IRIS EXTRACTION METHOD CAPABLE OF PRECISELY DETERMINING POSITIONS AND SIZES OF IRISES INA DIGITAL FACE IMAGE

The present invention relates to an iris extraction method. In the method, two searching regions are defined in a face image. A deformable template match algorithm and an energy function are used to measure the energy of each pixel with different hypothetical circular templates within the searching region. Pixels with the same hypothetical radius having energies greater than a predetermined threshold are recorded as iris candidates, wherein the pixel having the maximal energy is recorded as first iris candidate. Further, it detects associated iris pairs from iris candidates in each searching region, records the lower iris candidate having the maximal energy of iris pairs as second iris candidate, and selects the best iris candidate from first iris candidate and second iris candidate. Finally, it designates the best iris candidate having the maximal energy of all best iris candidates with different hypothetical radius as the iris in the face image.