Update app.py

app.py

@@ -12,11 +12,11 @@ from PIL import Image
 # -- install pre-build detectron2
 os.system('pip install git+https://github.com/facebookresearch/detectron2.git')
 os.system('pip install pyyaml==5.1')
-os.system('pip install opencv-python')
 
 import detectron2
 
 from detectron2.utils.logger import setup_logger # ????
+from google.colab.patches import cv2_imshow
 
 from detectron2 import model_zoo
 from detectron2.engine import DefaultPredictor