Update app.py

app.py

@@ -34,9 +34,11 @@ def adjust_to_multiple_of_32(width: int, height: int):
 @spaces.GPU(duration=120)
 def process_images(image, prompt="a girl", strength=0.75, seed=0, inference_step=4, progress=gr.Progress(track_tqdm=True)):
     progress(0, desc="Starting")
+
+    if image is None or not hasattr(image, 'size'):
+        raise gr.Error("Please upload an image.")
+
     def process_img2img(image, prompt="a person", strength=0.75, seed=0, num_inference_steps=4):
-        if image is None:
-            return None
         generator = torch.Generator(device).manual_seed(seed)
         width, height = convert_to_fit_size(image.size)
         width, height = adjust_to_multiple_of_32(width, height)