Fingerprint verification device
View Patent ↗A fingerprint verification device includes a fingerprint sensor including an imaging surface. The fingerprint sensor is configured to capture images of a user's finger when the finger is swiped against the imaging surface. A memory stores fingerprint data. A controller compares minutiae in the captured images with the stored fingerprint data to verify the user's identity. The controller is configured to determine whether the finger is a real human finger based on the spacing of minutiae in the captured images.
1. A method of recognizing a fingerprint, the method comprising:
providing a fingerprint sensor;
capturing a first set of images of a finger when the finger is swiped in a first direction on the fingerprint sensor;
stitching the first set of images together to form a first stitched image;
capturing a second set of images of the finger when the finger is swiped in a second direction on the fingerprint sensor;
stitching the second set of images together to form a second stitched image;
wherein the finger is deformed when swiped on the fingerprint sensor and wherein the deformation of the finger when swiped in the first direction is different from the deformation of the finger when swiped in the second direction;
comparing minutiae in the first and the second stitched images to stored fingerprint data;
determining whether the finger is recognizable based on the comparison; and
generating movement information with the fingerprint sensor, the movement information indicative of movement of the finger on the fingerprint sensor;
wherein the first and the second stitched images are formed based on the movement information.
2. The method of claim 1 , and further comprising:
comparing the distance between features in the first stitched image with the distance between features in the second stitched image.
3. The method of claim 2 , and further comprising:
determining whether the finger is a real human finger based on the comparison of the distance between features, and the stored fingerprint data.
4. The method of claim 1 , and further comprising:
calculating a delta value representing a difference between the distance between features in the first stitched image and the distance between features in the second stitched image.
5. The method of claim 4 , and further comprising:
comparing the delta value to the stored fingerprint data to determine whether the finger is a real human finger.
6. The method of claim 5 , and further comprising:
calculating a first value representing the distance between a first minutia and a second minutia in the first stitched image;
calculating a second value representing the distance between the first minutia and the second minutia in the second stitched image; and
wherein the delta value represents the difference between the first value and the second value.
7. The method of claim 1 wherein:
the swipe in one of the first and second directions causes narrowing of ridge pitch and moving of minutiae closer together; and
the swipe in the other of the first and second directions causes widening of ridge pitch and moving of minutiae farther apart.
8. A method of recognizing a fingerprint, the method comprising:
providing a fingerprint sensor;
capturing a first set of images of a finger when the finger is swiped in a first direction on the fingerprint sensor;
stitching the first set of images together to form a first stitched image;
capturing a second set of images of the finger when the finger is swiped in a second direction on the fingerprint sensor;
stitching the second set of images together to form a second stitched image;
comparing minutiae in the first and the second stitched images to stored fingerprint data;
determining whether the finger is recognizable based on the comparison; and
calculating a delta value representing a difference between the distance between features in the first stitched image and the distance between features in the second stitched image.
9. The method of claim 8 , and further comprising:
comparing the delta value to the stored fingerprint data to determine whether the finger is a real human finger.
10. The method of claim 9 , and further comprising:
calculating a first value representing the distance between a first minutia and a second minutia in the first stitched image;
calculating a second value representing the distance between the first minutia and the second minutia in the second stitched image; and
wherein the delta value represents the difference between the first value and the second value.