Discrete Robust Matrix Factorization Hashing for Large-Scale Cross-Media Retrieval

Cross-media hashing, which encodes data points from different modalities into a common Hamming space, has been successfully applied to solve large-scale multimedia retrieval issue due to storage efficiency and search effectiveness. Recently, matrix factorization based hashing methods have drawn considerable attention for their promising search accuracy. However, pioneer methods mainly focus on learning consensus hash codes for different modalities, but neglect the potential inconsistency among different modalities, e.g., the diversities of different modalities and noises, which may undermine the retrieval accuracy. To address this problem, we propose a novel unsupervised hashing model, namely, Discrete Robust Matrix Factorization Hashing (DRMFH), which simultaneously formulates the consistency and inconsistency across different modalities into a matrix factorization based model. Specifically, a homogenous space composed of a consistent Hamming space and an inconsistent diversity part, are generated by matrix factorization for each modality. Therefore, the consensus information across different modalities can be well captured in the learnt hash codes, leading to improved retrieval performance. Moreover, we design an effective optimization algorithm which is able to obtain an approximate discrete code matrix with linear time complexity. Comprehensive experimental results on three public multimedia retrieval datasets show that the proposed DRMFH outperforms several state-of-the-art methods.