Detectron2 model zoo's experimental settings and a few implementation details are different from Detectron.
The differences in implementation details are shared in Compatibility with Other Libraries.
The differences in model zoo's experimental settings include:
- Use scale augmentation during training. This improves AP with lower training cost.
 - Use L1 loss instead of smooth L1 loss for simplicity. This sometimes improves box AP but may affect other AP.
 - Use 
POOLER_SAMPLING_RATIO=0instead of 2. This does not significantly affect AP. - Use 
ROIAlignV2. This does not significantly affect AP. 
In this directory, we provide a few configs that do not have the above changes. They mimic Detectron's behavior as close as possible, and provide a fair comparison of accuracy and speed against Detectron.
| Name | lr sched  | 
train time (s/iter)  | 
inference time (s/im)  | 
train mem (GB)  | 
box AP  | 
mask AP  | 
kp. AP  | 
model id | download | 
|---|---|---|---|---|---|---|---|---|---|
| Faster R-CNN | 1x | 0.219 | 0.038 | 3.1 | 36.9 | 137781054 | model | metrics | ||
| Keypoint R-CNN | 1x | 0.313 | 0.071 | 5.0 | 53.1 | 64.2 | 137781195 | model | metrics | |
| Mask R-CNN | 1x | 0.273 | 0.043 | 3.4 | 37.8 | 34.9 | 137781281 | model | metrics | 
Comparisons:
- Faster R-CNN: Detectron's AP is 36.7, similar to ours.
 - Keypoint R-CNN: Detectron's AP is box 53.6, keypoint 64.2. Fixing a Detectron's bug lead to a drop in box AP, and can be compensated back by some parameter tuning.
 - Mask R-CNN: Detectron's AP is box 37.7, mask 33.9. We're 1 AP better in mask AP, due to more correct implementation.
 
For speed comparison, see benchmarks.