CONF sanderson:2005:icita/IDIAP On Accuracy/Robustness/Complexity Trade-Offs in Face Verification Sanderson, Conrad Cardinaux, Fabien Bengio, Samy EXTERNAL https://publications.idiap.ch/attachments/reports/2005/sanderson_2005_icita.pdf PUBLIC https://publications.idiap.ch/index.php/publications/showcite/cardinaux04-74 Related documents IEEE International Conference on Information Technology and Applications, ICITA 2005 REPORT cardinaux04-74/IDIAP On Performance / Robustness / Complexity Trade-Offs in Face Verification Sanderson, Conrad Cardinaux, Fabien Bengio, Samy EXTERNAL https://publications.idiap.ch/attachments/reports/2004/rr04-74.pdf PUBLIC Idiap-RR-74-2004 2004 IDIAP In much of the literature devoted to face recognition, experiments are performed with controlled images (e.g. manual face localization, controlled lighting, background and pose); however, a practical recognition system has to be robust to more challenging conditions. In this paper we first evaluate, on the relatively difficult BANCA database, the performance, robustness and complexity of Gaussian Mixture Model (GMM,',','), 1D- and pseudo-2D Hidden Markov Model (HMM) based systems, using both manual and automatic face localization. We also propose to extend the GMM approach through the use of local features with embedded positional information, increasing performance without sacrificing its low complexity. Experiments show that good performance on manually located faces is not necessarily indicative of good performance on automatically located faces (which are imperfectly located). The deciding factor is shown to be the degree of constraints placed on spatial relations between face parts. Methods which utilize rigid constraints have poor robustness compared to methods which have relaxed constraints. Furthermore, we show that while the pseudo-2D HMM approach has the best overall performance, classification time on current hardware makes it impractical. The best trade-off in terms of complexity, robustness and discrimination performance is achieved by the extended GMM approach.