Multi-Modal Adapter for Vision-Language Models
Dominykas Seputis, Serghei Mihailov, Soham Chatterjee, Zehao Xiao
TL;DR
This work addresses adapting large vision-language models like CLIP to downstream tasks with limited data. It introduces the Multi-Modal Adapter, a parameter-efficient module that jointly fuses text and image features through a Masked Multi-Head Attention block, aided by dimension downsampling and a fixed blending factor of $\lambda=0.2$ to combine adapted and original embeddings. Across eleven datasets in a 16-shot setting, MMA delivers competitive performance and better generalization to unseen classes, with ablations highlighting the importance of text adaptation. The approach offers a practical path for cross-modal, task-specific adaptation and provides code to facilitate reuse.
Abstract
Large pre-trained vision-language models, such as CLIP, have demonstrated state-of-the-art performance across a wide range of image classification tasks, without requiring retraining. Few-shot CLIP is competitive with existing specialized architectures that were trained on the downstream tasks. Recent research demonstrates that the performance of CLIP can be further improved using lightweight adaptation approaches. However, previous methods adapt different modalities of the CLIP model individually, ignoring the interactions and relationships between visual and textual representations. In this work, we propose Multi-Modal Adapter, an approach for Multi-Modal adaptation of CLIP. Specifically, we add a trainable Multi-Head Attention layer that combines text and image features to produce an additive adaptation of both. Multi-Modal Adapter demonstrates improved generalizability, based on its performance on unseen classes compared to existing adaptation methods. We perform additional ablations and investigations to validate and interpret the proposed approach.
