Automatic pupil size measurement based on region growth

Dynamic pupillometry, a method that consists of measuring changes in pupil size in response to a light stimulus, can provide information about the autonomous nervous system. Therefore, it is used in the assessment of some diseases, such as diabetes. In biometric systems, it has also been used as aliveness test and, more recently to extract features to identify subjects by dynamic characteristics. This paper presents some automatic methods that can be used for this purpose and proposes a new approach, based on region grow, comparing the results of each one.