Can I add new training pictures to my object detection model without re-running the whole training again?
I used yolov5 to train an object detection model. is it possible to add more annotated images after i have already trained the original model or must i restart the whole training with the new set of images?

You are asking about continual learning - this is a very active field of research, and there is no single solution/method to tackle it. You'll have to do more research to find the right approach for your specific settings.
