Unlocking Few-Shot Capabilities in LVLMs via Prompt Conditioning and Head Selection

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: de Senneville, Adhemar, Bou, Xavier, Anger, Jérémy, Grompone, Rafael, Facciolo, Gabriele
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911543987273728
author de Senneville, Adhemar
Bou, Xavier
Anger, Jérémy
Grompone, Rafael
Facciolo, Gabriele
author_facet de Senneville, Adhemar
Bou, Xavier
Anger, Jérémy
Grompone, Rafael
Facciolo, Gabriele
contents Current Large Vision Language Models (LVLMs) excel at many zero-shot tasks like image captioning, visual question answering and OCR. However, these same models suffer from poor performance at image classification tasks, underperforming against CLIP-based methods. Notably, this gap is surprising because many LVLMs use CLIP-pretrained vision encoders. Yet LVLMs are not inherently limited by CLIP's architecture with independent vision and text encoders. In CLIP, this separation biases classification toward class-name matching rather than joint visual-text reasoning. In this paper we show that, despite their poor raw performance, LVLMs can improve visual feature class separability at inference using prompt conditioning, and LVLMs' internal representations, especially attention heads, can outperform the model itself at zero-shot and few-shot classification. We introduce Head Ensemble Classifiers (HEC) to bridge the performance gap between CLIP-based and LVLM-based classification methods. Inspired by Gaussian Discriminant Analysis, HEC ranks the most discriminative vision and text heads and combines them into a training-free classifier. We show that HEC achieves state-of-the-art performance in few-shot and zero-shot classification across 12 datasets.
format Preprint
id arxiv_https___arxiv_org_abs_2603_24181
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Unlocking Few-Shot Capabilities in LVLMs via Prompt Conditioning and Head Selection
de Senneville, Adhemar
Bou, Xavier
Anger, Jérémy
Grompone, Rafael
Facciolo, Gabriele
Computer Vision and Pattern Recognition
Current Large Vision Language Models (LVLMs) excel at many zero-shot tasks like image captioning, visual question answering and OCR. However, these same models suffer from poor performance at image classification tasks, underperforming against CLIP-based methods. Notably, this gap is surprising because many LVLMs use CLIP-pretrained vision encoders. Yet LVLMs are not inherently limited by CLIP's architecture with independent vision and text encoders. In CLIP, this separation biases classification toward class-name matching rather than joint visual-text reasoning. In this paper we show that, despite their poor raw performance, LVLMs can improve visual feature class separability at inference using prompt conditioning, and LVLMs' internal representations, especially attention heads, can outperform the model itself at zero-shot and few-shot classification. We introduce Head Ensemble Classifiers (HEC) to bridge the performance gap between CLIP-based and LVLM-based classification methods. Inspired by Gaussian Discriminant Analysis, HEC ranks the most discriminative vision and text heads and combines them into a training-free classifier. We show that HEC achieves state-of-the-art performance in few-shot and zero-shot classification across 12 datasets.
title Unlocking Few-Shot Capabilities in LVLMs via Prompt Conditioning and Head Selection
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2603.24181