Deep Pre-Alignment for VLMs
Quick Take
Deep Pre-Alignment enhances Vision Language Models by ensuring visual features align deeply with text space.
Key Points
- DPA replaces ViT encoder with a small VLM perceiver.
- Achieves 1.9 point improvement on 4B parameter models.
- Reduces language capability forgetting by 32.9%.
📖 Reader Mode
~2 min readAbstract:Most Vision Language Models (VLMs) directly map outputs from ViT encoders to the LLM via a lightweight projector. While effective, recent analysis suggests this architecture suffers from an alignment challenge: visual features remain distant from the text space in the initial layers of the LLM, forcing the model to waste critical depth~\cite{zhang-etal-2024-investigating,artzy-schwartz-2024-attend} on superficial modality alignment rather than deep understanding and complex reasoning. In this work, we propose Deep Pre-Alignment (DPA), a novel architecture that replaces the standard ViT encoder with a small VLM as perceiver, ensuring visual features are deeply aligned with the text space of the target large language model. Comprehensive experiments demonstrate the effectiveness of DPA. On the 4B parameter scale, DPA outperforms baselines by 1.9 points across 8 multimodal benchmarks, with gains widening to 3.0 points at the 32B scale. Moreover, by offloading alignment to the perceiver, DPA achieves a 32.9\% reduction in language capability forgetting over 3 text benchmarks. We further demonstrate that these gains are consistent across different LLM families including Qwen3 and LLaMA 3.2, highlighting the generality of our approach. Beyond performance, DPA also offers a seamless upgrade path for current VLM development, requiring only a modular replacement for the visual encoder with marginal computation overhead.
| Comments: | Accepted by ICML 2026. Project Website: this https URL |
| Subjects: | Computer Vision and Pattern Recognition (cs.CV) |
| Cite as: | arXiv:2605.15300 [cs.CV] |
| (or arXiv:2605.15300v1 [cs.CV] for this version) | |
| https://doi.org/10.48550/arXiv.2605.15300 arXiv-issued DOI via DataCite (pending registration) |
Submission history
From: Tianyu Yu [view email]
[v1]
Thu, 14 May 2026 18:14:15 UTC (1,382 KB)
— Originally published at arxiv.org
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