+        self.width, self.height = width, height
         try:
             # Use wagtail built-ins to resize/reformat the image
-            willow_image = Filter(f"max-{max_width}x{max_height}").run(
+            willow_image = Filter(filter_str).run(
                 self,
                 target_file,
                 source_file,

src/wagtail_bynder/utils.py

@@ -61,9 +61,31 @@ def download_image(url: str) -> InMemoryUploadedFile:
     return download_file(url, max_filesize, max_filesize_setting_name)
 
 
-def get_image_dimensions(file: File) -> tuple[int, int]:
+def get_image_format_and_dimensions(file: File) -> tuple[str, int, int, bool]:
     willow_image = Image.open(file)
-    return willow_image.get_size()
+
+    return (
+        (willow_image.format_name,)
+        + willow_image.get_size()
+        + (willow_image.has_animation())
+    )
+
+
+def get_output_image_format(original_format: str, *, is_animated: bool = False):
+    conversions = {
+        "avif": "png",
+        "bmp": "png",
+        "webp": "png",
+    }
+    if is_animated:
+        # Convert non-animated GIFs to PNG as well
+        conversions["gif"] = "png"
+
+    # Allow the user to override the conversions
+    custom_conversions = getattr(settings, "WAGTAILIMAGES_FORMAT_CONVERSIONS", {})
+    conversions.update(custom_conversions)
+
+    return conversions.get(original_format, original_format)
 
 
 def filename_from_url(url: str) -> str: