PrimateFace: A Machine Learning Resource for Automated Face Analysis in Human and Non-human Primates

Parodi, F.; Matelsky, J.; Lamacchia, A.; Segado, M.; Jiang, Y.; Regla-Vargas, A.; Sofi, L.; Kimock, C.; Waller, B. M.; Platt, M.; Kording, K. P.

doi:10.1101/2025.08.12.669927

bioRxiv · 10.1101/2025.08.12.669927

PrimateFace: A Machine Learning Resource for Automated Face Analysis in Human and Non-human Primates

Parodi, F.·Matelsky, J.·Lamacchia, A.·Segado, M.·Jiang, Y.·Regla-Vargas, A.·Sofi, L.·Kimock, C.·Waller, B. M.·Platt, M.·Kording, K. P.

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Abstract

Machine learning has revolutionized human face analysis, but equivalent tools for non-human primates remain limited and species-specific, hindering progress in neuroscience, anthropology, and conservation. Here, we present PrimateFace, a comprehensive, cross-species platform for primate facial analysis comprising a systematically curated dataset of 260,000+ images spanning over 60 genera, including a genus-balanced subset of 60,000 images, annotated with bounding boxes and facial landmark configurations. Face detection and facial landmark estimation models trained on PrimateFace achieve high cross-species performance, from tarsiers to gorillas, achieving performance comparable to baseline models trained exclusively on human data (0.34 vs. 0.39 mAP for face detection; 0.061 vs. 0.053 normalized landmark error), demonstrating the generalization benefits of cross-species training. PrimateFace enables diverse downstream applications including individual recognition, gaze analysis, and automated extraction of stereotyped (e.g., lip-smacking) and subtle (e.g., soft left turn) facial movements. PrimateFace provides a standardized platform for facial phenotyping across the primate order, empowering data-driven studies that advance the health and well-being of human and non-human primates. All models, notebooks, and data can be found at github.com/KordingLab/PrimateFace.

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Parodi, F., Matelsky, J., Lamacchia, A., Segado, M., Jiang, Y., Regla-Vargas, A., Sofi, L., Kimock, C., Waller, B. M., Platt, M., Kording, K. P.. 2025-08-15. PrimateFace: A Machine Learning Resource for Automated Face Analysis in Human and Non-human Primates. https://doi.org/10.1101/2025.08.12.669927

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