Selective Training for Large Vision Language Models via Visual Information Gain
Seulbi Lee, Sangheum Hwang
TL;DR
This work tackles language bias in large vision-language models by introducing Visual Information Gain (VIG), a perplexity-based metric that quantifies how much visual input reduces model uncertainty. VIG enables fine-grained analysis at both the sample and token levels and is used to implement a VIG-guided selective training regime that prioritizes visually informative data. Empirically, VIG-guided training yields improved visual grounding and reduced language bias across vision-understanding and hallucination benchmarks while using substantially less supervision, and it complements existing visual grounding methods without architectural changes. The approach proves particularly effective for smaller models and demonstrates increased attention to visual tokens and robustness to textual corruption, with practical considerations around the computation of VIG scores being reusable across training runs.
Abstract
Large Vision Language Models (LVLMs) have achieved remarkable progress, yet they often suffer from language bias, producing answers without relying on visual evidence. While prior work attempts to mitigate this issue through decoding strategies, architectural modifications, or curated instruction data, they typically lack a quantitative measure of how much individual training samples or tokens actually benefit from the image. In this work, we introduce Visual Information Gain (VIG), a perplexity-based metric that measures the reduction in prediction uncertainty provided by visual input. VIG enables fine-grained analysis at both sample and token levels, effectively highlighting visually grounded elements such as colors, spatial relations, and attributes. Leveraging this, we propose a VIG-guided selective training scheme that prioritizes high-VIG samples and tokens. This approach improves visual grounding and mitigates language bias, achieving superior performance with significantly reduced supervision by focusing exclusively on visually informative samples and tokens.
