Adaptive iris matching using database indexing

1. A standoff iris recognition system comprising:

an iris image acquisition module;

an image quality evaluator connected to the iris image acquisition module; and

an adaptive iris matching module connected to the image quality evaluator and the eye image acquisition module; and

wherein the image quality evaluator determines if an eye image from the iris image acquisition module has a quality which is too low for a non-adaptive iris matching module and is sufficiently high enough for the adaptive iris matching module; and

wherein if the quality is high enough for the adaptive iris matching module, the adaptive iris matching module executes a search and generates a list of possible matches without segmenting a circumferential of an iris of the eye image.

2. The system of claim 1 , wherein the non-adaptive iris matching module processes an iris image having sufficient quality so that a best match for the iris image can be generated from a database of iris images.

3. The system of claim 2 , wherein the adaptive iris matching module processes an iris image having low but sufficient quality so that a group of most probable matches for the iris image instead of one best match can be generated from a database of iris images.

4. The system of claim 3 , wherein the image quality evaluator determines whether an iris image has sufficient quality for successful processing by the non-adaptive iris matching module or not sufficient quality for successful processing by the non-adaptive iris matching module but has sufficient quality for processing by the adaptive iris matching module, or not sufficient quality for processing by the non-adaptive iris matching module or by the adaptive iris matching module.

5. The system of claim 4 , wherein:

if an iris image has not sufficient quality for processing by the non-adaptive iris matching module or by the adaptive iris matching module, then the image is rehabilitated, if possible, for processing by the non-adaptive iris matching module or by the adaptive iris matching module; and

if the iris image cannot be rehabilitated, then the iris image is rejected.

6. The system of claim 1 , wherein the image quality evaluator determines a quality of an iris image relative to blur, obscuration, standoff angle, and/or iris visibility of the iris image.

7. The system of claim 1 , wherein the adaptive iris matching module is for segmenting a visible portion of an iris image, partial encoding, database indexing, and/or adaptive matching relative to the visible portion of the iris image.

8. The system of claim 7 , wherein the adaptive iris matching module is further for normalizing data points of an iris portion along a visible radial at an angle segment of an iris image.

9. The system of claim 7 , wherein the adaptive iris matching module is further for encoding a partial visible iris map signature of an iris image.

10. The system of claim 7 , wherein the database indexing comprises:

providing a database having templates; and

grouping the database into a plurality of sub-databases; and

wherein:

each template in the database has a first number of bits based on angular indexing;

each sub-database of the plurality of sub-databases represents virtually all templates in the database; and/or

each template in a sub-database has a second number of bits based on a hierarchical structure.

11. The system of claim 10 , wherein the database indexing further comprises:

providing a subset of template barcodes for possible matching; and/or

selecting a second number of bits of a barcode that corresponds to the second number of bits of each template.

12. The system of claim 11 , wherein the adaptive iris matching module is further for normalizing a number of data points from an obscured iris portion of an iris image to match one of the templates.

13. The system of claim 12 , wherein the adaptive iris matching module is further for encoding a partial obscured iris map signature.

14. The system of claim 13 , wherein the adaptive iris matching module is further for comparing iris barcodes to a previously generated reference iris signature.

15. A method for standoff iris recognition, comprising:

segmenting a visible region of an iris, with a model providing a first order estimate of a border segment;

extracting associated partial codes of a barcode of the iris to index a smaller population of a whole population; and

recovering noisy information in an obscured area by adapting a fitting model that provides best matching bits within the visible region of the iris;

wherein:

iris dyadic variations are captured by formulating a dynamic encoder that takes into account varying edge points; and

an encoding scheme is modified to make use of a dynamic wavelet function wherein a wavelength scalar of the wavelet function varies as a function of an angular variable.

16. The method of claim 15 , wherein:

the dynamic wavelet function is a smooth continuous function of the angular variable; and

an output of the dynamic wavelet function is enabled at each angle using virtually all possible values for a best match.

17. The method of claim 16 , wherein concatenated matched bits can determine an overall match score between a probe and a query barcode.

18. A method for adaptive iris matching, comprising:

acquiring an image of an iris;

evaluating quality of the image;

processing a visible region of the iris in the image on a radial direction without segmenting a circumferential of the iris in the image, if the quality is too low for non-adaptive iris matching but high enough for adaptive iris matching;

estimating a boundary for the visible region of the iris in the image;

constructing an iris map using a rubber sheet model;

masking a non-visible region of the iris;

encoding the iris map for at least partial comparisons between templates;

extracting associated partial codes of an iris code to index a portion of a database; and

retrieving a list of two or more possible iris matches from the database with the iris code as a query.