Linguistic-Aware Patch Slimming Framework for Fine-grained Cross-Modal Alignment

Cross-modal alignment aims to build a bridge connecting vision and language. It is an important multi-modal task that efficiently learns the semantic similarities between images and texts. Traditional fine-grained alignment methods heavily rely on pre-trained object detectors to extract region features for subsequent region-word alignment thereby incurring substantial computational costs for region detection and error propagation issues for two-stage training. In this paper we focus on the mainstream vision transformer incorporating patch features for patch-word alignment while addressing the resultant issue of visual patch redundancy and patch ambiguity for semantic alignment. We propose a novel Linguistic-Aware Patch Slimming (LAPS) framework for fine-grained alignment which explicitly identifies redundant visual patches with language supervision and rectifies their semantic and spatial information to facilitate more effective and consistent patch-word alignment. Extensive experiments on various evaluation benchmarks and model backbones show LAPS outperforms the state-of-the-art fine-grained alignment methods by 5%-15% rSum. Our code is available at https://github.com/CrossmodalGroup/LAPS