Update app.py

app.py

@@ -35,7 +35,10 @@ def pil_image_to_data_uri(img, format='PNG'):
 def run(image, item_name):
     print("sketch updated")
     print(image)
-    if image["composite"] is None:
+    empty_image = Image.new("L", (512, 512), 255)
+    diff = ImageChops.difference(image, empty_image)
+    # if image["composite"] is None:
+    if not diff.getbbox():
         ones = Image.new("L", (512, 512), 255)
         return ones
     print(item_name.split()[1])