In this survey, we propose to explore and discuss the common rules behind knowledge transfer works for vision recognition tasks. To achieve this, we firstly discuss the different kinds of reusable knowledge existing in a vision recognition task, and then we categorize different knowledge transfer approaches depending on where the knowledge comes from and where the knowledge goes. Compared to previous surveys on knowledge transfer that are from the problem-oriented perspective or from the technique-oriented perspective, our viewpoint is closer to the nature of knowledge transfer and reveals common rules behind different transfer learning settings and applications. Besides different knowledge transfer categories, we also show some research works that study the transferability between different vision recognition tasks. We further give a discussion about the introduced research works and show some potential research directions in this field.

中文翻译：

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视觉识别中的知识转移

在本次调查中，我们建议探索和讨论视觉识别任务的知识转移工作背后的共同规则。为此，我们首先讨论视觉识别任务中存在的不同类型的可重用知识，然后根据知识的来源和去向对不同的知识转移方法进行分类。与之前从面向问题的角度或从面向技术的角度对知识迁移的调查相比，我们的观点更接近知识迁移的本质，并揭示了不同迁移学习设置和应用背后的共同规则。除了不同的知识迁移类别外，我们还展示了一些研究不同视觉识别任务之间可迁移性的研究工作。