1. A method of processing bit mapped image data representing the intensity of each of a plurality of pixels forming an image of an area of an individual's retina including the optic disk to generate a signal pattern to verify the identity of the individual, comprising: finding a boundary of the optic disk in the image represented by said pixel data; generating a signal pattern representing the intensity of pixels having a predetermined relationship with respect to the boundary of the optic disk; and comparing the generated signal pattern to a stored signal pattern to verify the identity of the individual.