CONF Melzi_WACVW_2023/IDIAP Multi-IVE: Privacy Enhancement of Multiple Soft-Biometrics in Face Embeddings Melzi, Pietro Otroshi Shahreza, Hatef Rathgeb, Christian Tolosana, Ruben Vera-Rodriguez, Ruben Fierrez, Julian Marcel, Sébastien Busch, Christoph EXTERNAL http://publications.idiap.ch/attachments/papers/2023/Melzi_WACVW_2023.pdf PUBLIC Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision 2023 https://openaccess.thecvf.com/content/WACV2023W/DVPBA/html/Melzi_Multi-IVE_Privacy_Enhancement_of_Multiple_Soft-Biometrics_in_Face_Embeddings_WACVW_2023_paper.html URL This study focuses on the protection of soft-biometric attributes related to the demographic information of individuals that can be extracted from compact representations of face images, called embeddings. We consider a state-of-the-art technology for soft-biometric privacy enhancement, Incremental Variable Elimination (IVE), and propose Multi-IVE, a new method based on IVE to secure multiple soft-biometric attributes simultaneously. Several aspects of this technology are investigated, proposing different approaches to effectively identify and discard multiple soft-biometric attributes contained in face embeddings. In particular, we consider a domain transformation using Principle Component Analysis (PCA), and apply IVE in the PCA domain. A complete analysis of the proposed Multi-IVE algorithm is carried out studying the embeddings generated by state-of-the-art face feature extractors, predicting soft-biometric attributes contained within them with multiple machine learning classifiers, and providing a cross-database evaluation. The results obtained show the possibility to simultaneously secure multiple soft-biometric attributes and support the application of embedding domain transformations before addressing the enhancement of soft-biometric privacy.