Data augmentation has become a standard component of vision pre-trained models to capture the invariance between augmented views. In practice, augmentation techniques that mask regions of a sample with zero/mean values or patches from other samples are commonly employed in pre-trained models with self-/semi-/fully-supervised contrastive losses. However, the underlying mechanism behind the effectiveness of these augmentation techniques remains poorly explored. To investigate the problems, we conduct an empirical study to quantify how data augmentation affects performance. Concretely, we apply 4 types of data augmentations termed with Random Erasing, CutOut, CutMix and MixUp to a series of self-/semi-/fully- supervised pre-trained models. We report their performance on vision tasks such as image classification, object detection, instance segmentation, and semantic segmentation. We then explicitly evaluate the invariance and diversity of the feature embedding. We observe that: 1) Masking regions of the images decreases the invariance of the learned feature embedding while providing a more considerable diversity. 2) Manual annotations do not change the invariance or diversity of the learned feature embedding. 3) The MixUp approach improves the diversity significantly, with only a marginal decrease in terms of the invariance.

数据增强已成为视觉预训练模型的标准组成部分，用于捕捉增强视图之间的不变性。本研究通过实证研究来量化数据增强对性能的影响，发现图像的区域遮盖减少了学到的特征嵌入的不变性，同时提供了更多的多样性。手动注释不会改变学到的特征嵌入的不变性或多样性。MixUp方法在多样性方面得到了显著改善，对不变性只有轻微的降低。

探索数据扩增在自监督/半监督/全监督预训练模型上的应用