๐ค AI Summary
Large vision-language models (LVLMs) overly rely on deepest-layer visual features while neglecting complementary information across intermediate layers. Method: We propose an instruction-guided dynamic visual feature aggregation mechanismโthe first of its kind to enable instruction-driven, adaptive selection, weighting, and cross-layer interaction of multi-depth visual features without increasing the number of visual tokens. Leveraging task-aware attention aggregation and instruction-conditioned gating, the method jointly optimizes fine-grained perception (via low-level features) and semantic understanding (via mid- to high-level features). Contribution/Results: Our approach achieves significant performance gains across 18 benchmarks spanning six diverse vision-language tasks, demonstrating both the effectiveness and strong generalizability of dynamic, hierarchical visual feature utilization.
๐ Abstract
Large Vision-Language Models (LVLMs) have achieved remarkable success in a wide range of multimodal tasks by integrating pre-trained vision encoders and large language models. However, current LVLMs primarily rely on visual features extracted from the final layers of the vision encoder, overlooking the complementary information available in shallower layers. While recent approaches have explored the use of multilayer visual features in LVLMs, they tend to be task-agnostic and fail to examine the dependencies of hierarchical visual features on specific tasks. To address these gaps, we systematically investigate the contributions of visual features from different encoder layers using 18 benchmarks spanning 6 task categories. Our findings reveal that multilayer features provide complementary strengths with varying task dependencies, and uniform fusion leads to suboptimal performance. Building on these insights, we propose the instruction-guided vision aggregator, a module that dynamically integrates multi-layer visual features based on textual instructions, without increasing the number of visual tokens. Extensive evaluations demonstrate the superior performance of our method. Additionally, an in-depth analysis of the aggregator's behavior highlights the dominance of mid-to-high-level features in semantic-rich tasks and the critical role of low-level features in fine-grained perception.