Q-Bench-Portrait: Benchmarking Multimodal Large Language Models on Portrait Image Quality Perception
Sijing Wu, Yunhao Li, Zicheng Zhang, Qi Jia, Xinyue Li, Huiyu Duan, Xiongkuo Min, Guangtao Zhai
TL;DR
The paper addresses the lack of portrait-specific, low-level visual quality benchmarks for multimodal large language models (MLLMs). It introduces Q-Bench-Portrait, a holistic dataset of 2,765 image–question–answer triplets drawn from 17 portrait sources, organized around three quality dimensions (technical distortions, AIGC-specific distortions, aesthetics) and four question types (single-choice, multiple-choice, true/false, open-ended) at global and local scopes. By evaluating 25 MLLMs (open- and closed-source), the study shows that while some open-source models approach closed-model performance, all models struggle with fine-grained, portrait-specific quality perception, especially for AI-generated and computer-graphics portraits and for local questions. The benchmark, constructed with GPT-assisted human-in-the-loop methods and Gemini-generated captions, provides a rigorous framework to advance portrait-aware MLLMs and guides future improvements in perceptual quality assessment for human-centric imagery.
Abstract
Recent advances in multimodal large language models (MLLMs) have demonstrated impressive performance on existing low-level vision benchmarks, which primarily focus on generic images. However, their capabilities to perceive and assess portrait images, a domain characterized by distinct structural and perceptual properties, remain largely underexplored. To this end, we introduce Q-Bench-Portrait, the first holistic benchmark specifically designed for portrait image quality perception, comprising 2,765 image-question-answer triplets and featuring (1) diverse portrait image sources, including natural, synthetic distortion, AI-generated, artistic, and computer graphics images; (2) comprehensive quality dimensions, covering technical distortions, AIGC-specific distortions, and aesthetics; and (3) a range of question formats, including single-choice, multiple-choice, true/false, and open-ended questions, at both global and local levels. Based on Q-Bench-Portrait, we evaluate 20 open-source and 5 closed-source MLLMs, revealing that although current models demonstrate some competence in portrait image perception, their performance remains limited and imprecise, with a clear gap relative to human judgments. We hope that the proposed benchmark will foster further research into enhancing the portrait image perception capabilities of both general-purpose and domain-specific MLLMs.
