Human–computer interaction (HCI) is one of the most significant areas of computational intelligence. This book focuses on the human emotion analysis aspects of HCI, highlighting innovative methodologies for emotion analysis by machines/computers and their application areas. The methodologies are presented with numerical results to enable researchers to replicate the work. This multidisciplinary book is useful to researchers and academicians, as well as students wanting to pursue a career in computational intelligence. It can also be used as a handbook, reference book, and a textbook for short courses.