Introduction
Vision-LLMs (VLMs) have made notable advances, enabling machines to process and interpret complex visual and textual data. However, these multimodal systems often face limitations, notably the suboptimal performance of their visual components and the challenge of handling lengthy visual tokens. In this context, a novel approach is proposed utilizing ensemble experts to create poly-visual-expert VLMs. This method takes advantage of the specialized skills of various visual encoders to enrich the VLMs' visual understanding.
Architecture and Methodology
The comprehensive paper begins by evaluating six pre-trained visual experts—CLIP, DINOv2, LayoutLMv3, Convnext, SAM, and MAE—each with distinct capabilities ranging from image-text matching to object segmentation. Subsequently, an integration technique is devised, leveraging multi-expert fusion networks to merge the individual strengths of these encoders effectively. The researchers focus on two key fusion methods, MLP projection and Q-Former, investigating the potential benefits of each for multi-channel signal transmission.
To further refine model efficiency, the problem of excessive vision token generation is addressed with innovative strategies, such as the multi-patch-one-token projection that compresses visual information, and the exploration of varied positional encoding schemes that offer a significant reduction in the positional embeddings required for visual tokens—an important innovation given the inherent position limitations within VLMs.
Experimental Results
The empirical results underscore the effectiveness of the poly-visual-expert approach. As the number of integrated experts increases, the VLMs displayed improved multimodal capabilities across multiple benchmarks. The findings indicate that VLMs with multiple experts outperform those with isolated visual encoders and achieve a significant performance boost, verified through an extensive set of benchmarks.
Contributions and Conclusion
The paper’s contributions include the novel integration of diverse visual encoders into a cohesive model that better handles multimodal tasks, the introduction of efficient methods for encoding visual information, and the empirical validation of the model's superiority compared to existing models with single visual coding channels.
The evolutionary design and merging strategies take inspiration from biological visual systems, thus bringing VLMs a step closer to the complex and nuanced human-like understanding of multimodal information. The researchers believe that the potential of poly-visual-expert VLMs remains untapped, and with further data enhancement, these models can exhibit even greater performance, thereby consolidating the poly-visual-expert design as a promising direction in the development of advanced VLMs.