Resume training for cars

[wileewang]

Hi! Thanks for your fantastic work! I ran into some problems when I try to resume training for car using other dataset. It is quite wierd that when I use pre-trained model provided by you to train, the output image for the first iteration looks bad but it works when using inference script. I wonder what mistakes I have made.
I just use the checkpoint_path to feed your pretrained models instead of resume_training_from_ckpt.