Is vision good enough for language? Recent advancements in multimodal models primarily stem from the powerful reasoning abilities of large language models (LLMs). However, the visual component typically depends only on the instance-level contrastive language-image pre-training (CLIP). Our research reveals that the visual capabilities in recent multimodal LLMs (MLLMs) still exhibit systematic shortcomings. To understand the roots of these errors, we explore the gap between the visual embedding space of CLIP and vision-only self-supervised learning. We identify ''CLIP-blind pairs'' - images that CLIP perceives as similar despite their clear visual differences. With these pairs, we construct the Multimodal Visual Patterns (MMVP) benchmark. MMVP exposes areas where state-of-the-art systems, including GPT-4V, struggle with straightforward questions across nine basic visual patterns, often providing incorrect answers and hallucinated explanations. We further evaluate various CLIP-based vision-and-language models and found a notable correlation between visual patterns that challenge CLIP models and those problematic for multimodal LLMs. As an initial effort to address these issues, we propose a Mixture of Features (MoF) approach, demonstrating that integrating vision self-supervised learning features with MLLMs can significantly enhance their visual grounding capabilities. Together, our research suggests visual representation learning remains an open challenge, and accurate visual grounding is crucial for future successful multimodal systems.

通过对CLIP模型的视觉嵌入空间与仅视觉自监督学习的对比研究，我们发现最新的多模态大型语言模型（MLLMs）在视觉能力方面仍然存在系统性缺陷。为了解决这些问题，我们提出了一种特征混合（MoF）方法，通过将视觉自监督学习特征与MLLMs相结合，显著提高了它们的视觉基础能力，从而表明视觉表示学习仍然是一个待解决的问题，并且准确的视觉基础对于未来成功的多模态系统至关重要。

多模态LLM的视觉缺陷探究