A supervised learning to index model for approximate nearest neighbor image retrieval

Abstract Image indexing plays a significant role in approximate K -nearest neighbor image retrieval. In the past decades, the most commonly used methods in image indexing are unsupervised-based. We recognize that unsupervised-based methods cannot benefit from supervised information. In this paper, supervised learning to index method is proposed to realize approximate K -nearest neighbor image retrieval. For designing the supervised learning to index algorithm, we first need to establish the supervision information of an image that should be quantified to the codeword in the codebook. Thus, we propose an image relabeling algorithm to relabel the database images so that the supervised codebook learning can be realized. Second, compared with only distance-based unsupervised image indexing method, a better idea of supervised learning to index is incorporating the distance-based similarities with the classification probabilities of samples at the image indexing stage. In order to achieve this goal, a classifier is also trained based on the relabeled images, and we finally build a constraint optimization objective function to learn the codebook and the classifier simultaneously. The proposed method is verified on the MNIST, the CIFAR-10, and the ImageNet data sets. Experimental results demonstrate the effectiveness of the proposed method.