Visual Perturbation and Adaptive Hard Negative Contrastive Learning for Compositional Reasoning in Vision-Language Models
Journal:
arXiv
Published Date:
May 21, 2025
Abstract
Vision-Language Models (VLMs) are essential for multimodal tasks, especially
compositional reasoning (CR) tasks, which require distinguishing fine-grained
semantic differences between visual and textual embeddings. However, existing
methods primarily fine-tune the model by generating text-based hard negative
samples, neglecting the importance of image-based negative samples, which
results in insufficient training of the visual encoder and ultimately impacts
the overall performance of the model. Moreover, negative samples are typically
treated uniformly, without considering their difficulty levels, and the
alignment of positive samples is insufficient, which leads to challenges in
aligning difficult sample pairs. To address these issues, we propose Adaptive
Hard Negative Perturbation Learning (AHNPL). AHNPL translates text-based hard
negatives into the visual domain to generate semantically disturbed image-based
negatives for training the model, thereby enhancing its overall performance.
AHNPL also introduces a contrastive learning approach using a multimodal hard
negative loss to improve the model's discrimination of hard negatives within
each modality and a dynamic margin loss that adjusts the contrastive margin
according to sample difficulty to enhance the distinction of challenging sample
pairs. Experiments on three public datasets demonstrate that our method
effectively boosts VLMs' performance on complex CR tasks. The source code is
available at https://github.com/nynu-BDAI/AHNPL.