Dual Graph Network Hashing for Cross-Modal Retrieval
Hashing algorithms represent data by generating compact binary hash codes, enabling efficient cross-modal similarity search and significantly improving the storage efficiency and retrieval performance of image-text data. However, because traditional hashing methods typically separate image-text feature extraction from hash learning, the feature extraction module struggles to adaptively update based on training feedback, further limiting the performance of cross-modal retrieval in real-world scenarios. To address this issue, deep learning has been introduced to cross-modal hashing, enabling end-to-end joint optimization and tightly integrating feature extraction and hash learning, significantly improving retrieval performance. However, because existing deep learning methods often use a fixed weight distribution when processing samples, they ignore the modal differences between text and visual features when fusing them. This leads to an inadequate fused representation and difficulty achieving optimal modality alignment during hash code generation. To address this issue, we propose a Dual Graph Network Hashing (DGNH) algorithm that dynamically adjusts the weight distribution between visual and text features through an adaptive attention mechanism, ensuring better modality fusion during hash code generation. Specifically, we design a novel framework that combines a graph convolutional neural network (GCN) with a graph attention network (GAT) to construct a label classifier for generating labels and enhancing cross-modal feature representation. This approach improves feature discrimination by capturing the hierarchical relationships and co-occurrence patterns of labels through a carefully constructed label association graph. Furthermore, we introduced a pre-trained model combining CLIP and the Transformer to further enhance the overall feature representation. During the optimization phase, we employed a contrastive triplet loss function coupled with novel regularization constraints for quantization and optimization, thus effectively reducing information loss during discretization and ensuring the generated hash codes are more compact and efficient. Experimental results on three public datasets, MS-COCO, NUS-WIDE, and MIRFlickr-25 K, demonstrate that the proposed method outperforms existing methods in both retrieval accuracy and efficiency, thereby validating its effectiveness and superiority.