cs.CVMar 22, 2026

Test-Time Adaptation via Cache Personalization for Facial Expression Recognition in Videos

Authors: Masoumeh Sharafi, Muhammad Osama Zeeshan, Soufiane Belharbi, Alessandro Lameiras Koerich, Marco Pedersoli, Eric Granger

Organizations: LIVIA, Department of Systems Engineering, ´ETS Montreal, Canada · LIVIA, Department of Software and IT Engineering, ´ETS Montreal, Canada

Abstract

Facial expression recognition (FER) in videos requires model personalization to capture considerable variation across subjects. Vision-language models (VLMs) offer strong transfer through image-text alignment, but their performance can degrade under inter-subject distribution shifts. Test-time adaptation (TTA) can mitigate this challenge, yet most state-of-the-art methods rely on unsupervised parameter optimization, introducing computational overhead that limits real-world deployment. This paper introduces TTA through Cache Personalization (TTA-CaP), a gradient-free, cache-based method for cost-effective personalization of VLMs in video FER. Unlike prior cache-based TTA methods that rely solely on dynamic memories of test samples and may drift because of noisy pseudo-labels, TTA-CaP employs three complementary caches: a personalized static cache constructed through feature-statistics matching, a positive target cache containing reliable subject-specific samples, and a negative target cache containing low-confidence cases as negative evidence. A tri-gate mechanism prevents cache corruption by controlling updates according to temporal stability, confidence, and consistency with the personalized static cache. The caches jointly provide subject-matched positive and negative evidence for robust personalization. TTA-CaP further refines predictions through embedding fusion, supporting temporally stable video-level predictions. Experiments on BioVid, StressID, and BAH show that TTA-CaP outperforms state-of-the-art TTA methods under subject-specific and environmental shifts while maintaining low computational and memory overhead. Our code is publicly available at https://github.com/MasoumehSharafi/TTA-CaP.

Figures & tables

Appendix figures & tables17 assets

Supplementary material from the paper’s appendix.

Appendix

Explore similar work

CardsList
  1. Test-Time Adaptation with Online Personalized Energy-Based Cache for Fine-Grained Video Expression Recognition

    Aug 6, 2026Masoumeh Sharafi, Muhammad Osama Zeeshan, Soufiane Belharbi +3Test-Time AdaptationVLM Adaptation

  2. Evaluating Test-Time Adaptation For Facial Expression Recognition Under Natural Cross-Dataset Distribution Shifts

    Mar 20, 2026John Turnbull, Shivam Grover, Amin Jalali +1Test-Time AdaptationDistribution Shift Robustness

  3. CLIP-AUTT: Test-Time Personalization with Action Unit Prompting for Fine-Grained Video Emotion Recognition

    Mar 30, 2026Muhammad Osama Zeeshan, Masoumeh Sharafi, Benoit Savary +3VLM AdaptationFacial Expression Recognition