Multimodal models

Vision-language models, speech and cross-modal systems that read, look and listen in the same forward pass.

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arXiv Computer Vision
Aug 31

3D MRI-Based Alzheimer's Disease Classification Using Multi-Modal 3D CNN with Leakage-Aware Subject-Level Evaluation

The paper presents a multimodal 3D convolutional neural network that classifies Alzheimer’s disease using raw OASIS 1 MRI volumes. It fuses structural T1 images with gray matter, white matter, and cerebrospinal fluid probability maps to capture complementary neuroanatomical information. Evaluated with 5‑fold subject‑level cross‑validation, the model achieves a mean accuracy of 72.34 % and an ROC AUC of 0.7781, with GradCAM visualizations highlighting anatomically relevant regions such as the medial temporal lobe and ventricles.

By Md Sifat, Sania Akter, Akif Islam, Md. Ekramul Hamid, Abu Saleh Musa Miah, Najmul Hassan, Md Abdur Rahim, Jungpil Shin
arXiv Computer Vision
Aug 31

HyperVision: A Channel-Adaptive Ground-Based Hyperspectral Vision Pre-trained Backbone

HyperVision introduces the first ground‑based hyperspectral pre‑trained backbone, addressing challenges of varying spectral configurations, limited annotations, and dataset diversity. It employs a channel‑adaptive dynamic embedding to unify heterogeneous inputs, a multi‑source pseudo‑labeling strategy combining SAM2 spatial cues with HyperFree spectral details, and cross‑modal knowledge distillation from a pre‑trained RGB vision model. Trained on 15k images from 26 datasets, HyperVision achieves significant improvements—up to 16.3% relative gain in hyperspectral semantic segmentation, 2.1% in object tracking AUC, and 35.5% reduction in salient object detection MAE—while requiring only head‑only adaptation.

By Guanyiman Fu, Jingtao Li, Zihang Cheng, Zhuanfeng Li, Diqi Chen, Yan Xu, Xiangyu Liu, Fengchao Xiong, Jianfeng Lu, Chengrong Chen, Jun Zhou
arXiv Computation and Language
Aug 31

CamoDocs: A Poisoning Attack Against Retrieval-Augmented Language Models Using Camouflaged Documents

arXiv:2608. 28389v1 Announce Type: cross Abstract: Retrieval-augmented generation (RAG) augments LLMs with external documents, but public or user-editable sources expose RAG systems to data poisoning: attackers can inject malicious documents to steer outputs toward targeted answers.

By Jaewon Jung, Haizhong Zheng, Hongsun Jang, Jaeyong Song, Beidi Chen, Jinho Lee
arXiv Computer Vision
Aug 31

Iron: Intent-Aligned and Retrospective Dual Learning Framework for Enhancing Generalist Virtual Agents

Iron is a new framework for training generalist virtual agents that aligns low‑level actions with high‑level intents using a stepwise cycle‑consistent reward. It also repurposes failed trajectories through a hindsight reproduction mechanism to improve learning efficiency and task diversity. Experiments show Iron‑trained agents outperform those trained with three times more data, achieving a 25.06% relative improvement on unseen web tasks and better performance on complex tasks.

By Jiahe Ying, Wendong Bu, Kaihang Pan, Bingchen Miao, Siyu Chen, Wen Wang, Xueming Jiang, Juncheng Li, Siliang Tang
arXiv Computer Vision
Aug 31

Dynamic Alignment Compensation for Hallucination Mitigation in Large Vision-Language Models

The paper introduces Dynamic Alignment Compensation (DAC), a training‑free inference‑time technique designed to reduce hallucinations in Large Vision‑Language Models (LVLMs). DAC monitors cross‑modal representation drift across decoder layers and generation steps, applying lightweight residual compensation through Layer‑wise Semantic Compensation and Sequential Semantic Correction. Experiments on nine multimodal benchmarks across various LVLM backbones demonstrate that DAC consistently lowers hallucination rates while preserving overall performance.

By Kairong Yu, Zixin Zhu, Le Yu, Hongwei Wang
arXiv Machine Learning
Aug 31

SemEnrich: Self-Supervised Semantic Enrichment of Radiology Reports for Vision-Language Learning

SemEnrich introduces a self‑supervised method to enrich radiology reports by clustering sentences semantically and adding positive or neutral observations from different clusters. The enriched data consistently improves supervised fine‑tuning across multiple vision‑language metrics, with gains ranging from 3% to 7.5% on COMET, Bert, Sentence Bleu, CheXbert‑F1, and RadGraph‑F1. The authors also demonstrate that incorporating cluster information into the reward design for GRPO training yields additional performance boosts.

By Halil Ibrahim Gulluk, Olivier Gevaert
arXiv Computer Vision
Aug 31

Beyond Data Scaling: Representation-Centric Continued Pre-training for Vision-Language-Action Models

The paper introduces VLAct, a Vision‑Language‑Action model that focuses on representation‑centric continued pre‑training rather than merely scaling robot data. VLAct is trained on diverse, multi‑embodiment robot data and preserves a broad VLM prior while encouraging shared action semantics across embodiments. Experiments across simulation, real‑world, and unseen‑embodiment settings show that VLAct consistently outperforms existing industrial VLA systems, achieving high success rates with only a modest compute budget and open‑source data.

By Senqiao Yang, Chengyao Wang, Yuxin Chen, Zixuan Wang, Longxiang Tang, Haokun Gui, Jinhui Ye, Changsheng Lu, Xiaoyang Wu, Mingkang Zhu, Pengguang Chen, Shu Liu, Zhuotao Tian, Hengshuang Zhao, Bei Yu, Jiaya Jia
arXiv Computation and Language
Aug 31

Compositional Failure in Audio-Visual LLMs: Late-Layer Prior Dominance Under Cross-modal Conflict

The paper investigates audio‑visual conflict as a test of compositional generalization for audio‑visual large language models (AV‑LLMs). It shows that models such as VideoLLaMA 2‑7B‑AV and InternVideo2 exhibit a failure mode called prior dominance, where late‑layer commitment to an internally preferred answer pattern overrides conflicting audio‑visual inputs, leading to significant accuracy drops. Mechanistic analysis reveals that this commitment is concentrated around layer 25.5 and that stronger temporal alignment shifts answer bias but does not resolve the conflict.

By Adarsh Sudheer, David Li, Omar Elbanna, Ishaan Kodarapu, Arjun Bahuguna, Vasu Sharma
arXiv AI
Aug 28

A Multi-Modal AI Framework for Real-Time Queue Prediction, Management and Optimisation in Intelligent Border Control Systems

The paper proposes a multi‑modal AI framework for real‑time queue prediction, management, and resource optimisation in border control systems. It integrates heterogeneous data sources using LSTM networks for forecasting and applies Model Predictive Control and scheduling optimisation to generate actionable policies for officers. Evaluation on synthetic traffic data shows up to 35% reduction in prediction error, 30% lower average waiting time, and nearly 20% higher throughput compared to ARIMA and rule‑based methods.

By Varvara Mama, Eleni Veroni, Nikolaos Kapsalis, Christos D. Nikolopoulos, Anargyros T. Baklezos
arXiv AI
Aug 28

Position Is All You Need: A Free Lunch Token Compression Strategy for MLLM-based Referring Expression Segmentation

The paper introduces PAYN, a training‑free token compression strategy for Multimodal Large Language Model (MLLM) based Referring Expression Segmentation (RES). By preserving original position embeddings and local spatial structures, PAYN retains tokens that are evenly distributed across neighboring regions, thereby maintaining spatial relational consistency. Experiments on multiple RES benchmarks show that PAYN outperforms existing token compression methods, confirming that position information alone is sufficient for effective compression in this task.

By Yuhan Liu, Yixiong Zou, Yuhua Li, Ruixuan Li
arXiv Computer Vision
Aug 28

Checkerboard: Closed-Form and Data-Independent Trigger Design for Clean-Label Backdoor Attacks

The paper introduces Checkerboard, a clean‑label backdoor attack that uses a closed‑form, data‑independent trigger design based on an input‑space Fisher‑separability objective and a ridge four‑neighbor local‑smoothness prior. This approach yields a pixel‑wise checkerboard trigger without requiring data access, surrogate model training, or iterative optimization, and it outperforms existing norm‑bounded clean‑label attacks across four benchmark datasets. On CIFAR‑10, poisoning 20 samples with a 10/255 perturbation achieves a 95.72% attack success rate, while on IN‑100 a 0.4% global poisoning rate yields over 83% ASR without harming clean accuracy, and the attack remains robust against state‑of‑the‑art defenses.

By Yi Yang, Jinyang Huang, Binbin Liu, Feng-Qi Cui, Xiaokang Zhou, Haiming Jin, Zhi Liu, Jie Zhang, Meng Li