Review of micro-expression spotting and recognition in video sequences

Abstract Facial micro-expressions are short and imperceptible expressions that involuntarily reveal the true emotions that a person may be attempting to suppress, hide, disguise, or conceal. Such expressions can reflect a person's real emotions and have a wide range of application in public safety and clinical diagnosis. The analysis of facial micro-expressions in video sequences through computer vision is still relatively recent. In this research, a comprehensive review on the topic of spotting and recognition used in microexpression analysis databases and methods, is conducted, and advanced technologies in this area are summarized. In addition, we discuss challenges that remain unresolved alongside future work to be completed in the field of micro-expression analysis.