IPDH: An Improved Pairwise-Based Deep Hashing Method for Large-Scale Image Retrieval

Hashing technique has been extensively utilized in approximate nearest neighbor (ANN) search for large-scale image retrieval by virtue of its storage simplicity and computational efficiency. Recently, many researches show that hashing methods based. on deep neural networks (DNNs) can improve retrieval accuracy by simultaneously learning both deep feature representation and hashing functions in an end-to-end framework. Most deep supervised hashing methods aim to preserve the distance or similarity between data points using the similarity relationships constructed based on semantic labels of images, while ignoring the classification ability of the generated hash codes. However, the semantic labels themselves carry more information than the corresponding similarity labels. We propose an Improved Pairwise-based Deep Hashing (IPDH) method to generate hash codes with powerful classification ability by exploring the global distribution of semantic labels. Specifically, the proposed IPDH method aims to minimize the information loss generated during the process of classification prediction to ensure that the output predicted labels of the network model has a similar distribution with those from the original semantic labels. Comprehensive experiments show that the proposed IPDH method can obtain better improvement than other state-of-the-art algorithms.