Personal identification device and method

• US 20020028004A1
• Filed: 09/05/2001
• Published: 03/07/2002
• Est. Priority Date: 09/06/2000
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Miyatake, Takafumi, Miura, Naoto, Nagasaka, Akio
• Granted Patent: US 6,993,160 B2
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G06V 40/1312 direct reading, e.g. contactless acquisition
• CPC Class Codes: G06V 40/1341 Sensing with light passing through the finger
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

The invention aims at providing personal identification in environments where non-contact is required, with high accuracy even though using a finger vein pattern images unclear and susceptible to positional deviations, wherein it has: a means for acquiring finger vein patterns without contact; a means for carrying out rotational correction using the outline of a finger as a method of taking out a vein pattern contained in the acquired image; a means for normalizing the position of the finger image with reference to the fingertip; a means for acquiring an overall vein pattern statistically by repetitively tracking regions of dark luminance intensities for a desired length from a desired position in the image; a matching means for comparing regions where vein patterns manifest vivid features; and a means for independent matching of subregions and evaluating positional deviations where matching is recognized.

Claims

1. A personal identification device comprising:

a storage for storing vein patterns of registered finger images,

an interface provided with a light source and a camera for receiving light transmitted through fingers, and

means for extracting a vein pattern contained in the received image of light transmitted through the fingers and identifying a person by collating the extracted vein pattern with the vein patterns of registered finger images, wherein;

said interface has a slot into which fingers are inserted, and said light source and said camera are arranged opposite each other with the slot between them.

2. The personal identification device, as set forth in claim 1, wherein the slot of said interface is formed in such a way that at least one finger of a person to be identified can be inserted by a motion centering on his or her shoulder, elbow or wrist.

3. The personal identification device, as set forth in claim 2 wherein the slot of said interface is formed in an arc shape along the track of inserting the person'"'"'s hand.

4. The personal identification device, as set forth in claim 2, wherein the slot of said interface is formed in a vertical direction to the ground.

5. The personal identification device, as set forth in claim 4, wherein said means for identifying a person corrects, with respect to the received finger image, any rotation occurring on the plane of imaging at the time said finger is inserted into said interface, and extracts a vein pattern contained in said finger image having undergone rotational correction to identify the person.

13. The personal identification device, as set forth in claim 1, wherein the vein pattern of said registered finger image is registered in an IC card held by the person to be identified, and inputted to said storage at the time of personal identification.

14. The personal identification device, as set forth in claim 1, wherein identifying information is read out of the IC card held by the person to be identified, and vein pattern of a registered finger image corresponding to said identifying information is read out of said storage for use in collation.

15. The personal identification device, as set forth in claim 1, wherein said interface has a means for rotating said camera, and performs personal identification using finger images received in many directions.

16. The personal identification device, as set forth in claim 1, wherein personal identification is performed using vein pattern of a plurality of fingers.

6. A personal identification device comprising:

a storage for storing vein patterns of registered finger images;

interface provided with a light source and a camera for receiving light transmitted through fingers; and

means for performing personal identification by correcting, with respect to the received finger image, any rotation occurring on the plane of imaging at the time said finger is inserted into said interface, extracting a vein pattern contained in said finger image having undergone rotational correction to identify the person, and collating the extracted vein pattern with the vein patterns of said registered finger images.

7. The personal identification device, as set forth in claim 6, wherein said means for performing personal identification curves out, with respect to a finger image having undergone rotational correction, a finger image with reference to the fingertip and the central axis of the finger, and extracting a vein pattern contained in this curved-out finger image.

8. The personal identification device, as set forth in claim 6, wherein said means for performing personal identification extracts a vein pattern by finding an initial location by selecting a pixel having the lowest luminance intensity among a plurality of pixels in the image, repetitively identifying the regions of lowest luminance intensity around the initial location, determining which regions are identified more often than other regions, and recognizing the sum of regions determined to be identified more often as blood vessels.

9. The personal identification device, as set forth in claim 6, wherein said means for performing personal identification extracts a vein pattern by finding an initial location by selecting a pixel having the highest luminance intensity among a plurality of pixels in the image at a certain probability determined by random number, repetitively identifying the regions of lowest luminance intensity around the initial location, determining which regions are identified more often than other regions, and recognizing the sum of regions determined to be identified more often as blood vessels determined by a random number.

10. The personal identification device, as set forth in claim 8, wherein said means for performing personal identification repetitively identifying regions of lowest luminance intensity around the initial location for a length determined by a random number.

11. The personal identification device, as set forth in claim 8, wherein said means for performing personal identification, in collating vein patterns, classifies said finger images into blood vessel regions, non-blood vessel regions and ambiguous regions, and evaluates the overlapping of said blood vessel regions and said non-blood vessel regions when said finger image is superposed over a registered finger image.

12. The personal identification device, as set forth in claim 8, wherein said means for performing personal identification, in collating extracted vein patterns, divides said finger image and registered finger images into subregions and performs independent collation for each subregion.

19. The personal identification device, as set forth in claim 6, wherein said means for identifying a person carries out rotational correction by using finger outline information of the received finger image.

20. The personal identification device, as set forth in claim 19, wherein said means for identifying a person performs rotational correction by using an approximated straight line of an upper outline of the received finger image.

21. The personal identification device, as set forth in claim 20, wherein said means for identifying a person performs rotational correction by determining an inclination of the finger at the time of imaging by using the approximated straight line of the upper outline of the received finger image, and correcting the inclination to a constant in every received finger image.

17. A security system comprising:

a storage for storing vein patterns of registered finger images,

an interface provided with a light source and a camera for receiving light transmitted through fingers without contact,

means for extracting a vein pattern contained in the received image of light transmitted through the fingers and identifying a person by collating the extracted vein pattern with the vein patterns of registered finger images, and

means for controlling a door, wherein said means for controlling the door enables the door to be opened when said means for identifying a person judges that an extracted vein pattern is identical with the vein pattern of a registered finger image.

18. A personal identification method for performing personal identification by:

receiving light transmitted through fingers,

correcting, with respect to the received finger image, any rotation occurring on the plane of imaging at the time said finger is inserted into said image receiving device, and

collating a vein pattern contained in said finger image with the vein patterns of said registered finger images.

22. A security system comprising:

a storage for storing vein patterns of registered finger images,

an interface provided with a light source and a camera for receiving light transmitted through fingers,

an IC card reader for reading identifying information from an IC card held by the person to be identified, and

means for extracting a vein pattern contained in the received image of light transmitted through the fingers and identifying a person by collating the extracted vein pattern with the vein pattern of the registered finger image,

wherein said vein pattern of registered finger image is read from said storage according to said identifying information.

23. The security system, as set forth in claim 22, further comprising a door controller which causes a door to open when said means for identifying a person judges that an extracted vein pattern is identical with the vein pattern of a finger image that is read.

24. The security system, as set forth in claim 23, wherein said means for identifying a person corrects, with respect to the received finger image, any rotation occurring on the plane of imaging at the time said finger is inserted into said interface, and extracts a vein pattern contained in said finger image having undergone rotational correction to identify the person.

26. The program according to claim 25, wherein the step of repetitively identifying regions of lowest luminance intensity is performed for a length determined by a random number.

27. The program according to claim 25, wherein a direction in which blood vessels lie is previously known and the step of repetitively identifying regions of lowest luminance intensity is performed along the direction in which blood vessels lie.

25. A program stored on a computer readable storage medium for executing a method for acquiring blood vessels in an image, the program comprising the steps of:

finding an initial location by selecting a pixel having the lowest luminance intensity among a plurality of pixels in the image;

repetitively identifying the regions of lowest luminance intensity around the initial location;

determining which regions are identified more often than other regions; and

recognizing the sum of regions determined to be identified more often as blood vessels.