Iris identification system and method of identifying a person through iris recognition

• US 6,247,813 B1
• Filed: 11/04/1999
• Issued: 06/19/2001
• Est. Priority Date: 04/09/1999
• Status: Expired due to Term

• Current Assignee: Iritech Incorporated
• Original Assignee: Iritech Incorporated
• Inventors: Ryoo, Jang Soo, Kim, Dae Hoon
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US09/433,254
• Time in Patent Office: 593 Days
• Field of Search: 351/200, 351/205, 351/206, 351/221, 382/115, 382/117, 382/182, 382/181, 235/379, 235/380, 235/382, 235/438, 340/825.31, 902/5
• US Class Current: 351/206
• CPC Class Codes: G06V 40/18 Eye characteristics, e.g. of the iris

Abstract

An iris identification system and method of identifying the identity of an animate being through iris scanning are disclosed. The system features an iris system pick-up unit including a camera for capturing iris images to create input image signals. The iris image pick-up unit is operated with a control unit that is interfaced with a data processing unit for preprocessing the input image signals into processed data. The processed data is representative of one of a plurality of parameters for iris identification selected from the group consisting of (1) the density and texture form of the iris fiber structure using a frequency transformation method, (2) pupilliary reaction, (3) the shape of the pupil, (4) autonomous nervous wreath reaction, (5) shape of the autonomous nervous wreath, (6) the existence of lacuna, (7) the location of the lacuna, and (8) the shape of the lacuna. The control unit is operable to compare processed data with parameters pre-stored in a data base that correspond to the processed data parameters to determine a match indicative of a confirmation of identity.

Claims

1. A system for confirming the identity of an animate being through iris scanning, comprising:

a) a control unit for receiving identifier information identifying the animate being, and a data storage unit including a data base accessed by the control unit for containing predetermined personal information associated with an identifiable being for comparison with identifier information;

b) an iris image pick-up unit including a camera operated by the control unit when the identifier information corresponds to the predetermined information for capturing iris images to create input image signals; and

c) a data processing unit for preprocessing the input image signals into processed data;

wherein said storage unit includes, for the identifiable being, at least one of a plurality of pre-stored parameters for iris identification selected from the group consisting of (1) the density and texture from of the iris fiber structure using a frequency transformation method, (2) pupillary reaction, (3) the shape of the pupil, (4) autonomous nervous wreath reaction, (5) shape of the autonomous nervous wreath, (6) the existence of lacuna, (7) the location of the lacuna, and (8) the shape of the lacuna, said control unit being operable to compare the processed data with said parameter(s) to determine if there is a match indicative of a confirmation of identity.

2. The system of claim 1, wherein said camera is structured to photograph two eyes of said animate being, said data processing unit is operable to separately process image input into processed data signals representative of each eye.

3. The system of claim 2, wherein the same parameters are examined for each eye for identification purposes.

4. The system of claim 2, wherein different parameters are examined for each eye for identification purposes.

5. The system of claim 4, wherein the different parameters are selected for each eye as a function of being representative of a distinguishing characteristic(s) or feature(s) associated with that eye.

6. The system of claim 1, further comprising at least one of a card reading unit, and a key input unit for initially receiving inputted identifier information for transfer to said control unit.

7. The system of claim 1, wherein said iris image pickup unit includes a light source operated by the control unit in conjunction with the camera to capture, in succession, a plurality of iris images to create said input image signals.

8. The system of claim 7, wherein said light source is an infrared source.

9. The system of claim 1, wherein said predetermined personal information includes positioning data interfaced with said iris image pick-up unit through said control unit to automatically align the camera the user'"'"'s eye.

10. The system of claim 1, wherein said processed data is representative of at least two of said parameters.

11. The system of claim 10, wherein said processed data is representative of all of said parameters.

12. The system of claim 1, wherein the frequency transformation method utilizes a Wavelet Transform.

13. The system of claim 12, wherein the frequency transformation method utilizes a Haar Transform.

14. The system of claim 13, wherein low frequency components of two-dimensional Haar Transform coefficients are obtained for identification purposes from a selected one of the input image signals.

15. The system of claim 13 wherein the Haar Transform is selected form a class of signum Haar functions.

16. The system of claim 13, wherein the Haar Transform is processed with a Butterfly Structure of a Transformation Flow Graph.

17. The system of claim 13, wherein at least a selected one of the input image signals is analyzed with a variable multi-sector system of spectral conversion using said Haar Transform functions.

18. The system of claim 17, wherein the multi-sector system of spectral analysis enables a variable selection of sectors of the iris representative of visible portions of the iris for analysis purposes that are not garbled by interference.

19. The system of claim 18, wherein said multi-sector system of spectral analysis enables defects or interferences with borders to be identified and excluded from the identification analysis.

20. The system of claim 19, wherein a selected one of the input iris images, for said spectral analysis purposes, is divided into an outer ring having an outer border located approximately at the border of the sclera-iris, and an inner circular portion, spaced inwardly from the outer ring, and having a radius spaced inwardly from the outer border by a predetermined distance.

21. The system of claim 20, wherein said predetermined distance is approximately 30-80 pixels.

22. The system of claim 21, wherein the outer ring, and an area within the circular zone disposed between the circular zone border with the outer ring and the periphery of the pupil, are each divided into a plurality of sectors (n) and (p) respectively, wherein n is the same or a different value from p, creating a total of n+p sectors wherein a predetermined number (m²) of Haar coefficients are calculated using a Haar Transform forming a m×

m matrix.

23. The system of claim 22, wherein n=16, p=16 and m=32, and for each of said 32 sectors, 1024 Haar function coefficients are calculated using a Haar Transform and from a 32×

32 matrix.

24. The system of claim 23, wherein sectors occluded or interfered with by eyelids, eyelashes and the like, are rejected through adjacent sector Haar coefficient comparison.

25. The system of claim 22, wherein, by comparison of adjacent sector Haar coefficients, a sector is rejected as defective during analysis if a predetermined sharp variation of high frequency coefficients is detected.

26. The system of claim 25, wherein after removal of rejected sectors from the analysis, a subset of a complete set of m² Haar coefficients are selected to create a predetermined number of coefficients from the m×

m matrix of m² Haar coefficients selected for analysis purposes.

27. The system of claim 26, wherein m=32 and said subset includes 31 coefficients selected from the 32×

32 matrix of Haar coefficients.

28. The system of claim 26, wherein the selection of the predetermined number of coefficients is used to create an iris reference record.

29. The system of claim 28, wherein said predetermined number of coefficients are representative of a selected low frequency zone utilized for identification purposes.

30. The system of claim 1, wherein the processed data includes the shape of the pupil determined using at least one of a curve fitting and an edge detection algorithm.

31. The systems of claim 30, wherein the processed data includes the ellipticity of the pupil and orientation of the ellipse major axis.

32. The system of claim 30, wherein flat portions, if any, along the periphery of the pupil are recognized for identification purposes.

33. The system of claim 1, wherein said control unit calculates information representative of pupillary reaction by utilizing the input image signals to generate a pupil histogram or pupillogram representative of the average contraction and dilation of a pupil over time in response to light stimulus.

34. The system of claim 33, wherein said pupillogram confirms image scanning of a live animate being.

35. The system of claim 1, wherein said camera has a variable capturing or flex zone for auto focusing.

36. The system of claim 1, wherein said camera further includes a second lens having a focal length greater than 5 millimeters to prevent degradation of auto focusing as a result of movement of the user'"'"'s eye.

37. The system of claim 36, wherein a plurality infrared of light sources are arranged in a circular array around the periphery of the second camera lens.

38. The system of claim 1, wherein said iris image pick-up unit further comprises a vision guide unit for aligning the user'"'"'s eye with the camera lens.

39. A system for testing for the presence of drugs or alcohol within a person, comprising:

a) a control unit for receiving identification information identifying the person;

b) an iris image pick-up unit including a camera operated by the control unit for capturing iris images to create input image signals;

c) a data processing unit for preprocessing the input image signals into processed data;

wherein said control unit is operable to calculate the processed data taken as a result of the processing of said input image signals to represent the average contraction and dilation of the iris pupil in response to a light stimulus over time to thereby determine whether the processed data is indicative of actual or recent intoxication since the shape of the curve of the pupillogram is different when a person is intoxicated with alcohol or drugs relative to the shape of the curve when the person is alcohol or drug free.

40. The system of claim 39, wherein said control unit is operable to compare characteristics calculated from the pupillogram of the left and right iris pupil to thereby determine whether the processed data is indicative of actual or recent intoxication since the ratio of the left iris pupil characteristics to the right iris pupil characteristics is different when a person is intoxicated with alcohol or drugs relative to the shape of the curve when the person is alcohol or drug free.

41. The system of claim 40, wherein said characteristics for drug detection include at least one selected from the group consisting of (1) D_AB, (2) %A₁, (3) %A₂, (4) S_P, (5) T₂-T₀, and (6) T_M.

42. A method of testing for the presence of at least one of drugs and alcohol in a person'"'"'s body, comprising the steps of:

a) obtaining at a different time a plurality of images of substantially the same portion of the iris and pupil of a person;

b) processing said plurality of images into a pupil histogram;

c) calculate the characteristics of said pupil histogram processed in step (b); and

d) confirming the presence of at least drugs or alcohol based on said characteristics of step (c).

43. The method of claim 42, wherein changes in the flatness characteristics of a curve associated with said pupil histogram are indicative of the presence of at least one of drugs and alcohol.

46. The method of claim 44, comprising the further step of initiating step (b) of claim 42 by matching inputted password information with previously stored information of an identifiable person.

60. The method of claim 59, wherein the processing step includes, after removal of rejected sectors determining, a subset of a complete predetermined number of coefficients which are selected for analysis purposes and the selection of the predetermined number of coefficients in the subset for each selected sector is used to create an iris reference record used in comparing step (d) of claim 42.

61. The method of claim 60, wherein coefficients representative of a selected frequency zone of selected sectors are utilized for identification purposes.

67. The method of claim 42, wherein step a) further comprises obtaining images of the iris and pupil of the left and right eyes of a person and step d) further comprises comparing characteristics calculated from the pupillogram of the left and right iris pupil to thereby determine whether the processed data is indicative of actual or recent intoxication since the ratio of the left iris pupil characteristics to the right iris pupil characteristics is different when a person is intoxicated with alcohol or drugs relative to the shape of the curve when the person is alcohol or drug free.

68. The method of claim 67, wherein said characteristics for drug detection include at least one selected from the group consisting of (1) D_AB, (2) %A₁, (3) %A₂, (4) S_P, (5) T₂-T₀, and (6) T_M.

44. A method of confirming the identity of an animate being, comprising the steps of:

a) initially determining whether the animate being has an identity corresponding to an animate being identified in a data base;

b) if step (a) is yes, then obtaining a plurality of images representative of at least a portion of the iris and pupil of the being'"'"'s eye;

c) processing said plurality of images to obtain iris identification parameter information selected from the group consisting of at least one of the density and texture form of the iris fiber structure using a frequency transformation method, pupillary reaction, the shape of the pupil, autonomous nervous wreath reaction, shape of the autonomous nervous wreath, the existence of lacuna, the location of the lacuna, and the shape of the lacuna;

d) comparing predetermined characteristics of said previously obtained iris identification information with said iris identification information obtained in step (c); and

e) confirming whether there is a match indication of data compared in step (d).

45. The method of claim 44, comprising the further step of obtaining said plurality of images for each eye.

47. The method of claim 44, comprising the further step of illuminating the eye with a light source followed by capturing, in succession, a plurality of said iris images.

48. The method of claim 47, wherein an infrared light source is used for illuminating.

49. The method of claim 44, comprising the further step of aligning the camera with the user'"'"'s eye to obtain said plurality of images.

50. The method of claim 44, wherein said plurality of images are processed to obtain information pertaining to at least two of said identification parameters.

51. The method of claim 44, wherein each of said parameters are processed for identification purposes.

52. The method of claim 44, wherein a Wavelet Transform is used in processing step (c).

53. The method of claim 52, wherein a Haar Transform is used in processing step (c).

54. The method of claim 53, wherein the processing step includes obtaining low frequency components of two dimensional Haar Transform coefficients from a selected one of the input image signals.

55. The method of claim 53, wherein the processing step includes selecting the Haar Transform from a class of signum Haar functions.

56. The method of claim 53, where the processing step utilizes a variable multi-sector system of spectral analysis to enable a variable selection of sectors of the iris representative of visible portions of the iris to occur for analysis purposes that are not garbled by interference.

57. The method of claim 56, comprising the further step of utilizing said variable multi-sector system of spectral analysis to exclude from the identification analysis defects or interferences with borders to be identified.

58. The method of claim 56, wherein the processing step includes dividing the iris image into a predetermined number of sectors located within an outer ring and a circular area formed concentric with said outer ring which includes the pupil.

59. The method of claim 58, wherein said sectors are analyzed on a sector by adjacent sector basil and certain sectors are rejected as defective if a predetermined sharp variation of high frequency coefficients is detected.

62. The method of claim 44, wherein the processing step includes analysis of the shape of the iris pupil utilizing at least one of a curve fitting and edge detection algorithms.

63. The method of claim 62, wherein the processing step includes detecting the ellipticity of the pupil and orientation of the ellipse major axis.

64. The method of claim 63, wherein the processing step utilizes determining the existence of flat portions along the periphery of the pupil.

65. The method of claim 44, wherein said plurality of iris images are acquired utilizing auto-focusing of a camera with a variable capturing or flex zone.

66. The method of claim 44, comprising the further step of utilizing previously stored information to automatically orient the eye with a source of obtaining said plurality of images in step (b).

70. The method of claim 69, wherein the image acquiring process comprises the steps of:

automatically adjusting the camera position according to the user'"'"'s previously stored personal information obtained from step (c) of claim 65;

aligning and automatically adjusting the focus of the camera;

switching on a light source to guide movement of the pupil and autonomous nervous wreath; and

extinguishing the light source.

72. The method of claim 69, wherein step (d) of claim 65 comprises the steps of:

computing parameters for identifying the shape of the autonomous nervous wreath by transforming a two-dimensional image signal from the detected autonomous nervous wreath zone with a Medial Axis Transform, and computing the shape of the autonomous nervous wreath at the detected zone.

69. A method of identifying an iris of a user based on a reaction of a pupil and an autonomous nervous wreath associated with the iris comprising the steps of:

a) confirming a user'"'"'s identity by searching for previously stored personal information from a database properly accessed by the user;

b) acquiring a series of images of the user'"'"'s iris with a camera;

c) initiating an iris fiber structure confirmation process to ascertain the user'"'"'s identity by selecting an image signal of a zone of the iris from a selected one of the acquired images of the iris, and determining identity confirmation parameters from the image signal of the selected zone;

d) initiating a pupillary and autonomous nervous wreath reaction confirmation process to ascertain the user'"'"'s identity by detecting the zone of the pupil and autonomous nervous wreath from a selected one of the acquired iris images, computing the dynamic reaction(contraction and dilation) of the pupil and autonomous nervous wreath from the selected image signal of the detected zone of the pupil and autonomous nervous wreath, and determining associated identification parameters.

e) confirming the user'"'"'s identity by comparing the identification parameters with previous stored identification parameters as personal information.

71. The method of claim 69, wherein the iris fiber structure confirmation process comprises the steps of:

determining identification parameters out of Wavelet Transform coefficients associated with the corresponding iris fiber structure by transforming a selected image signal of the iris with a Haar Transform; and

confirming the user'"'"'s identity by searching for previous stored corresponding parameters from the database.

73. A method of identifying an iris based on a reaction of a pupil and autonomous nervous wreath within the iris comprising the steps of:

a) confirming a user'"'"'s identity by searching for previously stored personal information from a database properly accessed by the user;

b) acquiring a series of images of the iris with a camera;

c) initiating a pupillary and autonomous nervous wreath reaction confirmation process to ascertain the user'"'"'s identity by detecting the zone of the pupil and autonomous nervous wreath from a selected one of the acquired iris images, computing the dynamic reaction(contraction and dilation) of the pupil and autonomous nervous wreath from the selected image signal of the detected zone of the pupil and autonomous nervous wreath, and determining associated identification parameters; and

d) confirming the user'"'"'s identity by comparing the identification parameters with previous stored identification parameters as personal information.

74. A method of identifying an iris, comprising the steps of:

a) confirming a user'"'"'s identity by searching for previously stored personal information from a database properly accessed by the user;

b) acquiring a series of images of the user'"'"'s iris with a camera; and

c) initiating a first lacuna confirmation process to ascertain the user'"'"'s identity, by detecting a lacuna zone from an acquired image if the lacuna exists, and determining identity confirmation parameters based on the shape and location of the lacuna.

75. The method of claim 74, further comprising a second lacuna confirmation process, if the lacuna does not exist, of confirming the user'"'"'s identity if there also does not exist a lacuna in the reference iris, and rejecting the user as improper if there exists a lacuna in the reference iris.

76. The method of claim 75, comprising the further steps of:

detecting a zone of the pupil and autonomous nervous wreath by computing the central portion of a acquired iris image;

determining the identification parameters by computing the reaction (dilation or contraction) of the moving pupil and autonomous nervous wreath on the detected zone; and

confirming the user'"'"'s identity by searching the corresponding parameters from the database.

77. The method of claim 75, which comprises the further steps of:

detecting a zone of the autonomous nervous wreath out of the zone relating to a selected iris for analysis;

computing the parameters for identifying the shape of the autonomous nervous wreath by transforming a two-dimensional image signal on the detected autonomous nervous wreath zone with a Medial Axis Transform, and computing the shape of the autonomous nervous shape at the detected zone; and

confirming the user'"'"'s identity by searching the corresponding parameters from the database.

78. The method of claim 75, wherein the first lacuna confirmation process comprises the steps of:

judging whether a lacuna exists or not by detecting an edge of the iris image from the selected acquired image signal of the iris;

detecting a lacuna zone, if the lacuna exists as a result of the judging step;

computing the identification parameters on the basis of the shape and location of the lacuna after transforming a two-dimensional image signal on the detected lacuna zone with a Medial Axis Transform; and

confirming the user'"'"'s identity by searching the corresponding parameters out of the database.

79. A system for confirming the identity of an animate being through iris scanning, comprising;

a) a control unit for receiving identifier information identifying the animate being, and a data storage unit including a data base accessed by the control unit for containing predetermined personal information associated with an identifiable being for comparison with identifier information;

b) an iris image pick-up unit including a binoculars camera operated by the control unit when the identifier information corresponds to the predetermined information for capturing left and right eye iris images to create input image signals; and

c) a data processing unit for preprocessing the input image signals into processed data.