Iris biometric matching system

1. A computer system for biometric iris matching, comprising:

a processor;

memory coupled to the processor, the memory comprising instructions configured to cause the computer system to:

receive at least one input image of an eye;

generate one or more edge maps corresponding to each of the at least one input image;

segment a pupil area in each of the at least one input image;

segment an iris area from a sclera area in each of the at least one input image; and

synthesize an artificial pupil on the at least one input image within the segmented pupil area.

2. The biometric iris matching system of claim 1 , configured to construct one or more candidate pupil contours based on the one or more edge map.

3. The biometric iris matching system of claim 2 , wherein each edge map contains at least one candidate pupil contour.

4. The biometric iris matching system of claim 1 , configured to correct ones of the at least one input image for low-contrast boundaries.

5. The biometric iris matching system of claim 4 , configured to correct ones of the at least on einput image for iris boundaries.

6. The biometric iris matching system of claim 1 , configured to normalize iris diameters in ones of the at least one input image using a range estimate derived from an autofocus setting of a camera taking the at least one input image.

7. The biometric iris matching system of claim 1 , configured to produce one or more rectified iris images.

8. The biometric iris matching system of claim 7 , configured to transform the rectified iris images into transformed iris images.

9. The biometric iris matching system of claim 8 , wherein the transformed iris images are invariant coordinate system image representations of the rectified iris images.

10. The biometric iris matching system of claim 9 , configured to mask off specular reflections and unstable regions in the transformed iris images to produce masked converted iris images.

11. The biometric iris matching system of claim 10 , configured to subsample the masked transformed iris images into a plurality of filtered images that range from high frequency bands to low frequency bands.

12. A computer system for biometric iris matching, comprising:

a processor; and

memory comprising instructions configured to cause the computer system to:

receive at least one input image of an eye;

estimate an angle of tilt of the eye in the at least one input image with respect to a camera that captured the image; and

correct corneal distortion based on the estimated angle of tilt.

13. The iris biometric matching system of claim 12 , configured to correct corneal distortion by aligning an iris contour and a pupil contour of the eye into concentric circles.

14. The biometric iris matching system of claim 12 , configured to correct for perspective distortion based on the estimated angle of tilt.

15. The biometric iris matching system of claim 12 , wherein the estimate of the angle of tilt is based at least in part on a location of a reflection in the cornea of the eye in the at least one input image with respect to the camera orientation.

16. The biometric iris matching system of claim 12 , configured to stretch the input image in the estimated direction of tilt.

17. The biometric iris matching system of claim 12 , configured to apply an affine or projective transformation to the at least one input image.

18. A method for biometric iris matching, implemented on a computer system, the method comprising:

receiving at least one input image of an eye;

segmenting a pupil area in an eye detected in at least one input image;

selecting a pupil contour based on one or more of a best fitting circle and a best inscribed circle; and

segmenting an iris area from a sclera area in each of the one or more eyes in the input image.

19. The method for biometric iris matching of claim 18 , comprising:

constructing one or more candidate pupil contours based on one or more edge maps, wherein each edge map comprises at least one candidate pupil contour; and

determining a best matching candidate pupil contour for each eye in the input image.

20. The method for biometric iris matching of claim 19 , comprising generating one or more edge maps corresponding to each eye in the input image.