diff --git a/src/lerobot/datasets/compute_stats.py b/src/lerobot/datasets/compute_stats.py
index 6316dbee3..4b55750a6 100644
--- a/src/lerobot/datasets/compute_stats.py
+++ b/src/lerobot/datasets/compute_stats.py
@@ -242,7 +242,7 @@ def sample_images(image_paths: list[str]) -> np.ndarray:
     images = None
     for i, idx in enumerate(sampled_indices):
         path = image_paths[idx]
-        # we load as uint8 to reduce memory usage
+        # we load RGB images as uint8 to reduce memory usage
         img = load_image_as_numpy(path, dtype=np.uint8, channel_first=True)
         img = auto_downsample_height_width(img)
 
diff --git a/src/lerobot/scripts/lerobot_dataset_viz.py b/src/lerobot/scripts/lerobot_dataset_viz.py
index a5f3ba11b..21ae1ac9d 100644
--- a/src/lerobot/scripts/lerobot_dataset_viz.py
+++ b/src/lerobot/scripts/lerobot_dataset_viz.py
@@ -157,7 +157,7 @@ def visualize_dataset(
         stats = dataset.meta.stats[key]
         lo = stats["q01"] if "q01" in stats else stats["min"]
         hi = stats["q99"] if "q99" in stats else stats["max"]
-        depth_ranges[key] = (float(lo), float(hi))
+        depth_ranges[key] = (float(np.asarray(lo).item()), float(np.asarray(hi).item()))
 
     first_index = None
     for batch in tqdm.tqdm(dataloader, total=len(dataloader)):