A novel cross-modal hashing algorithm based on multimodal deep learning

With the growing popularity of multimodal data on the Web, cross-modal retrieval on large-scale multimedia databases has become an important research topic. Cross-modal retrieval methods based on hashing assume that there is a latent space shared by multimodal features. To model the relationship among heterogeneous data, most existing methods embed the data into a joint abstraction space by linear projections. However, these approaches are sensitive to noise in the data and are unable to make use of unlabeled data and multi-modal data with missing values in real-world applications. To address these challenges, we proposed a novel multimodal deep-learning-based hash (MDLH) algorithm. In particular, MDLH uses a deep neural network to encode heterogeneous features into a compact common representation and learns the hash functions based on the common representation. The parameters of the whole model are fine-tuned in a supervised training stage. Experiments on two standard datasets show that the method achieves more effective results than other methods in cross-modal retrieval.创新点随着网络上多模态数据的普及, 海量多媒体数据库上的跨模态检索成为研究的热点。跨模态检索方法假设多个模态的数据特征之间存在一个共享的潜在特征空间。因此, 为了建立多模态数据之间的关联, 大部分已有方法通过线性映射将多模态数据分别映射到同一个共享特征空间。但是, 该类方法对于数据中的噪声比较敏感, 并且也无法使用现实场景中的无标记的数据或缺失模态的数据。针对该问题本文提出了一种新的基于多模态深度学习的哈希算法。该方法使用深度神经网络结构将异构特征映射为一个共同的压缩表示, 并在此表示的基础上学习哈希函数。整个模型的参数通过有监督的方式进行训练。在两个标准数据集上的实验结果显示本文的方法能够有效的完成跨模态检索的任务。