Visual Affect Analysis: Predicting Emotions of Image Viewers with Vision-Language Models
Filip Nowicki, Hubert Marciniak, Jakub Łączkowski, Krzysztof Jassem, Tomasz Górecki, Vimala Balakrishnan, Desmond C. Ong, Maciej Behnke
TL;DR
This work benchmarks vision–language architectures on three psychometric affective image datasets (IAPS, NAPS, LAI-GAI) to evaluate how well zero-shot VLM outputs align with human ratings across discrete emotions and continuous affective dimensions. It demonstrates that while VLMs can classify core emotions with reasonable accuracy and correlate with human judgments on intensity, they exhibit systematic biases (notably in arousal) and struggle with anger and surprise, indicating limited nuanced understanding. Rater-conditioned prompting yields only modest, inconsistent gains, suggesting current prompts and demographic conditioning are not robust strategies for improving affective prediction. The study highlights the potential of VLMs as supportive tools for affective science (e.g., coarse annotations and pre-screening) while emphasizing the need for richer datasets, task-specific prompting, and calibration to move toward reliable, scalable affective assessment.
Abstract
Vision-language models (VLMs) show promise as tools for inferring affect from visual stimuli at scale; it is not yet clear how closely their outputs align with human affective ratings. We benchmarked nine VLMs, ranging from state-of-the-art proprietary models to open-source models, on three psycho-metrically validated affective image datasets: the International Affective Picture System, the Nencki Affective Picture System, and the Library of AI-Generated Affective Images. The models performed two tasks in the zero-shot setting: (i) top-emotion classification (selecting the strongest discrete emotion elicited by an image) and (ii) continuous prediction of human ratings on 1-7/9 Likert scales for discrete emotion categories and affective dimensions. We also evaluated the impact of rater-conditioned prompting on the LAI-GAI dataset using de-identified participant metadata. The results show good performance in discrete emotion classification, with accuracies typically ranging from 60% to 80% on six-emotion labels and from 60% to 75% on a more challenging 12-category task. The predictions of anger and surprise had the lowest accuracy in all datasets. For continuous rating prediction, models showed moderate to strong alignment with humans (r > 0.75) but also exhibited consistent biases, notably weaker performance on arousal, and a tendency to overestimate response strength. Rater-conditioned prompting resulted in only small, inconsistent changes in predictions. Overall, VLMs capture broad affective trends but lack the nuance found in validated psychological ratings, highlighting their potential and current limitations for affective computing and mental health-related applications.
