Nearest neighbor search is to find the data points in the database such that the distances from them to the query are the smallest, which is a fundamental problem in various domains, such as computer vision, recommendation systems and machine learning. Hashing is one of the most widely used method for its computational and storage efficiency. With the development of deep learning, deep hashing methods show more advantages than traditional methods. In this paper, we present a comprehensive survey of the deep hashing algorithms. Based on the loss function, we categorize deep supervised hashing methods according to the manners of preserving the similarities into: pairwise similarity preserving, multiwise similarity preserving, implicit similarity preserving, as well as quantization. In addition, we also introduce some other topics such as deep unsupervised hashing and multi-modal deep hashing methods. Meanwhile, we also present some commonly used public datasets and the scheme to measure the performance of deep hashing algorithms. Finally, we discussed some potential research directions in the conclusion.

本文旨在详细研究包括深度监督哈希与深度无监督哈希在内的深度哈希算法，并探讨半监督深哈希、域自适应深哈希和多模态深哈希等相关重要主题，同时介绍公共数据集和深哈希算法性能的评估方法，并提出潜在的研究方向。

深度哈希方法综述