DualFocus: A Unified Framework for Integrating Positive and Negative Descriptors in Text-based Person Retrieval

Text-based person retrieval (TPR) aims to retrieve images of a person from an extensive array of candidates based on a given textual description. The core challenge lies in mapping visual and textual data into a unified latent space. While existing TPR methods concentrate on recognizing explicit and positive characteristics, they often neglect the critical influence of negative descriptors, resulting in potential false positives that fulfill positive criteria but could be excluded by negative descriptors. To alleviate these issues, we introduce DualFocus, a unified framework for integrating positive and negative descriptors to enhance the interpretative accuracy of vision-language foundational models regarding textual queries. DualFocus employs Dual (Positive/Negative) Attribute Prompt Learning (DAPL), which integrates Dual Image-Attribute Contrastive (DIAC) Learning and Sensitive Image-Attributes Matching (SIAM) Learning. This way DualFocus enhances the detection of unseen attributes, thereby boosting retrieval precision. To further achieve a balance between coarse and fine-grained alignment of visual and textual embeddings, we propose the Dynamic Tokenwise Similarity (DTS) loss, which refines the representation of both matching and non-matching descriptions, thereby enhancing the matching process through a detailed and adaptable similarity assessment. By focusing on token-level comparisons, DualFocus significantly outperforms existing techniques in both precision and robustness. The experiment results highlight DualFocus's superior performance on CUHK-PEDES, ICFG-PEDES, and RSTPReid.