Iris identification system and method, and storage media having program thereof

• US 20050008201A1
• Filed: 12/03/2002
• Published: 01/13/2005
• Est. Priority Date: 12/03/2001
• Status: Abandoned Application

• Current Assignee: Reburns Co., Ltd., Yill-Byung Lee
• Original Assignee: Reburns Co., Ltd., Yill-Byung Lee
• Inventors: Yoon, Sung-Soo, Lee, Kwan-Young, Kee, Kyung-Do, Lee, Yill-Byung
• Application Number:
  US10/495,960
• Publication Number:
  US 20050008201A1
• Time in Patent Office: Days
• US Class Current: 382/117
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris

Abstract

Disclosed is an iris identification system and method, and storage media having program thereof. The iris identification system comprising a characteristic vector database (DB) for pre-storing characteristic vectors to identify persons; an iris image extractor for extracting an iris image in the eye image inputted from the outside; a characteristic vector extractor for multi-dividing the iris image extracted by the iris image extractor, obtaining a iris characteristic region from the multi-divided each iris image, and extracting a characteristic vector from the iris characteristic region by a statistical method; and a recognizer for comparing the characteristic vector DB thereby identifying a person.

Claims

1. An iris identification system comprising:

a characteristic vector database (DB) for pre-storing characteristic vectors to identify persons;

an iris image extractor for extracting an iris image in the eye image inputted from the outside;

a characteristic vector extractor for multi-dividing the iris image extracted by the iris image extractor, obtaining a iris characteristic region from the multi-divided each iris image, and extracting a characteristic vector from the iris characteristic region by a statistical method; and

a recognizer for comparing the characteristic vector extracted from the characteristic vector extractor with the characteristic vector stored in the characteristic vector DB thereby identifying a person.

2. The iris identification system as claimed in claim 1, wherein the iris image extractor comprises:

an edge element detecting section for detecting edge element by applying Canny edge detection method to the eye image;

a grouping section for grouping the detected edge element;

an iris image extracting section for extracting the iris image by applying Bisection method to the grouped edge element; and

a normalizing section for normalizing the extracted iris image by applying elastic body model to the extracted iris image.

3. The iris identification system as claimed in claim 2, wherein the elastic body model comprises a plurality of elastic bodies, each elastic body is extendible in a longitudinal direction, and has one end connected to sclera and the other end connected to pupil.

4. The iris identification system as claimed in claim 1, wherein the characteristic vector extractor comprises:

a multi-dividing section for wavelet-packet transforming the iris image extracted by the iris image extractor to multi-divide the extracted iris image;

a calculating section for calculating energy values for regions of the multi-divided iris images;

a characteristic region extracting section for extracting and storing the region that has energy value more than a predetermined reference value from the regions of the multi-divided iris images; and

a characteristic vector constructing section for dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value;

for the region extracted from the characteristic region extracting section, the wavelet-packet transform process by the multi-dividing section and the energy value calculating process by the calculating section are repeatedly executed in a determined number, and then the regions having energy value more than the reference value are stored in the characteristic region extracting section.

5. The iris identification system as claimed in claim 4, wherein the calculating section squares the each energy value of the multi-divided region, adds the squared energy values, and divides the added energy value by number of the region thereby capable of obtaining the resultant energy value.

6. The iris identification system as claimed in claim 4, wherein the recognizer calculates the distance between characteristic vectors by applying Support vector machine method to the characteristic vector extracted from the characteristic vector extracting section and the characteristic vector pre-stored in the characteristic vector DB, and confirm the identity for a person if the calculated distance between the characteristic vectors is smaller than the predetermined reference value.

7. The iris identification system as claimed in claim 1, wherein the characteristic vector extractor comprises:

a multi-dividing section for multi-dividing the iris image extracted from the iris image extractor by applying Daubechies wavelet transform to the extracted iris image, and extracting the region including the high frequency component HH for x-axis and y-axis from the multi-divided iris image;

a calculating section for calculating discrimination rate D of the iris pattern by the characteristic value of the HH region, and increments repeat number;

a characteristic region extracting section for determining whether the predetermined reference value is smaller than the discrimination rate D or the repeat number is smaller than the predetermined reference number, completing operation thereof if the reference value is larger than the discrimination rate D or the repeat number is larger than the reference number, storing and administrating the information of HH region if the reference value is equal to or smaller than the discrimination rate D, or the repeat number is equal to or smaller than the reference number, extracting the region LL that has low frequency component for the x-axis and y-axis, selecting the LL region as a new process object image; and

a characteristic vector constructing section for dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value;

for the region selected as the new process object image by the characteristic region extracting section, the multi-dividing process by the multi-dividing section and the processes thereafter are repeatedly executed.

8. The iris identification system as claimed in claim 7, wherein the discrimination rate D is the value obtained by squaring value of the each pixel of HH region, adding the squared values, and dividing the added value by total number of the HH region.

9. The iris identification system as claimed in claim 7, wherein the recognizer confirms the identity for a person by applying the normalized Euclidian distance and Minimum distance classification rule to the characteristic vector extracted from the characteristic vector extractor and the characteristic vector pre-stored in the characteristic vector DB.

10. The iris identification system as claimed in claim 1, wherein the system further comprises a filter for filtering the eye image inputted from the outside, and outputting it to the iris image extractor.

11. The iris identification system as claimed in claim 10, wherein the filter comprises:

a blinking detecting section for detecting a blinking of the eye image;

a pupil position detecting section for the position of the pupil in the eye image;

a vertical component detecting section for detecting the vertical component of the edge;

a filtering section for excluding the eye images that the values obtained by multiplying values detected respectively by the blinking detecting section, the pupil position detector and the vertical component detector by the weighed values W1, W2, and W3 respectively is more than a predetermined reference value, and outputting the remaining eye image to the iris image extractor.

12. The iris identification system as claimed in claim 11, wherein when the eye image is divided into M×

N blocks, the blinking detecting means calculates sum of average brightness of blocks in a raw, and outputs the brightest value F1.

13. The iris identification system as claimed in claim 12, wherein the weighted value W1 is weighted in proportion to the distance from the vertical center of the eye image.

14. The iris identification system as claimed in claim 11, wherein when the eye image is divided into M×

N blocks, the pupil position detecting section detects the block F2 that the average brightness of each block is smaller than the predetermined value.

15. The iris identification system as claimed in claim 14, wherein the weighted value W2 is weighted in proportional to the distance from the center of the eye image.

16. The iris identification system as claimed in claim 11, wherein the vertical component detecting section detects the value F3 of the vertical component of the iris region by Sobel edge detection method.

17. The iris identification system as claimed in claim 6, wherein the weighted value W3 is the same regardless of the distance from the center of the eye image.

18. The iris identification system as claimed in claim 1, the system further comprises a register to record the characteristic-vector extracted from the characteristic vector extractor in the characteristic vector DB.

19. The iris identification system as claimed in claim 1, the system further comprises a photographing means to take an eye image of a person and to output it to the filter.

34. The method as claimed in claim 14, wherein the weighted value W2 is weighted in proportional to the distance from the center of the eye image.

20. An iris identification method comprising the steps of:

extracting an iris image in the eye image inputted from the outside;

multi-dividing the extracted iris image, obtaining a iris characteristic region from the multi-divided each iris image, and extracting a characteristic vector from the iris characteristic region by a statistical method; and

comparing the extracted characteristic vector with the characteristic vector stored in the characteristic vector DB thereby identifying a person.

21. The method as claimed in claim 20, wherein the step of extracting the iris image comprises the sub-steps of:

(a1) detecting edge element by applying Canny edge detection method to the eye image;

(a2) grouping the detected edge element;

(a3) extracting the iris image by applying Bisection method to the grouped edge element; and

(a4) normalizing the extracted iris image by applying elastic body model to the extracted iris image.

22. The method as claimed in claim 21, wherein the elastic body model comprises a plurality of elastic bodies, each elastic body is extendible in a longitudinal direction, and has one end connected to sclera and the other end connected to pupil.

23. The method as claimed in claim 20, wherein the step of extracting the characteristic vector comprises the sub-steps of:

(b1) wavelet-packet transforming the iris image extracted by the step (a) to multi-divide the extracted iris image;

(b2) calculating energy values for regions of the multi-divided iris images;

(b3) extracting and storing the region that has energy value more than a predetermined reference value from the regions of the multi-divided iris images, and the wavelet-packet transform step to the energy value calculating step are repeatedly executed for the extracted region; and

(b4) dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value.

24. The method as claimed in claim 23, wherein the energy value is the value obtained by squaring energy values of the multi-divided region, adds the squared energy values, and divides the added energy value by total number of the region.

25. The method as claimed in claim 23, wherein the step of identifying a person comprises the steps of calculating the distance between characteristic vectors by applying Support vector machine method to the extracted characteristic vector and the pre-stored characteristic vector, and confirming the identity for a person if the calculated distance between the characteristic vectors is smaller than the predetermined reference value.

26. The method as claimed in claim 20, wherein the step of extracting the characteristic vector comprises the sub-steps of:

(b1) multi-dividing the iris image extracted from the iris image extractor by applying Daubechies wavelet transform to the extracted iris image;

(b2) extracting the HH region including the high frequency component for x-axis and y-axis from the multi-divided iris image;

(b3) calculating discrimination rate D of the iris pattern by the characteristic value of the HH region, and incrementing repeat number;

(b4) determining whether the predetermined reference value is smaller than the discrimination rate D or the repeat number is smaller than the predetermined reference number;

(b5) completing operation thereof if the reference value is larger than the discrimination rate D or the repeat number is larger than the reference number, and storing and administrating the information of HH region if the reference value is equal to or smaller than the discrimination rate D, or the repeat number is equal to or smaller than the reference number;

(b6) extracting the LL region including low frequency component for the x-axis and y-axis;

(b7) selecting the LL region as a new process object image wherein the multi-dividing step and the steps thereafter are repeatedly executed for the region selected as the new process object image; and

(b8) dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value.

27. The method as claimed in claim 26, wherein the discrimination rate D is the value obtained by squaring value of the each pixel of HH region, adding the squared values, and dividing the added value by total number of the HH region.

28. The method as claimed in claim 26, wherein the step of identifying a person comprises the step of confirming the identity for a person by applying the normalized Euclidian distance and Minimum distance classification rule to the extracted characteristic vector and the pre-stored characteristic vector.

29. The method as claimed in claim 20, further comprises the step of filtering the eye image inputted from the outside.

30. The method as claimed in claim 29, wherein the filtering step comprises the sub-steps of:

(c1) detecting a blinking of the eye image;

(c2) detecting the position of the pupil in the eye image;

(c3) detecting the vertical component of the edge;

(c4) excluding the eye images that the values obtained by multiplying values detected respectively by the blinking detecting, the pupil position detecting and the vertical component detecting steps by the weighed values W1, W2, and W3 respectively is more than a predetermined reference value, and using the remaining eye image.

31. The method as claimed in claim 30, wherein the step (c1) comprises the sub-steps of, when the eye image is divided into M×

N blocks, calculating sum of average brightness of blocks in each raw, and outputting the brightest value F1.

32. The method as claimed in claim 31, wherein the weighted value W1 is weighted in proportion to the distance from the vertical center of the eye image.

33. The method as claimed in claim 30, wherein the step (c2) comprises the sub-step of, when the eye image is divided into M×

N blocks, detecting the block F2 that the average brightness of each block is smaller than the predetermined value.

35. The method as claimed in claim 30, wherein the step (c3) detects the value F3 of the vertical component of the iris region by Sobel edge detection method.

36. The method as claimed in claim 35, wherein the weighted value W3 is the same regardless of the distance from the center of the eye image.

37. The method as claimed in claim 20, the method further comprises the step of recording the extracted characteristic vector.

38. A computer-readable storage medium on which a program is stored, the program including the processes of:

extracting an iris image in the eye image inputted from the outside;

multi-dividing the extracted iris image, obtaining a iris characteristic region from the multi-divided each iris image, and extracting a characteristic vector from the iris characteristic region by a statistical method; and

comparing the extracted characteristic vector with the characteristic vector stored in the characteristic vector DB thereby identifying a person.

39. The storage medium as claimed in claim 38, wherein the process of extracting the iris image comprises the sub-processes of:

(a1) detecting edge element by applying Canny edge detection method to the eye image;

(a2) grouping the detected edge element;

(a3) extracting the iris image by applying Bisection method to the grouped edge element; and

(a4) normalizing the extracted iris image by applying elastic body model to the extracted iris image.

40. The storage medium as claimed in claim 39, wherein the elastic body model comprises a plurality of elastic bodies, each elastic body is extendible in a longitudinal direction, and has one end connected to sclera and the other end connected to pupil.

41. The storage medium as claimed in claim 38, wherein the process of the characteristic vector comprises the sub-processes of:

(b1) wavelet-packet transforming the iris image extracted by the process of extracting the iris image to multi-divide the extracted iris image;

(b2) calculating energy values for regions of the multi-divided iris images;

(b3) extracting and storing the region that has energy value more than a predetermined reference value from the regions of the multi-divided iris images, and the wavelet-packet transform process to the energy value calculating process are repeatedly executed for the extracted region; and

(b4) dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value.

42. The storage medium as claimed in claim 41, wherein the energy value is the value obtained by squaring energy values of the multi-divided region, adds the squared energy values, and divides the added energy value by total number of the region.

43. The storage medium as claimed in claim 41, wherein the process of identifying a person comprises the sub-processes of calculating the distance between characteristic vectors by applying Support vector machine method to the extracted characteristic vector and the pre-stored characteristic vector, and confirming the identity for a person if the calculated distance between the characteristic vectors is smaller than the predetermined reference value.

44. The storage medium as claimed in claim 38, wherein the process of extracting the characteristic vector comprises the sub-processes of:

(b1) multi-dividing the iris image extracted from the iris image extractor by applying Daubechies wavelet transform to the extracted iris image;

(b2) extracting the HH region including the high frequency component for x-axis and y-axis from the multi-divided iris image;

(b3) calculating discrimination rate D of the iris pattern by the characteristic value of the HH region, and incrementing repeat number;

(b4) determining whether the predetermined reference value is smaller than the discrimination rate D or the repeat number is smaller than the predetermined reference number;

(b5) completing operation thereof if the reference value is larger than the discrimination rate D or the repeat number is larger than the reference number, and storing and administrating the information of HH region if the reference value is equal to or smaller than the discrimination rate D, or the repeat number is equal to or smaller than the reference number;

(b6) extracting the LL region including low frequency component for the x-axis and y-axis;

(b7) selecting the LL region as a new process object image wherein the multi-dividing process and the processes thereafter are repeatedly executed for the region selected as the new process object image; and

(b8) dividing the extracted and stored region into sub-regions, obtaining average value and standard deviation value for the sub-regions, and constructing a characteristic vector by using the average value and the standard deviation value.

45. The storage medium as claimed in claim 44, wherein the discrimination rate D is the value obtained by squaring value of the each pixel of HH region, adding the squared values, and dividing the added value by total number of the HH region.

46. The storage medium as claimed in claim 44, wherein the process of identifying a person comprises the process of confirming the identity for a person by applying the normalized Euclidian distance and Minimum distance classification rule to the extracted characteristic vector and the pre-stored characteristic vector.

47. The storage medium as claimed in claim 38, further comprises the process of filtering the eye image inputted from the outside.

48. The storage medium as claimed in claim 47, wherein the filtering process comprises the sub-processes of:

(c1) detecting a blinking of the eye image;

(c2) detecting the position of the pupil in the eye image;

(c3) detecting the vertical component of the edge;

(c4) excluding the eye images that the values obtained by multiplying values detected respectively by the blinking detecting process, the pupil position detecting process and the vertical component detecting process by the weighed values W1, W2, and W3 respectively is more than a predetermined reference value, and using the remaining eye image.

49. The storage medium as claimed in claim 48, wherein the process (c1) comprises the sub-processes of, when the eye image is divided into M×

N blocks, calculating sum of average brightness of blocks in each raw, and outputting the brightest value F1.

50. The storage medium as claimed in claim 49, wherein the weighted value W1 is weighted in proportion to the distance from the vertical center of the eye image.

53. The storage medium as claimed in claim 48, wherein the process (c3) detects the value F3 of the vertical component of the iris region by Sobel edge detection method.

54. The storage medium as claimed in claim 53, wherein the weighted value W3 is the same regardless of the distance from the center of the eye image.

55. The storage medium as claimed in claim 38, the program further comprises the process of recording the extracted characteristic vector.

51. The storage medium as claimed in claim 51, wherein the process (c2) comprises the sub-process of, when the eye image is divided into M×

N blocks, detecting the block F2 that the average brightness of each block is smaller than the predetermined value.

52. The storage medium as claimed in claim 51, wherein the weighted value W2 is weighted in proportional to the distance from the center of the eye image.