NeuroHash: A Hyperdimensional Neuro-Symbolic Framework for Spatially-Aware Image Hashing and Retrieval
Sanggeon Yun, Ryozo Masukawa, SungHeon Jeong, Mohsen Imani
TL;DR
NeuroHash tackles spatially-aware image retrieval in large datasets by integrating pre-trained vision backbones with a Hyperdimensional Computing (HDC) framework to encode spatial structure into high-dimensional vectors. It introduces a self-supervised context-aware HDC encoder, a spatial encoding scheme using positional hypervectors, and a trainable multilinear hyperplane hashing to map high-dimensional representations to compact binary hashes. The system supports conditional retrieval by reweighting global and local symbols, enabling focus on specific objects or regions. Experiments on CIFAR-10 and MS COCO demonstrate competitive mean average precision at 5K ($\mathrm{mAP@5K}$) and a spatial-aware metric $\mathrm{mAP@5K_r}$, with ablations confirming the contribution of all components. The approach offers a flexible neuro-symbolic framework with transparency and potential extensions to temporal information and other modalities.
Abstract
Customizable image retrieval from large datasets remains a critical challenge, particularly when preserving spatial relationships within images. Traditional hashing methods, primarily based on deep learning, often fail to capture spatial information adequately and lack transparency. In this paper, we introduce NeuroHash, a novel neuro-symbolic framework leveraging Hyperdimensional Computing (HDC) to enable highly customizable, spatially-aware image retrieval. NeuroHash combines pre-trained deep neural network models with HDC-based symbolic models, allowing for flexible manipulation of hash values to support conditional image retrieval. Our method includes a self-supervised context-aware HDC encoder and novel loss terms for optimizing lower-dimensional bipolar hashing using multilinear hyperplanes. We evaluate NeuroHash on two benchmark datasets, demonstrating superior performance compared to state-of-the-art hashing methods, as measured by mAP@5K scores and our newly introduced metric, mAP@5Kr, which assesses spatial alignment. The results highlight NeuroHash's ability to achieve competitive performance while offering significant advantages in flexibility and customization, paving the way for more advanced and versatile image retrieval systems.
