text: Title: faster-rcnn performance
  Body: hi, wuyuxin
  Thank you for sharing this wonderful project! Here I have some performance problems of faster-rcnn.
  
  In coco dataset, experiments results show GN has better performance. 
  R50-FPN | 38.9;35.4
  R50-FPN-GN | 40.4;36.3
  
  However, in my dataset(ocr icdar2017), GN performance is poor than FreezeBN. Scratch performance is also poor than pre-trainend which is contrary to your conclusion. Here are the results on my dataset.
  pre-train, resnet101, FreezeBN,  freeze_AT=2, f-score:0.7742
  pre-train, resnet101, GN,  freeze_AT=2, f-score:0.7605
  no pre-train(From Scratch), resnet101, GN,  freeze_AT=0, f-score:0.7106
  
  Hope for your suggestion.
  
  
  