Megvii-BaseDetection / Megvii-BaseDetection/YOLOX
I have some questions about the calculation of network LOSS
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Description

yolo_head.py get_losses()
I found that the calculation of loss_obj was for all anchor, and I didn't find a method similar to focal loss to suppress the problem of uneven positive and negative samples. Isn't there a problem with that? In addition, loss_obj is simply divided by the number of positive samples(num_fg). Why?
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- Read the whole issue, then the project's contributing guide.
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Research direction
Start in yolo_head.py at get_losses() and trace how loss_obj is computed for anchors, how positive samples are identified, and why num_fg is used for normalization. Compare the implementation with the issue's questions about focal-loss-like handling and positive/negative imbalance. Done means documenting or correcting the behavior with evidence from the relevant loss-calculation code and tests, if available.
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Assessment
- Tech stack
- python, pytorch
- Domain
- machine-learning
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100