Pyramid transformer-based triplet hashing for robust visual place recognition

Abstract

Deep hashing is being used to approximate nearest neighbor search for large-scale image recognition problems. However, CNN architectures have dominated similar applications. We present a Pyramid Transformer-based Triplet Hashing architecture to handle large-scale place recognition challenges in this study, leveraging the capabilities of Vision Transformer (ViT). For feature representation, we create a Siamese Pyramid Transformer backbone. We present a multi-scale feature aggregation technique to learn discriminative features for scale-invariant features. In addition, we observe that binary codes suitable for place recognition are sub-optimal. To overcome this issue, we use a self-restraint triplet loss deep learning network to create compact hash codes, further increasing recognition accuracy. To the best of our knowledge, this is the first study to use a triplet loss deep learning network to handle the deep hashing learning problem. We do extensive experiments on four difficult place datasets: KITTI, Nordland, VPRICE, and EuRoC. The experimental findings reveal that the suggested technique performs at the cutting edge of large-scale visual place recognition challenges.