Saved in:
Bibliographic Details
Main Authors: Avogaro, Niccolo, Frick, Thomas, Rigotti, Mattia, Bartezzaghi, Andrea, Janicki, Filip, Malossi, Cristiano, Schindler, Konrad, Assaf, Roy
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2503.19647
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917252937285632
author Avogaro, Niccolo
Frick, Thomas
Rigotti, Mattia
Bartezzaghi, Andrea
Janicki, Filip
Malossi, Cristiano
Schindler, Konrad
Assaf, Roy
author_facet Avogaro, Niccolo
Frick, Thomas
Rigotti, Mattia
Bartezzaghi, Andrea
Janicki, Filip
Malossi, Cristiano
Schindler, Konrad
Assaf, Roy
contents Large Vision-Language Models (VLMs) are increasingly being regarded as foundation models that can be instructed to solve diverse tasks by prompting, without task-specific training. We examine the seemingly obvious question: how to effectively prompt VLMs for semantic segmentation. To that end, we systematically evaluate the segmentation performance of several recent models guided by either text or visual prompts on the out-of-distribution MESS dataset collection. We introduce a scalable prompting scheme, few-shot prompted semantic segmentation, inspired by open-vocabulary segmentation and few-shot learning. It turns out that VLMs lag far behind specialist models trained for a specific segmentation task, by about 30% on average on the Intersection-over-Union metric. Moreover, we find that text prompts and visual prompts are complementary: each one of the two modes fails on many examples that the other one can solve. Our analysis suggests that being able to anticipate the most effective prompt modality can lead to a 11% improvement in performance. Motivated by our findings, we propose PromptMatcher, a remarkably simple training-free baseline that combines both text and visual prompts, achieving state-of-the-art results outperforming the best text-prompted VLM by 2.5%, and the top visual-prompted VLM by 3.5% on few-shot prompted semantic segmentation.
format Preprint
id arxiv_https___arxiv_org_abs_2503_19647
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Show or Tell? Effectively prompting Vision-Language Models for semantic segmentation
Avogaro, Niccolo
Frick, Thomas
Rigotti, Mattia
Bartezzaghi, Andrea
Janicki, Filip
Malossi, Cristiano
Schindler, Konrad
Assaf, Roy
Computer Vision and Pattern Recognition
Artificial Intelligence
Large Vision-Language Models (VLMs) are increasingly being regarded as foundation models that can be instructed to solve diverse tasks by prompting, without task-specific training. We examine the seemingly obvious question: how to effectively prompt VLMs for semantic segmentation. To that end, we systematically evaluate the segmentation performance of several recent models guided by either text or visual prompts on the out-of-distribution MESS dataset collection. We introduce a scalable prompting scheme, few-shot prompted semantic segmentation, inspired by open-vocabulary segmentation and few-shot learning. It turns out that VLMs lag far behind specialist models trained for a specific segmentation task, by about 30% on average on the Intersection-over-Union metric. Moreover, we find that text prompts and visual prompts are complementary: each one of the two modes fails on many examples that the other one can solve. Our analysis suggests that being able to anticipate the most effective prompt modality can lead to a 11% improvement in performance. Motivated by our findings, we propose PromptMatcher, a remarkably simple training-free baseline that combines both text and visual prompts, achieving state-of-the-art results outperforming the best text-prompted VLM by 2.5%, and the top visual-prompted VLM by 3.5% on few-shot prompted semantic segmentation.
title Show or Tell? Effectively prompting Vision-Language Models for semantic segmentation
topic Computer Vision and Pattern Recognition
Artificial Intelligence
url https://arxiv.org/abs/2503.19647