reverting to cpu image caching

nerfstudio/data/datamanagers/full_images_datamanager.py

@@ -59,7 +59,7 @@ class FullImageDatamanagerConfig(DataManagerConfig):
     new images. If -1, never pick new images."""
     eval_image_indices: Optional[Tuple[int, ...]] = (0,)
     """Specifies the image indices to use during eval; if None, uses all."""
-    cache_images: Literal["no-cache", "cpu", "gpu"] = "gpu"
+    cache_images: Literal["no-cache", "cpu", "gpu"] = "cpu"
     """Whether to cache images in memory. If "numpy", caches as numpy arrays, if "torch", caches as torch tensors."""