Update app.py

app.py

@@ -151,6 +151,8 @@ def infer(use_custom_model, model_name, weight_name, custom_lora_weight, image_i
     if preprocessor == "lineart": 
         image = load_image(image_in)
         image = np.array(image)
+        image = image[:, :, None]
+        image = np.concatenate([image, image, image], axis=2)
         image = Image.fromarray(image)
     
     if use_custom_model: