Image processor latent (#8513)

* fix

* up

---------

Co-authored-by: yiyixuxu <yixu310@gmail,com>

Author: yiyixuxu

src/diffusers/image_processor.py

@@ -569,7 +569,7 @@ def preprocess(
 
             channel = image.shape[1]
             # don't need any preprocess if the image is latents
-            if channel == 4:
+            if channel == self.vae_latent_channels:
                 return image
 
             height, width = self.get_default_height_width(image, height, width)
@@ -585,7 +585,6 @@ def preprocess(
                 FutureWarning,
             )
             do_normalize = False
-
         if do_normalize:
             image = self.normalize(image)