arXiv Computer Vision

AdaptiveEmbed: Sample-Adaptive Multi-Vector Representation for Multimodal Retrieval

The paper introduces AdaptiveEmbed, a framework that learns sample‑adaptive multi‑vector representations for multimodal retrieval. It proposes the SAMVR setting, where each sample receives a content‑adaptive embedding set whose size is determined by its retrieval utility. The method uses Multi‑Group Contrastive Learning with set‑to‑set similarity and Utility Policy Optimization to allocate representation capacity, achieving better performance across image, text, video, and audio benchmarks.

arXiv Computer Vision
Sep 3

MARS: What Retrieval Signals Are Hidden in Multimodal Large Language Models for Text-Video Retrieval?

MARS introduces a multi‑layer, multi‑slot embedding framework for text‑video retrieval that constructs adaptive representation slots by combining hidden states from different decoder layers. By comparing corresponding text and video slots and aggregating their similarities, MARS captures fine‑grained cues that single‑token embeddings miss. A hard‑negative‑aware slot specialization objective further encourages slots to focus on discriminative matching cues, leading to state‑of‑the‑art results on four benchmarks.

By Uicheol Jung, Juyoung Hong, Geuntaek Lim, Yukyung Choi
arXiv Computer Vision
Sep 3

Allocate Before You Embed: Adaptive Visual Input Allocation for Video Embeddings

The paper introduces AllocEmbed, an allocate‑then‑embed framework that reallocates a fixed visual‑input budget across more video frames to improve retrieval performance. A lightweight allocator uses low‑cost previews to assign frame‑wise resolutions before the embedding backbone, preserving detail where it most benefits retrieval while reducing visual cost elsewhere. Retrieval‑Driven Policy Optimization (RDPO) learns the allocator directly from retrieval feedback, and the method integrates with existing systems without modifying the embedding model.

By Song Jin, Zhongtao Jiang, Chenglei Shen, Huanxuan Liao, Haozhe Chi, Zhiwei Wang, Kun Xu, Yong Liu
arXiv Machine Learning
Aug 5

VIBE: Vector Index Benchmark for Embeddings

arXiv:2505. 17810v2 Announce Type: replace Abstract: Approximate nearest neighbor (ANN) search is a performance-critical component of many machine learning pipelines, and rigorous benchmarking is essential for assessing the performance of vector indexes for ANN search.

By Elias J\"a\"asaari, Ville Hyv\"onen, Matteo Ceccarello, Teemu Roos, Martin Aum\"uller
arXiv AI
Aug 20

UMER: Unifying Embedding and Ranking via Pair-Aware Discriminative Reasoning for Universal Multimodal Retrieval

UMER is a Unified Multimodal Embedding and Ranking framework that combines contrastive embeddings with Pair‑Aware Discriminative Reasoning to improve universal multimodal retrieval. It replaces item‑wise reflection with pair‑wise comparison of query–candidate pairs, enabling explicit identification of matching and discrepancy evidence. A mutual distillation strategy transfers reliable pairwise preferences between the embedding and ranking components, and UMER achieves state‑of‑the‑art performance on the MMEB‑V2 benchmark while supporting budget‑adjustable inference.

By Libiao Chen, Xiyang Liu, Yanheng Wei, Tao Wang, Zhenyu Tang