As one of the most important applications of image analysis and understanding, face recognition has recently received significant attention, especially during the past 10 years. There are at least two reasons for this trend: the first is the wide range of commercial and law-enforcement applications, and the second is the availability of feasible technologies.
Though machine recognition of faces has reached a certain level of maturity after more than 35 years of research, e.g., in terms of the number of subjects to be recognized, technological challenges still exist in many aspects. For example, robust face recognition in outdoor-like environments is still difficult. As a result, the problem of face recognition remains attractive to many researchers across multiple disciplines, including image processing, pattern recognition and learning, computer vision, computer graphics, neuroscience, and psychology. Research efforts are ongoing to advance the state of the art in various aspects of face processing. For example, understanding of how humans can routinely perform robust face recognition can shed some light on how to improve machine recognition of human faces. Another example is that modeling 3D face geometry and reflectance properties can help design a robust system to handle illumination and pose variations.
To further advance this important field, we believe that continuous dialog among researchers is important. It is in this spirit that we decided to edit a book on the subject of advanced methods and modeling. Because this subject is experiencing very rapid developments, we choose the book format as a collection of chapters, written by experts. Consequently, readers will have the opportunity to read the most recent advances reported directly by experts from diverse backgrounds. For those who are new to this field, we have included three introductory chapters on the general state of the art, eigen approaches, and evaluation of face recognition systems. It is our hope that this book would engage readers at various levels and, more importantly, provoke debates among all of us in order to make a big leap in performance.