Concept-Guided Prompt Learning for Generalization in Vision-Language Models
Yi Zhang, Ce Zhang, Ke Yu, Yushun Tang, Zhihai He
TL;DR
The paper addresses the limited generalization of CLIP-based fine-tuning on fine-grained and cross-domain tasks. It introduces Concept-Guided Prompt Learning (CPL), which builds a visual concept cache and uses a transformer-based projector to map multi-level visual features into the text space, complemented by a task adapter to preserve pre-trained knowledge while learning task-specific cues. CPL achieves state-of-the-art results across base-to-novel generalization, cross-dataset transfer, and domain generalization, with ablations showing each component materially contributes to performance and efficiency. This approach enables more consistent visual-language alignment by leveraging transferable low-level visual concepts, offering practical improvements for open-vocabulary vision-language tasks. The method is computationally efficient and shows strong generalization across diverse datasets, signaling meaningful impact for real-world VLM deployment.
Abstract
Contrastive Language-Image Pretraining (CLIP) model has exhibited remarkable efficacy in establishing cross-modal connections between texts and images, yielding impressive performance across a broad spectrum of downstream applications through fine-tuning. However, for generalization tasks, the current fine-tuning methods for CLIP, such as CoOp and CoCoOp, demonstrate relatively low performance on some fine-grained datasets. We recognize the underlying reason is that these previous methods only projected global features into the prompt, neglecting the various visual concepts, such as colors, shapes, and sizes, which are naturally transferable across domains and play a crucial role in generalization tasks. To address this issue, in this work, we propose Concept-Guided Prompt Learning (CPL) for vision-language models. Specifically, we leverage the well-learned knowledge of CLIP to create a visual concept cache to enable concept-guided prompting. In order to refine the text features, we further develop a projector that transforms multi-level visual features into text features. We observe that this concept-guided prompt learning approach is able to achieve enhanced consistency between visual and linguistic modalities. Extensive experimental results demonstrate that our CPL method significantly improves generalization capabilities compared to the current state-of-the-art methods.
