Abstract: The face identification is a non invasive method, representing a great advantage against other biometric systems, which request the user’s collaboration. Two types of methods were proposed to extract face features for expression recognition, namely the image-based and the model-based methods. They differ in the way to process the images.
Model-based methods are a popular way to extract features. This type of systems is quite hard to work with, due to the fact that people constantly change their expression, even with just speaking. In fact, the typical limitations for this type of systems are that the face should be inside a certain margin of rotation (smaller than 15 degrees), and that the expression should not change so much. Model-based methods should only be applied when the subject cooperates for the recognition. Inside this type of study, a great variety of references can be found. Image-based methods are an alternative to extract facial expression features. They create a transformation, to pass from the spatial domain (image) to another transformed domain. This modality allows to research with a greater margin of variation on the faces, since for this method it is not necessary to have some characteristic points. The advantage of this type of techniques is that it is able to distinguish persons regardless of wearing eyeglasses or light beard, and even permits a greater degree of rotation of the head in all directions.

Brief Biography of the Speaker:
Dr. Carlos M. Travieso-Gonzalez was born in Spain in 1971. He received the M.Sc. degree in 1997 in Telecommunication Engineering at Polytechnic University of Catalonia (UPC), Spain. Besides, he received Ph.D. degree in 2002 at University of Las Palmas de Gran Canaria (ULPGC-Spain). He is an Associate Professor from 2001 in ULPGC, teaching subjects on signal processing and learning theory. His research lines are biometric systems, classification system, medical signal processing, environmental intelligence, and data mining. He has researched in 22 International and Spanish Research Projects, some of them as head researcher. He has 140 papers published in international journals and conferences. He has been reviewer in different international journals and conferences since 2001. He is Image Processing Technical IASTED Committee Member. He is Vice-Dean from 2004 in Higher Technical School of Telecommunication Engineers in ULPGC.