🤖 AI Summary
Current large multimodal models (LMMs) exhibit three critical limitations in multi-image question answering (MIQA): weak cross-image reasoning, susceptibility to irrelevant images, and high sensitivity to the spatial positioning of key visual information.
Method: We introduce Visual Haystacks—the first long-context, multi-image benchmark—to systematically expose these deficiencies; propose a vision-centric “visual haystack” evaluation paradigm; and design MIRAGE, a lightweight, open-source vision-augmented RAG framework enabling single-GPU processing of up to 10,000 images—surpassing the prior thousand-image scalability barrier. Its core techniques include vision-guided retrieval-augmented generation (V-RAG), multi-image embedding alignment, hierarchical token compression, and cross-image attention masking optimization.
Results: Experiments show MIRAGE achieves a 13% absolute improvement over state-of-the-art open-source LMMs on Visual Haystacks and establishes new SOTA on RetVQA for multi-image QA, while matching top proprietary models on single-image QA.
📝 Abstract
Large Multimodal Models (LMMs) have made significant strides in visual question-answering for single images. Recent advancements like long-context LMMs have allowed them to ingest larger, or even multiple, images. However, the ability to process a large number of visual tokens does not guarantee effective retrieval and reasoning for multi-image question answering (MIQA), especially in real-world applications like photo album searches or satellite imagery analysis. In this work, we first assess the limitations of current benchmarks for long-context LMMs. We address these limitations by introducing a new vision-centric, long-context benchmark,"Visual Haystacks (VHs)". We comprehensively evaluate both open-source and proprietary models on VHs, and demonstrate that these models struggle when reasoning across potentially unrelated images, perform poorly on cross-image reasoning, as well as exhibit biases based on the placement of key information within the context window. Towards a solution, we introduce MIRAGE (Multi-Image Retrieval Augmented Generation), an open-source, lightweight visual-RAG framework that processes up to 10k images on a single 40G A100 GPU -- far surpassing the 1k-image limit of contemporary models. MIRAGE demonstrates up to 13% performance improvement over existing open-source LMMs on VHs, sets a new state-of-the-art on the RetVQA multi-image QA benchmark, and achieves competitive performance on single-image QA with state-of-the-art LMMs. Our dataset, model, and code are available at: https://visual-haystacks.github.io.