If you are interested in testing and trying object recognition with TensorFlow, I recommend this Medium post:
Building a Real-Time Object Recognition App with Tensorflow and OpenCV.
I tried it and it works quite well and the available source code allows you to learn how this all works.
You should also read Dat Tran follow up post, that shows how to train the NN with your own images, to identify new objects.
How to train your own Object Detector with TensorFlow’s Object Detector API