Reroute:面向视觉语言模型的可恢复视觉Token路由方法
阅读原文· arxiv.org视觉语言模型(VLM)将图像投影为大量视觉token,导致推理时注意力计算与KV缓存开销高昂。现有方法遵循“排序‑移除”范式,但token重要性随解码器深度变化,早期丢弃的token可能在后续层变得关键。Reroute是一种无需训练的可插拔模块,将永久移除替换为可恢复路由:被延迟的token绕过当前解码阶段,在下一路由决策时重新进入候选池。在LLaVA‑1.5与Qwen骨干上对FastV、PDrop和Nüwa变体的实验表明,Reroute在激进token压缩下提升了grounding能力,同时保持通用VQA性能。
Vision-language models (VLMs) project images into hundreds to thousands of visual tokens, making decoder inference expensive in both attention computation and KV-cache memory. Existing visual-token reduction methods largely follow a rank-and-remove paradigm: they score visual tokens, keep a compact subset, and permanently discard the rest. We show that this irreversible action is fragile because visual-token importance changes across decoder depth; tokens ranked low at one stage may become relevant in later layers, especially for grounding-sensitive queries. We propose Reroute, a training-free plug-in that replaces removal with recoverable routing. At each routing stage, selected vision tokens pass through decoder blocks, while deferred tokens bypass the stage and re-enter the candidate pool at the next routing decision. Reroute reuses existing attention-score ranking rules and stage-wise schedules, preserving the theoretical TFLOPs and KV-cache budget class of the pruning method it augments. Across FastV, PDrop, and Nüwa variants on LLaVA-1.5 and Qwen backbones, reroute improves grounding under aggressive token reduction while maintaining general VQA performance. These results suggest that VLM token reduction should not be viewed only as irreversible pruning, but also as recoverable routing. The code can be found here: https://github.com/elmma/mllm-reroute/