🤖 AI Summary
This work addresses the challenge of efficiently pruning large vision-language models (LVLMs), which suffer from high computational and memory costs. Existing pruning methods often fail to identify critical transitional layers that govern the evolution of multimodal representations, leading to significant performance degradation. To overcome this limitation, the study introduces topological data analysis into LVLM pruning for the first time. By modeling hidden states of each layer as point clouds, it employs simplicial complexes and Zigzag persistent homology to characterize the evolution of their topological structures across layers. This enables a quantitative measure of inter-layer topological consistency, which is then used to adaptively preserve essential transitional layers. The proposed method consistently outperforms existing pruning strategies across multiple multimodal benchmarks and maintains superior performance under varying sparsity levels.
📝 Abstract
Large Language Models (LLMs) have demonstrated strong capabilities in natural language understanding and reasoning, while recent extensions that incorporate visual inputs enable them to process multimodal information. Despite these advances, Large Vision-Language Models (LVLMs) incur substantial computational and memory costs, hindering deployment in resource-constrained scenarios. Existing layer pruning methods typically rely on local similarity metrics or static proxy signals, failing to capture the global and dynamic evolution of representations across model depth, which often leads to the removal of transition-critical layers. To address this limitation, we propose a topology-aware layer pruning framework for LVLMs. Specifically, we represent layer wise hidden states as point clouds and models their evolution using \textit{simplicial complexes}. By leveraging \textit{zigzag persistent homology}, we quantify inter-layer topological consistency and enable adaptive pruning that preserves critical representational transitions. Extensive experiments on diverse multimodal benchmarks demonstrate that the proposed framework consistently outperforms existing pruning methods across a wide range of sparsity ratios. Our code is available at https://github.com/zpc456/TopoVLM.