[bug] handle missing placeholder images when lisa_on_cuda is installed as dependency

lisa_on_cuda/utils/utils.py

@@ -170,10 +170,15 @@ def dict_to_cuda(input_dict):
 def create_placeholder_variables():
     import cv2
 
-    placeholders_folder = ROOT / "resources" / "placeholders"
-    logging.info(f"placeholders_folder:{placeholders_folder}.")
-    no_seg_out = cv2.imread(str(placeholders_folder / "no_seg_out.png"))[:, :, ::-1]
-    error_happened = cv2.imread(str(placeholders_folder / "error_happened.png"))[:, :, ::-1]
+    try:
+        placeholders_folder = ROOT / "resources" / "placeholders"
+        logging.info(f"placeholders_folder:{placeholders_folder}.")
+        no_seg_out = cv2.imread(str(placeholders_folder / "no_seg_out.png"))[:, :, ::-1]
+        error_happened = cv2.imread(str(placeholders_folder / "error_happened.png"))[:, :, ::-1]
+    except Exception as e:
+        logging.error(f"e:{e}.")
+        logging.error(f"ROOT:{ROOT}.")
+        no_seg_out = error_happened = np.zeros((100, 100, 3))
     return {
         "no_seg_out": no_seg_out,
         "error_happened": error_happened