ArtFRD: A Fisher-Rao Mixture Metric for Generative Model Aesthetic Evaluation

Recent advances in generative modeling have enabled the synthesis of high-quality artistic images. Nevertheless, systematic evaluation of generative models from an aesthetic standpoint is still lacking, which hinders progress in artistic image synthesis. Existing evaluation metrics, such as Fréchet Inception Distance (FID) and CMMD, struggle with aesthetic assessment: they rely on pretrained visual features that overlook nuanced artistic attributes and employ distance functions ill-suited for modeling the diverse, multi-modal distribution of artistic styles. To address these limitations, we propose ArtFRD, a metric specifically designed for generative aesthetic evaluation. Grounded in aesthetic theory, ArtFRD extracts visual features along four key aesthetic dimensions-brushstroke, composition, lighting, and color-to capture fine-grained artistic properties. To model the multi-modal nature of artistic styles, we adopt a Gaussian Mixture Model assumption and derive an efficient approximation of the Fisher-Rao distance, which serves as the final evaluation score. Extensive experiments demonstrate that ArtFRD aligns significantly better with human aesthetic judgments than existing metrics, even across a wide range of artistic styles. These results highlight its potential as a robust and interpretable foundation for future research in generative aesthetic evaluation.