Chaoxiang Cai

Yibo Jiang, Tao Wu, Rui Jiang et al.

Unified Multimodal Models (UMMs) aim to integrate visual understanding and generation within a single structure. However, these models exhibit a notable capability mismatch, where their understanding capability significantly outperforms their generation. This mismatch indicates that the model's rich internal knowledge, while effective for understanding tasks, remains underactivated during generation. To address this, we draw inspiration from the human ``Thinking-While-Drawing'' paradigm, where humans continuously reflect to activate their knowledge and rectify intermediate results. In this paper, we propose UniRect-CoT, a training-free unified rectification chain-of-thought framework. Our approach unlocks the ``free lunch'' hidden in the UMM's powerful inherent understanding to continuously reflect, activating its internal knowledge and rectifying intermediate results during generation.We regard the diffusion denoising process in UMMs as an intrinsic visual reasoning process and align the intermediate results with the target instruction understood by the model, serving as a self-supervisory signal to rectify UMM generation.Extensive experiments demonstrate that UniRect-CoT can be easily integrated into existing UMMs, significantly enhancing generation quality across diverse complex tasks.

Longrong Yang, Dong Shen, Chaoxiang Cai et al.

The Mixture-of-Experts (MoE) has gained increasing attention in studying Large Vision-Language Models (LVLMs). It uses a sparse model to replace the dense model, achieving comparable performance while activating fewer parameters during inference, thus significantly reducing the inference cost. Existing MoE methods in LVLM encourage different experts to specialize in different tokens, and they usually employ a router to predict the routing of each token. However, the router is not optimized concerning distinct parameter optimization directions generated from tokens within an expert. This may lead to severe interference between tokens within an expert. To address this problem, we propose to use the token-level gradient analysis to Solving Token Gradient Conflict (STGC) in this paper. Specifically, we first use token-level gradients to identify conflicting tokens in experts. After that, we add a regularization loss tailored to encourage conflicting tokens routing from their current experts to other experts, for reducing interference between tokens within an expert. Our method can serve as a plug-in for diverse LVLM methods, and extensive experimental results demonstrate its effectiveness. The code will be publicly available at https://github.com/longrongyang/STGC.

Chaoxiang Cai, Longrong Yang, Kaibing Chen et al.

The mixture-of-experts (MoE), which replaces dense models with sparse architectures, has gained attention in large vision-language models (LVLMs) for achieving comparable performance with fewer activated parameters. Existing MoE frameworks for LVLMs focus on token-to-expert routing (TER), encouraging different experts to specialize in processing distinct tokens. However, these frameworks often rely on the load balancing mechanism, overlooking the inherent distributional differences between vision and language. To this end, we propose a Long-Tailed Distribution-aware Router (LTDR) for vision-language TER, tackling two challenges: (1) Distribution-aware router for modality-specific routing. We observe that language TER follows a uniform distribution, whereas vision TER exhibits a long-tailed distribution. This discrepancy necessitates distinct routing strategies tailored to each modality. (2) Enhancing expert activation for vision tail tokens. Recognizing the importance of vision tail tokens, we introduce an oversampling-like strategy by increasing the number of activated experts for these tokens. Experiments on extensive benchmarks validate the effectiveness of our approach.