Biometric information obtaining apparatus and biometric information verification apparatus

• US 7,627,150 B2
• Filed: 12/22/2004
• Issued: 12/01/2009
• Est. Priority Date: 09/17/2002
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Abiko, Yukihiro, Fujii, Yusaku, Morihara, Takashi
• Primary Examiner(s): Werner; Brian P
• Assistant Examiner(s): DULANEY, KATHLEEN YUAN
• Application Number:
  US11/018,601
• Publication Number:
  US 20050100200A1
• Time in Patent Office: 1,805 Days
• Field of Search: 382/124, 382/284, 345/629
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement

Abstract

The object is to obtain undistorted images in high speed using a small amount of memory capacity, to realize high-quality characteristic information verification. The apparatus, which obtains information needed for user verification from partial images that are successively captured by a sweep-type fingerprint sensor from a fingertip, includes image obtaining means which captures successive partial images of biometric information; characteristic extracting means which obtains, from the captured partial images, characteristics and positions of the characteristics; detecting means which detects relative position information of partial images based on characteristics contained in a region in which the partial images overlap; and correcting means which calculates the amount of distortion of the characteristics based on the detected relative position information and on the positions of the characteristics in each partial image, and which corrects the positions of the characteristics in each individual partial image based on the calculated distortion amount.

Claims

1. A biometric information obtaining apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information from an object moving relative to said image obtaining means while keeping contact with an image capturing surface;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap; and

correcting means which obtains a distance between same characteristics existing in a region in which the two or more partial images overlap based on the relative position information detected by said relative position information detecting means and on the position of the characteristic in the individual partial image and then calculates an amount of distortion of the characteristic caused by deformation of the object resulting from a frictional force accompanying the contact movement of the object based on the distance, and which corrects the position of the characteristic in the individual partial image based on the calculated distortion amount so as to eliminate the distortion caused by deformation of the object resulting from the frictional force when said image obtaining means is capturing the plurality of successive partial images.

2. A biometric information obtaining apparatus as set forth in claim 1,

wherein said image obtaining means captures the plurality of successive partial images from an object that is moving with respect to said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises removing means which removes a pattern image that is contained in the plural partial images captured by said image obtaining means and does not move, before said characteristic extracting means extracts the characteristic.

3. A biometric information obtaining apparatus as set forth in claim 1, wherein said characteristic extracting means extracts, as said characteristic, the foreground of the individual partial image and edges of the foreground.

4. A biometric information obtaining apparatus as set forth in claim 1, wherein said characteristic extracting means extracts, as said characteristic, an endpoint and a bifurcation in a pattern which is obtained by thinning the foreground of the individual partial image.

5. A biometric information obtaining apparatus as set forth in claim 1, wherein said relative position information detecting means detects the relative position information of the two or more partial images, which are captured successively by said image obtaining means, based on one or more relative position information items detected by the time immediately before the detection of the relative position information of said two or more partial images.

6. A biometric information obtaining apparatus as set forth in claim 1, wherein said relative position information detecting means detects relative position information of the two or more partial images, which are captured successively by said image obtaining means, based on a predicted relative position information to be detected next, said predicted relative position information being estimated based on one or more relative position information items detected by the time immediately before the detection of the relative position information of said two or more partial images.

7. A biometric information obtaining apparatus as set forth in claim 1, wherein said relative position information detecting means divides each of the two or more partial images, which are captured successively by said image obtaining means, into two or more partial regions which share a common overlapping area, and detects the relative position information separately in the divided two or more partial regions.

8. A biometric information obtaining apparatus as set forth in claim 1,

wherein said image obtaining means captures the plurality of successive partial images from an object that is moving with respect to said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises moving object detecting means which detects the presence or absence of a moving object which is moving with respect to said image obtaining means, based on the plural partial images captured by said image obtaining means.

9. A biometric information obtaining apparatus as set forth in claim 1,

wherein said image obtaining means captures the plurality of successive partial images from an object that is moving with respect to said image obtaining means while being in contact with said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises friction reducing means which is operable to reduce friction caused by the movement of the object.

10. A biometric information obtaining apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information from an object moving relative to said image obtaining means;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap; and

correcting means which corrects the position of the characteristic in the individual partial image, based on a time interval at which said image obtaining means obtains the individual partial image, on a delay in capturing the individual partial image by said image obtaining means, and on the relative position information detected by said relative position information detecting means, thereby correcting distortion of the individual partial image caused by the delay in capturing the individual partial image, the delay occurring during a time from the start of capturing a single partial image to the end thereof, and relative movement of the object and the image obtaining means.

11. A biometric information obtaining apparatus as set forth in claim 10,

wherein said relative position information detecting means divides each of the two or more partial images, which are captured successively by said image obtaining means, into two or more partial regions which share a common overlapping area, and detects the relative position information separately in the divided two or more partial regions,

wherein said correcting means corrects the position of the characteristic in the partial regions separately, so that distortion of the individual partial image due to the delay in capturing the individual partial image by said image obtaining means is corrected.

12. A biometric information verification apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information of a user to be verified from an object moving relative to said image obtaining means while keeping contact with an image capturing device;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap;

correcting means which obtains a distance between same characteristics existing in a region in which the two or more partial images overlap based on the relative position information detected by said relative position information detecting means and on the position of the characteristic in the individual partial image and then calculates an amount of distortion of the characteristic caused by deformation of the object resulting from a frictional force accompanying the contact movement of the object based on the distance, and which corrects the position of the characteristic in the individual partial image based on the calculated distortion amount so as to eliminate the distortion caused by deformation of the object resulting from the frictional force when said image obtaining means is capturing the plurality of successive partial images;

generating means which generates either or both of registration data and verification data for user verification, by using the characteristic extracted by said characteristic extracting means and the corrected position of the characteristic obtained by said correcting means; and

verifying means which performs verification process, using either or both of the registration data and the verification data generated by said generating means, to verify the user.

13. A biometric information verification apparatus as set forth in claim 12,

wherein said image obtaining means captures the plurality of successive partial images from an object of the user to be verified, which object is moving with respect to said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises removing means which removes a pattern image that is contained in the plural partial images captured by said image obtaining means and does not move, before said characteristic extracting means extracts the characteristic.

14. A biometric information verification apparatus as set forth in claim 12, wherein said characteristic extracting means extracts, as said characteristic, the foreground of the individual partial image and edges of the foreground.

15. A biometric information verification apparatus as set forth in claim 12, wherein said characteristic extracting means extracts, as said characteristic, an endpoint and a bifurcation in a pattern which is obtained by thinning the foreground of the individual partial image.

16. A biometric information verification apparatus as set forth in claim 12, wherein said relative position information detecting means detects the relative position information of the two or more partial images, which are captured successively by said image obtaining means, based on one or more relative position information items detected by the time immediately before the detection of the relative position information of said two or more partial images.

17. A biometric information verification apparatus as set forth in claim 12, wherein said relative position information detecting means detects relative position information of the two or more partial images, which are captured successively by said image obtaining means, based on a predicted relative position information to be detected next, said predicted relative position information being estimated based on one or more relative position information items detected by the time immediately before the detection of the relative position information of said two or more partial images.

18. A biometric information verification apparatus as set forth in claim 12, wherein said relative position information detecting means divides each of the two or more partial images, which are captured successively by said image obtaining means, into two or more partial regions which share a common overlapping area, and detects the relative position information separately in the divided two or more partial regions.

19. A biometric information obtaining apparatus as set forth in claim 12,

wherein said image obtaining means captures the plurality of successive partial images from an object of the user to be verified, which object is moving with respect to said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises moving object detecting means which detects the presence or absence of a moving object which is moving with respect to said image obtaining means, based on the plural partial images captured by said image obtaining means.

20. A biometric information obtaining apparatus as set forth in claim 12,

wherein said verifying means performs the verification process preferentially using the characteristic and the relative position information which are obtained from a partial image captured early in time by said image obtaining means.

21. A biometric information obtaining apparatus as set forth in claim 20,

wherein said verifying means terminates the verification process at the time the verification result of the user is confirmed.

22. A biometric information obtaining apparatus as set forth in claim 12,

wherein said image obtaining means captures the plurality of successive partial images from an object of the user to be verified, which object is moving with respect to said image obtaining means while being in contact with said image obtaining means, and

wherein said biometric information obtaining apparatus further comprises friction reducing means which is operable to reduce friction caused by the movement of the object.

23. A biometric information obtaining apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information from an object moving relative to said image obtaining means while keeping contact with an image capturing surface;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap; and

correcting means which obtains a distance between same characteristics existing in a region in which the two or more partial images overlap based on the relative position information detected by said relative position information detecting means and on the position of the characteristic in the individual partial image and then calculates an amount of distortion of the characteristic caused by deformation of the object resulting from a frictional force accompanying the contact movement of the object based on the distance, and which corrects the position of the characteristic in the individual partial image based on the calculated distortion amount, and

which corrects the position of the characteristic in the individual partial image, based on a time interval at which said image obtaining means obtains the individual partial image, on a delay in capturing the individual partial image by said image obtaining means, and on the relative position information detected by said relative position information detecting means, so that distortion of the individual partial image due to the delay in capturing the individual partial image by said image obtaining means is corrected so as to eliminate the distortion caused by deformation of the object resulting from the frictional force when said image obtaining means is capturing the plurality of successive partial images.

24. A biometric information obtaining apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information from an object moving relative to said image obtaining means while keeping contact with an image capturing surface;

correcting means which obtains a distance between same characteristics existing in a region in which two or more partial images overlap based on detected relative position information and on a position of a characteristic in an individual partial image and then calculates an amount of distortion of a characteristic of a partial image caused by deformation of the object resulting from a frictional force accompanying the contact movement of the object based on a distance, and which corrects the position of the characteristic in an individual partial image based on a calculated distortion amount so as to eliminate the distortion caused by deformation of the object resulting from the frictional force when said image obtaining means is capturing the plurality of successive partial images; and

friction reducing means which is operable to reduce friction caused by the movement of the object.

25. A biometric information verification apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information of a user to be verified from an object moving relative to said image obtaining means;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap;

correcting means which corrects the position of the characteristic in the individual partial image, based on a time interval at which said image obtaining means obtains the individual partial image, on a delay in capturing the individual partial image by said image obtaining means, and on the relative position information detected by said relative position information detecting means, thereby detecting distortion of the individual partial image caused by the delay in capturing the individual partial image, the delay occurring during a time from the start of capturing a single partial image to the end thereof, and relative movement of the object and the image obtaining means;

generating means which generates either or both of registration data and verification data for user verification, by using the characteristic extracted by said characteristic extracting means and the corrected position of the characteristic obtained by said correcting means; and

verifying means which performs verification process, using either or both of the registration data and the verification data generated by said generating means, to verify the user.

26. A biometric information verification apparatus, comprising:

image obtaining means which captures a plurality of successive partial images of successive portions of biometric information of a user to be verified from an object moving relative to said image obtaining means while keeping contact with an image capturing surface;

characteristic extracting means which obtains, from an individual partial image obtained by said image obtaining means, a characteristic contained in said individual partial image and a position of the characteristic;

relative position information detecting means which detects relative position information of two or more of the partial images, obtained by said image obtaining means, based on the characteristic contained in a region in which said two or more partial images overlap;

correcting means which obtains a distance between same characteristics existing in a region in which the two or more partial images overlap based on the relative position information detected by said relative position information detecting means and on the position of the characteristic in the individual partial image and then calculates an amount of distortion of the characteristic caused by deformation of the object resulting from a frictional force accompanying the contact movement of the object based on the distance, and which corrects the position of the characteristic in the individual partial image, based on the calculated distortion amount and

which corrects the position of the characteristic in the individual partial image, based on a time interval at which said image obtaining means obtains the individual partial image, on a delay in capturing the individual partial image by said image obtaining means, and on the relative position information detected by said relative position information detecting means, so that distortion of the individual partial image due to the delay in capturing the individual partial image by said image obtaining means is corrected so as to eliminate the distortion caused by deformation of the object resulting from the frictional force when said image obtaining means is capturing the plurality of successive partial images;

generating means which generates either or both of registration data and verification data for user verification, by using the characteristic extracted by said characteristic extracting means and the corrected position of the characteristic obtained by said correcting means; and

verifying means which performs verification process, using either or both of the registration data and the verification data generated by said generating means, to verify the user.

27. A method for correcting distortion in an image, comprising:

capturing a plurality of successive partial images, using an image obtaining apparatus, of successive portions of biometric information from an object moving relative to the image obtaining apparatus while keeping contact with an image capturing surface;

detecting relative position information of two or more of the partial images based on an extracted characteristic contained in a region in which said two or more partial images overlap;

obtaining a distance between same characteristics existing in the region in which the two or more partial images overlap based on the relative position information and on a position of the characteristic in an individual partial image;

calculating an amount of distortion of the extracted characteristic caused by deformation resulting from a frictional force accompanying the contact movement of the object based on the distance; and

correcting a position of the characteristic caused by deformation of the object in the partial image based on the distortion amount so as to eliminate distortion caused by deformation of the object resulting from the frictional force when the plurality of successive partial images are captured using the image obtaining apparatus.