In this paper, we consider the problem of fine-grained image retrieval in an incremental setting, when new categories are added over time. On the one hand, repeatedly training the representation on the extended dataset is time-consuming. On the other hand, fine-tuning the learned representation only with the new classes leads to catastrophic forgetting. To this end, we propose an incremental learning method to mitigate retrieval performance degradation caused by the forgetting issue. Without accessing any samples of the original classes, the classifier of the original network provides soft "labels" to transfer knowledge to train the adaptive network, so as to preserve the previous capability for classification. More importantly, a regularization function based on Maximum Mean Discrepancy is devised to minimize the discrepancy of new classes features from the original network and the adaptive network, respectively. Extensive experiments on two datasets show that our method effectively mitigates the catastrophic forgetting on the original classes while achieving high performance on the new classes.

本研究针对细粒度图像检索在增量学习场景中的问题，提出一种基于增量学习和最大均值差异的方法，以减轻遗忘问题导致的检索性能降级。通过将原网络的分类器提供的软“标签”传输到训练自适应网络的过程中，达到保留原分类能力的目的，并通过模型正则化来最小化原网络与自适应网络之间的新类特征的偏差。实验结果表明，该方法在保持原类分类性能的同时，对新类有较高的性能表现。

关于细粒度图像检索的增量学习探究