Title
Relieving Long-tailed Instance Segmentation via Pairwise Class Balance
Abstract
Long-tailed instance segmentation is a challenging task due to the extreme imbalance of training samples among classes. It causes severe biases of the head classes (with majority samples) against the tailed ones. This renders “how to appropriately define and alleviate the bias” one of the most important issues. Prior works mainly use label distribution or mean score information to indicate a coarse-grained bias. In this paper, we explore to excavate the confusion matrix, which carries the fine-grained misclassification details, to relieve the pairwise biases, generalizing the coarse one. To this end, we propose a novel Pairwise Class Balance (PCB) method, built upon a confusion matrix which is updated during training to accumulate the ongoing prediction preferences. PCB generates fightback soft labels for regularization during training. Besides, an iterative learning paradigm is developed to support a progressive and smooth regularization in such debiasing. PCB can be plugged and played to any existing method as a complement. Experimental results on LVIS demonstrate that our method achieves state-of-the-art performance without bells and whistles. Superior results across various architectures show the generalization ability. The code and trained models are available at https://github.com/megvii-research/PCB.
Year
DOI
Venue
2022
10.1109/CVPR52688.2022.00687
IEEE Conference on Computer Vision and Pattern Recognition
Keywords
DocType
Volume
Transfer/low-shot/long-tail learning, Recognition: detection,categorization,retrieval
Conference
2022
Issue
Citations 
PageRank 
1
0
0.34
References 
Authors
0
5
Name
Order
Citations
PageRank
Yin-Yin He100.34
Peizhen Zhang200.68
Xiu-Shen Wei300.34
Xiangyu Zhang413044437.66
Jian Sun525842956.90