fix: close Image.open with context manager and clean up ValueError message in YOLO loader

Author: satishkc7

src/supervision/dataset/formats/yolo.py

@@ -228,14 +228,15 @@ def load_yolo_annotations(
                 continue
 
             # PIL is much faster than cv2 for checking image shape and mode: https://github.com/roboflow/supervision/issues/1554
-            image = Image.open(image_path)
+            with Image.open(image_path) as image:
+                w, h = image.size
+                mode = image.mode
             lines = read_txt_file(file_path=annotation_path, skip_empty=True)
-            w, h = image.size
             resolution_wh = (w, h)
-            if image.mode not in ("RGB", "L"):
+            if mode not in ("RGB", "L"):
                 raise ValueError(
-                    f"Images must be 'RGB' or 'grayscale', \
-                but {image_path} mode is '{image.mode}'."
+                    f"Images must be 'RGB' or 'grayscale',"
+                    f" but {image_path} mode is '{mode}'."
                 )
 
             with_masks = force_masks or _with_seg_mask(lines=lines)

tests/dataset/test_show_progress.py

@@ -166,12 +166,12 @@ def test_load_coco_show_progress(coco_dataset: dict, show_progress: bool) -> Non
 
 
 def test_load_coco_show_progress_consistent(coco_dataset: dict) -> None:
-    classes_off, paths_off, ann_off = load_coco_annotations(
+    classes_off, paths_off, _ann_off = load_coco_annotations(
         images_directory_path=coco_dataset["images_dir"],
         annotations_path=coco_dataset["annotations_path"],
         show_progress=False,
     )
-    classes_on, paths_on, ann_on = load_coco_annotations(
+    classes_on, paths_on, _ann_on = load_coco_annotations(
         images_directory_path=coco_dataset["images_dir"],
         annotations_path=coco_dataset["annotations_path"],
         show_progress=True,