1. A mobile device image authentication system, comprising: a mobile device camera for capturing a current image of a subject in ambient visible light; a data storage device in the mobile device storing at least one of an image of the subject and data created from an image of the subject that includes features of the subject discernable in visible light; a processor in the mobile device coupled to the data storage device and the camera, the processor including instructions which, when executed by the processor, cause the processor to: receive the current image from the camera; convert the current image received from the camera to greyscale if the current image is in color; detect the eyes of the subject in the current image; move the face of the subject in the current image to fix at least one of the left eye and the right eye in a predetermined position in a current image field; scale the face in the current image to a standard size based on the location of the eye that has not been fixed in the current image; equalize lighting on a left side of the face and a right side of the face; binarize the current image; identify features of the face; remove segments having fewer than a predetermined number of contiguous pixels from the features of the face; mask the current image to remove segments around the face; compare the current image to one of the one or more stored images; and determine whether the current image and the one of the one or more stored images are of the same person.