Adaptive resampling method for images (Fix #174)

When loading an image for thumbnails and previews, the resampling method is now determined by the size of the original image. Now low resolution images use "nearest neighbor" sampling while higher resolution images continue to use "bilinear" sampling.
TagStudioDev · May 19, 2024 · 699ecd3 · 699ecd3
1 parent 9d7609a
commit 699ecd3
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/tagstudio/src/qt/widgets/thumb_renderer.py b/tagstudio/src/qt/widgets/thumb_renderer.py
@@ -107,7 +107,7 @@ def render(
         adj_size = math.ceil(max(base_size[0], base_size[1]) * pixel_ratio)
         if is_loading:
             final = ThumbRenderer.thumb_loading_512.resize(
-                (adj_size, adj_size), resample=resampling_method
+                (adj_size, adj_size), resample=Image.Resampling.BILINEAR
             )
             qim = ImageQt.ImageQt(final)
             pixmap = QPixmap.fromImage(qim)
@@ -163,7 +163,7 @@ def render(
                 # No Rendered Thumbnail ========================================
                 else:
                     image = ThumbRenderer.thumb_file_default_512.resize(
-                        (adj_size, adj_size), resample=resampling_method
+                        (adj_size, adj_size), resample=Image.Resampling.BILINEAR
                     )
 
                 if not image:
@@ -181,6 +181,14 @@ def render(
 
                 if update_on_ratio_change:
                     self.updated_ratio.emit(new_x / new_y)
+
+                resampling_method = (
+                    Image.Resampling.NEAREST
+                    if max(image.size[0], image.size[1])
+                    < max(base_size[0], base_size[1])
+                    else Image.Resampling.BILINEAR
+                )
+
                 image = image.resize((new_x, new_y), resample=resampling_method)
                 if gradient:
                     mask: Image.Image = ThumbRenderer.thumb_mask_512.resize(