Patent ID: 7130453

Claim:
A method for detecting an eye position from a face image including at least an eye area, the face image being taken under near infrared light, comprising the steps of: performing brightness correction for part or the entire of the face image to increase the contrast between a sclera portion and an iris portion of the eye; calculating brightness gradient vectors for the brightness-corrected face image; and performing matching between a brightness gradient image generated using the calculated brightness gradient vectors and an eye template, wherein the eye position is detected based on the results of the matching, wherein the brightness correction step includes the steps of: calculating a brightness gradient for each pixel in a part of the face image for brightness correction; generating an expression for conversion for histogram equalization using some of pixels in the part, the some pixels being a top A percent of the pixels in the part ranked according to a brightness gradient intensity where A is a predetermined value; and performing histogram equalization for all pixels in the part using the generated expression for conversion.