Deep learning approaches are nowadays ubiquitously used to tackle computer vision tasks such as semantic segmentation, requiring large datasets and substantial computational power. Continual learning for semantic segmentation (CSS) is an emerging trend that consists in updating an old model by sequentially adding new classes. However, continual learning methods are usually prone to catastrophic forgetting. This issue is further aggravated in CSS where, at each step, old classes from previous iterations are collapsed into the background. In this paper, we propose Local POD, a multi-scale pooling distillation scheme that preserves long- and short-range spatial relationships at feature level. Furthermore, we design an entropy-based pseudo-labelling of the background w.r.t. classes predicted by the old model to deal with background shift and avoid catastrophic forgetting of the old classes. Finally, we introduce a novel rehearsal method that is particularly suited for segmentation. Our approach, called PLOP, significantly outperforms state-of-the-art methods in existing CSS scenarios, as well as in newly proposed challenging benchmarks.

本文提出了一种名为PLOP的方法，使用了多尺度池化蒸馏技术，在特征级别上保留了长程和短程空间关系，并设计了一种基于熵的伪标签方法来处理背景变化和避免旧类的灾难性遗忘，并引入了一种新的排练方法，特别适用于分割。在现有的连续语境场景以及新的提出的具有挑战性的基准测试中，我们的方法显着优于现有的最先进方法。

解决连续语义分割中的灾难性遗忘和背景偏移