diff --git a/src/diffusers/image_processor.py b/src/diffusers/image_processor.py
index 9893f7163853..843052c1adf3 100644
--- a/src/diffusers/image_processor.py
+++ b/src/diffusers/image_processor.py
@@ -33,14 +33,7 @@
     List[torch.FloatTensor],
 ]
 
-PipelineDepthInput = Union[
-    PIL.Image.Image,
-    np.ndarray,
-    torch.FloatTensor,
-    List[PIL.Image.Image],
-    List[np.ndarray],
-    List[torch.FloatTensor],
-]
+PipelineDepthInput = PipelineImageInput
 
 
 class VaeImageProcessor(ConfigMixin):
@@ -169,7 +162,7 @@ def convert_to_grayscale(image: PIL.Image.Image) -> PIL.Image.Image:
     @staticmethod
     def blur(image: PIL.Image.Image, blur_factor: int = 4) -> PIL.Image.Image:
         """
-        Blurs an image.
+        Applies Gaussian blur to an image.
         """
         image = image.filter(ImageFilter.GaussianBlur(blur_factor))
 
@@ -402,6 +395,7 @@ def binarize(self, image: PIL.Image.Image) -> PIL.Image.Image:
         """
         image[image < 0.5] = 0
         image[image >= 0.5] = 1
+
         return image
 
     def get_default_height_width(