Retrain Tensorflow Object detection API

Question

I have read tutorials on how to train a new class using TensorFlow Object Detection API. But what I want to do is to add a new class to the already trained classes of a pre-trained model.

For example : MS-COCO pre-trained model has 90 classes. I want to add one more class and detect objects for 91 classes.

Answer 1

Tensorflow object detection API supports starting from a pre-trained MS COCO checkpoint. Just set

fine_tune_checkpoint: "/usr/home/username/tmp/model.ckpt-#####"
from_detection_checkpoint: true

In your detection pipeline. (Official reference: https://github.com/tensorflow/models/blob/master/research/object_detection/g3doc/configuring_jobs.md)

You should add the images with your extra class to the coco dataset and finetune for all 91 classes, or your network might forget what it learned previously and only detect the new object.