How do I label images faster
On the internet, LabelImg is pretty popular. It's a Python program that you can use to automatize drawing of bounding boxes. Alternatively there is HyperLabel, on their website they say it's free so it.s worth to give it a try.

The options available are so many I completely get lost while searching. I suggest you to read this nice review of tools first.

With these tools, labeling 1600 images is not going to be a problem IMHO. Good luck.