Method of measuring the focus of close-up images of eyes

Details Method of measuring the focus of close-up images of eyes Method of measuring the focus of close-up images of eyes

1997-12-02

1999-09-14

Boudreau, Leo H.

Image analysis

Applications

Personnel identification

382199, 382255, G06K 900, G06K 948, G06K 940

Patent

active

059534400

ABSTRACT:
In a method of determining whether an image of an eye is in focus a set of pixels is selected along a line passing through the pupil/iris boundary such that the set contains at least 5 iris portion pixels and at least 5 pupil portion pixels. Statistical values, preferably median values, are computed for all iris pixels in the selected set and for all pupil pixels in the selected set. The step size between the iris pixels and the pupil pixels is computed and absolute gradient values are computed for each pixel. The pixel having a largest absolute gradient value is excluded and an average of the absolute gradient values of the remaining pixels is found. If that average divided by the step size is greater than 0.5 the image is in focus and can be used for identifying a subject whose eye is in the image using iris identification techniques.

REFERENCES:
patent: 5534923 (1996-07-01), Suda
patent: 5621822 (1997-04-01), Yukawa et al.
patent: 5659812 (1997-08-01), Uchiyama
patent: 5678097 (1997-10-01), Suda

Affiliated with

Also associated with

Rating

Method of measuring the focus of close-up images of eyes does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of measuring the focus of close-up images of eyes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of measuring the focus of close-up images of eyes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1518020