MixMask: Revisiting Masked Siamese Self-supervised Learning in Asymmetric Distance

Recent advances in self-supervised learning integrate Masked Modeling and Siamese Networks into a single framework to fully reap the advantages of both the two techniques. However, previous erasing-based masking scheme in masked image modeling is not originally designed for siamese networks. Existing approaches simply inherit the default loss design from previous siamese networks, and ignore the information loss and distance change after employing masking operation in the frameworks. In this paper, we propose a filling-based masking strategy called MixMask to prevent information loss due to the randomly erased areas of an image in vanilla masking method. We further introduce a dynamic loss function design with soft distance to adapt the integrated architecture and avoid mismatches between transformed input and objective in Masked Siamese ConvNets (MSCN). The dynamic loss distance is calculated according to the proposed mix-masking scheme. Extensive experiments are conducted on various datasets of CIFAR-100, Tiny-ImageNet and ImageNet-1K. The results demonstrate that the proposed framework can achieve better accuracy on linear probing, semi-supervised and {supervised finetuning}, which outperforms the state-of-the-art MSCN by a significant margin. We also show the superiority on downstream tasks of object detection and segmentation. Our source code is available at https://github.com/LightnessOfBeing/MixMask.