Visual token reduction lowers inference costs caused by extensive image features in large vision-language models (LVLMs). Unlike relevant studies that prune tokens in self-attention-only LVLMs, our work uniquely addresses cross-attention-based models, which achieve superior performance. We identify that the key-value (KV) cache size for image tokens in cross-attention layers significantly exceeds that of text tokens in self-attention layers, posing a major compute bottleneck. To mitigate this issue, we exploit the sparse nature in cross-attention maps to selectively prune redundant visual features. Our Trimmed Llama effectively reduces KV cache demands without requiring additional training. By benefiting from 50%-reduced visual features, our model can reduce inference latency and memory usage while achieving benchmark parity.
View on arXiv@article{lee2025_2504.00557,
title={ Efficient LLaMA-3.2-Vision by Trimming Cross-attended Visual Features },
author={ Jewon Lee and Ki-Ung Song and Seungmin Yang and Donguk Lim and Jaeyeon Kim and Wooksu Shin and Bo-Kyeong Kim and Yong Jae Lee and Tae-Ho Kim },
journal={arXiv preprint arXiv:2504.00557},
year={ 2025 }
}