CARES: Context-Aware Resolution Selector for VLMs
Moshe Kimhi, Nimrod Shabtay, Raja Giryes, Chaim Baskin, Eli Schwartz
TL;DR
CARES introduces a lightweight, model-agnostic preprocessor that predicts the minimal sufficient input resolution for a given image–query pair, reducing token counts and compute prior to vision–language model tokenization. It uses a compact proxy VLM to extract joint image–text features from a low-resolution pass, then classifies among a discrete resolution menu and interpolates a continuous resolution at inference. Ground-truth resolutions are obtained via multi-resolution rollouts and an ANLS-based sufficiency rule, enabling efficient supervision without changing target VLMs. Across five multimodal benchmarks and multiple backbones, CARES achieves 70–85% prefill FLOPs savings with minimal to no drop in accuracy, demonstrating a practical, plug-and-play path to scalable VLM deployment. This front-end resolution control complements post-tokenization compression techniques and opens avenues for finer-grained, query-aware input allocation in multimodal systems.
Abstract
Large vision-language models (VLMs) commonly process images at native or high resolution to remain effective across tasks. This inflates visual tokens ofter to 97-99% of total tokens, resulting in high compute and latency, even when low-resolution images would suffice. We introduce \emph{CARES}-a \textbf{C}ontext-\textbf{A}ware \textbf{R}esolution \textbf{S}elector, a lightweight preprocessing module that, given an image-query pair, predicts the \emph{minimal} sufficient input resolution. CARES uses a compact VLM (350M) to extract features and predict when a target pretrained VLM's response converges to its peak ability to answer correctly. Though trained as a discrete classifier over a set of optional resolutions, CARES interpolates continuous resolutions at inference for fine-grained control. Across five multimodal benchmarks spanning documents and natural images, as well as diverse target VLMs, CARES preserves task performance while reducing compute by up to 80%.
