Approaches and apparatus for eye detection in a digital image

• US 8,090,157 B2
• Filed: 02/07/2007
• Issued: 01/03/2012
• Est. Priority Date: 01/26/2005
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Honeywell International Inc.
• Inventors: Ahrens, Terry, Hamza, Rida M.
• Primary Examiner(s): Le, Brian Q
• Application Number:
  US11/672,108
• Publication Number:
  US 20070189582A1
• Time in Patent Office: 1,791 Days
• Field of Search: 382/115, 382/117, 348/78, 396/18, 396/51
• US Class Current: 382/115
• CPC Class Codes: G06V 40/171 Local features and components; Facial parts eye characteristics G06V40/18; Occluding parts, e.g. glasses; Geometrical relationships
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction

Abstract

A system for finding and providing images of eyes acceptable for review, recordation, analysis, segmentation, mapping, normalization, feature extraction, encoding, storage, enrollment, indexing, matching, and/or the like. The system may acquire images of the candidates run them through a contrast filter. The images may be ranked and a number of candidates may be extracted for a list from where a candidate may be selected. Metrics of the eyes may be measured and their profiles evaluated. Also, the spacing between a pair of eyes may be evaluated to confirm the pair'"'"'s validity. Eye images that do not measure up to certain standards may be discarded and new ones may be selected.

Claims

1. A computer implemented eye detection system for detecting eyes in a digital image, the system comprising:

a digital image capture device; and

a processor, the processor including;

a filter;

a first eye candidate selector connected to the filter;

a first profile validator connected to the eye candidate selector, the first profile validator including measurements of eye candidate pupil contours;

a first eye candidate eliminator connected to the first profile validator and the first eye candidate selector;

a second eye candidate selector connected to the first profile validator;

a pair validator connected to the second eye candidate selector, the pair validator including a space measurer that determines if the first and second eye candidates are at an appropriate distance from each other;

a second profile validator connected to the pair validator; and

a second eye candidate eliminator connected to the second profile validator and the second eye candidate selector;

wherein the first profile validator comprising a first profiler connected to the first eye candidate selector, and a first profile evaluator connected to the first profiler, the first eye candidate eliminator and the second eye candidate selector;

wherein the second profile validator comprises a second profiler connected to the pair validator, and a second profile evaluator connected to the second profiler and the second eye candidate eliminator;

wherein the first profiler comprises;

a pupil region extractor connected to the first eye candidate selector;

an adaptive thresholder connected to the pupil region extractor;

a contours finder connected to the adaptive thresholder;

a contour picker connected to the contours finder;

a curve fitter connected to the contour picker; and

a curve selector connected to the curve fitter and the first profile evaluator; and

wherein the second profiler comprises;

a pupil region extractor connected to the pair validator;

an adaptive thresholder connected to the pupil region extractor;

a contours finder connected to the adaptive thresholder;

a contour picker connected to the contours finder;

a curve fitter connected to the contour picker; and

a curve selector connected to the curve fitter and the second profile evaluator.

2. The system of claim 1, further comprising:

a resulter connected to the first and second profile validators; and

a stopper connected to the first and second eye candidate eliminators.

3. The system of claim 1, wherein:

the first eye candidate selector comprises;

a ranking mechanism connected to the filter;

an eye candidates extractor connected to the ranking mechanism; and

a first eye candidate determiner connected to the eye candidate extractor, a first profiler and the first eye candidate eliminator; and

the second eye candidate selector comprises;

the ranking mechanism connected to the filter;

the eye candidates extractor connected to the ranking mechanism; and

a second eye candidate determiner connected to the first profile evaluator, the pair validator and the second eye candidate eliminator.

7. The system of claim 1, wherein an adaptive threshold is computed adaptively based upon a pupil size and a contrast distribution of an image region having a pupil and its surrounding area.

8. The system of claim 1, wherein the pair validator comprises:

a range indicator connected to the space measurer and the second profile validator.

9. The system of claim 1, further comprising:

a resulter connected to the first and second profile validators; and

wherein the resulter is for receiving a valid pair of eye candidates.

10. The system of claim 1, wherein:

the filter is a contrast filter.

11. The system of claim 10, wherein the contrast filter is based upon a pupil dark profile with respect to its surroundings.

12. The system of claim 10, wherein the contrast filter is based upon a light reflection profile with respect to its surroundings.

4. A computer implemented method for finding an eye in a digital image, comprising:

providing a digital image capture device and a processor;

obtaining a digital image containing eye candidates from the digital image capture device; and

processing the digital image to find an eye with the processor, the processing including;

contrast filtering the eye candidates;

selecting a first eye from the eye candidates;

validating a profile of the first eye;

selecting a second eye from the eye candidates;

validating an amount of space between the first and second eyes;

validating a profile of the second eye, wherein validating the profile of the first and second eyes includes measuring pupil contours;

eliminating the first eye if the first eye has an invalid profile;

eliminating the second eye if the amount of space between the first and second eyes is invalid; and

eliminating the second eye if the amount of space between the first and second eyes is valid and the second eye has an invalid profile.

5. A computer implemented eye detection system for detecting eyes having pupils in a digital image, the system comprising:

a digital image capture device; and

a processor, the processor including;

a filter;

a first eye candidate selector connected to the filter;

a first profile validator connected to the eye candidate selector, the profile validator including measurements of pupil contours;

a first eye candidate eliminator connected to the first profile validator and the first eye candidate selector;

a second eye candidate selector connected to the first profile validator;

a pair validator connected to the second eye candidate selector, the pair validator including a space measurer that determines if the first and second eye candidates are at an appropriate distance from each other;

a second profile validator connected to the pair validator; and

a second eye candidate eliminator connected to the second profile validator and the second eye candidate selector;

wherein the first profile validator comprises;

a first profiler connected to the first eye candidate selector; and

a first profile evaluator connected to the first profiler, the first eye candidate eliminator and the second eye candidate selector; and

wherein the second profile validator comprises;

a second profiler connected to the pair validator; and

a second profile evaluator connected to the second profiler and the second eye candidate eliminator;

wherein the first profiler comprises;

a pupil region extractor connected to the first eye candidate selector;

an adaptive thresholder connected to the pupil region extractor;

a contours finder connected to the adaptive thresholder;

a contour picker connected to the contours finder;

a curve fitter connected to the contour picker; and

a curve selector connected to the curve fitter and the first profile evaluator; and

wherein the second profiler comprises;

a pupil region extractor connected to the pair validator;

an adaptive thresholder connected to the pupil region extractor;

a contours finder connected to the adaptive thresholder;

a contour picker connected to the contours finder;

a curve fitter connected to the contour picker; and

a curve selector connected to the curve fitter and the second profile evaluator.

6. An eye finder system for finding eyes in a digital image comprising:

a camera;

a filter connected to the camera;

an eye candidate lister connected to the filter;

an eye selector connected to the eye candidate lister;

an eye profile evaluator connected to the eye selector; and

an eye eliminator connected to the eye profile evaluator;

wherein the eye eliminator comprises;

a deleter, connected to the eye profile evaluator, for removing the eye from a list provided by the eye candidate lister if the eye profile evaluator indicates a profile of the eye to be invalid; and

a counter connected to the deleter and to the eye selector;

if the counter has a count greater than zero, then the eye selector may select a new eye from the list provided by the eye candidate lister;

or

if the counter has a count not greater than zero, then the system may stop.

13. A computer implemented method for finding an eye in a digital image, comprising:

providing a digital image capture device and a processor;

obtaining a digital image containing eye candidates from the digital image capture device; and

processing the digital image to find an eye with the processor, the processing including;

contrast filtering the eye candidates;

selecting a first eye from the eye candidates;

validating a profile of the first eye;

selecting a second eye from the eye candidates;

validating an amount of space between the first and second eyes;

validating a profile of the second eye, wherein validating the profile of the first and second eyes includes measuring pupil contours;

eliminating the first eye if the first eye has an invalid profile;

eliminating the second eye if the amount of space between the first and second eyes is invalid; and

eliminating the second eye if the amount of space between the first and second eyes is valid and the second eye has an invalid profile.

14. The method of claim 13, wherein:

the selecting a first eye comprises;

prioritizing the eye candidates according to contrast into a first list of eye candidates;

extracting a number of eye candidates from the first list of eye candidates into a second list of eye candidates; and

selecting a first eye from the second list of eye candidates; and

the selecting a second eye comprises selecting a second eye from the second list of eye candidates.

15. The method of claim 14, wherein:

the validating a profile of first eye comprises;

measuring profile metrics of the first eye; and

determining whether the profile metrics of the first eye are valid; and

the validating a profile of second eye comprises;

measuring profile metrics of the second eye; and

determining whether the profile metrics of the second eye are valid.

16. The method of claim 15, wherein the validating an amount of space between the first and second eyes comprises:

measuring a spacing between the first and second eyes; and

determining whether the spacing is within a valid range.

17. An eye finder system for finding eyes in a digital image comprising:

a camera;

a filter connected to the camera;

an eye candidate lister connected to the filter;

an eye selector connected to the eye candidate lister;

an eye profile evaluator connected to the eye selector, the eye profile evaluator measuring pupil image and pupil contours, and including a pair validator, the pair validator including a space measurer that determines if the first and second eye candidates are at an appropriate distance from each other; and

an eye eliminator connected to the eye profile evaluator, the eye eliminator comprising;

a deleter, connected to the eye profile evaluator, for removing the eye from a list provided by the eye candidate lister if the eye profile evaluator indicates a profile of the eye to be invalid; and

a counter connected to the deleter and to the eye selector;

wherein if the counter has a count greater than zero, then the eye selector may select a new eye from the list provided by the eye candidate lister;

or

if the counter has a count not greater than zero, then the system may stop.

18. The system of claim 17, further comprising:

a second eye selector connected to the eye profile evaluator;

an eye pair evaluator connected to the second eye selector; and

a second profile evaluator connected to the eye pair evaluator.

19. The system of claim 18, wherein if the profile evaluator and the second profile evaluator indicate that a first eye and a second eye have appropriate metrics, and the eye pair evaluator determines that the first eye and second eye are appropriately spaced from each other, then the first and second eyes or portions of them are acceptable for review, recordation, analysis, segmentation, mapping, normalization, feature extraction, encoding, storage, enrollment, indexing, matching, and/or the like.

20. The system of claim 18, wherein if just one eye is indicated by one or more profile evaluators to have appropriate metrics, then the eye or a portion of it is acceptable for review, recordation, analysis, segmentation, mapping, normalization, feature extraction, encoding, storage, enrollment, indexing, matching, and/or the like.

21. The system of claim 17, wherein the eye profile evaluator comprises:

a pupil region extractor connected to the eye selector;

an adaptive thresholder connected to the pupil region extractor;

a contours finder connected to the adaptive thresholder;

a contour picker connected to the contours finder;

a curve fitter connected to the contour picker; and

a best curve selector connected to the curve fitter.