CodeShrink: Adaptive Visual Compression for Efficient Multimodal Code Understanding

2026-07-31Computer Vision and Pattern Recognition

Computer Vision and Pattern RecognitionSoftware Engineering
AI summary

The authors present CodeShrink, a method to make code images easier for multimodal language models to process by reducing unnecessary visual data. They address inefficiencies like extra blank spaces and irrelevant code parts by using smarter layouts and an adaptive system that adjusts compression based on the specific input and task. This approach leads to fewer visual tokens being needed without losing important information, improving efficiency on tasks like code question answering and completion. Their work shows that combining layout changes, adaptive settings, and instruction-based pruning helps models understand code better while using less computing power.

Multimodal Large Language ModelsVisual TokenCode RenderingAdaptive CompressionReinforcement LearningCode Question AnsweringClone DetectionCode CompletionLayout Optimization
Authors
Wenxin Tang, Jingyu Xiao, Zhenyu Liu, Zipeng Xie, Junliang Liu, Wang Luo, Yuan Jiang, Yintong Huo, Michael Lyu
Abstract
Rendering source code as images offers a promising way to reduce the input costs of Multimodal Large Language Models (MLLMs). Adjusting image resolution can trade visual token cost against content fidelity. However, resolution scaling alone overlooks two sources of inefficiency: blank regions created by line breaks and indentation, and code regions irrelevant to the current instruction. Moreover, the best compression setting varies across inputs, tasks, and models, limiting fixed-ratio strategies. We propose CodeShrink, an adaptive visual compression framework with three components. Blank-Free Rendering replaces whitespace-dependent layouts with compact layouts and explicit structural markers, removing layout-induced tokens. Adaptive Compression Configuration uses a lightweight agent trained with reinforcement learning to predict a per-input setting that balances token efficiency and readability. Dominant Token Selection jointly analyzes the instruction and code image to prune task-irrelevant visual tokens during inference. We evaluate CodeShrink on code question answering, clone detection, and code completion. CodeShrink reduces visual token use by up to 71.2\% while matching or exceeding uncompressed text-only inputs, and consistently outperforms text-based and visual compression baselines across all three tasks. These results show that combining layout compaction, adaptive configuration, and instruction-aware pruning can make multimodal code understanding more efficient. Our code is available at https://github.com/vinsontang1/CodeShrink.