Fingerprint image conversion device, fingerprint image conversion system, fingerprint image conversion method, and fingerprint image conversion program

Patent metadata

Field	Value
Publication number	US-2016019673-A1
Application number	US-201414773283-A
Country	US
Kind code	A1
Filing date	Jan 8, 2014
Priority date	Mar 6, 2013
Publication date	Jan 21, 2016
Grant date	—

Abstract

A fingerprint image conversion device includes image conversion means 13 for acquiring a three-dimensional image of a finger, and converting the three-dimensional image into a two-dimensional image with a fingerprint portion of the finger being spread.

First claim

1 . A fingerprint image conversion device comprising
image conversion unit which acquires a three-dimensional image of a finger, and converting the three-dimensional image into a two-dimensional image with a fingerprint portion of the finger being spread.

2 . The fingerprint image conversion device according to claim 1 , wherein the image conversion unit sets a first axis in a longitudinal direction of the finger, sets a second axis orthogonal to the first axis, and extends the two-dimensional image in a direction of the second axis to shape the two-dimensional image into a two-dimensional image of a predetermined shape.

3 . The fingerprint image conversion device according to claim 2 , wherein the image conversion unit cuts the two-dimensional image substantially in parallel with the direction of the second axis to divide the two-dimensional image into a plurality of strip portions, sets an extension rate for each of the plurality of strip portions, and extends the strip portion so that a coordinate value in the direction of the second axis in the strip portion after the extension is a result of multiplying a coordinate value in the direction of the second axis in the strip portion before the extension by the extension rate.

4 . The fingerprint image conversion device according to claim 3 , wherein the image conversion unit sets a higher extension rate for a strip portion that is, in a direction to a fingertip, farther from a strip portion longest in the direction of the second axis.

5 . The fingerprint image conversion device according to claim 2 , wherein the image conversion unit shapes the two-dimensional image so that a side nearest a fingertip becomes to be concave.

6 . The fingerprint image conversion device according to claim 2 , wherein the image conversion unit converts the two-dimensional image into the two-dimensional image of the predetermined shape, when converting the three-dimensional image into the two-dimensional image with the fingerprint portion of the finger being spread.

7 . The fingerprint image conversion device according to claim 1 , comprising
unevenness image generation unit which shades the two-dimensional image based on a height of unevenness in a normal direction of the fingerprint portion.

8 . A fingerprint image conversion system comprising:
the fingerprint image conversion device according to claim 1 ; output unit which displays the two-dimensional image obtained by the conversion; and comparison unit which compares the two-dimensional image with a two-dimensional fingerprint image to be compared.

9 . A fingerprint image conversion method comprising
acquiring a three-dimensional image of a finger, and converting the three-dimensional image into a two-dimensional image with a fingerprint portion of the finger being spread.

10 . The fingerprint image conversion method according to claim 9 , comprising
setting a first axis in a longitudinal direction of the finger, setting a second axis orthogonal to the first axis, and extending the two-dimensional image in a direction of the second axis to shape the two-dimensional image into a two-dimensional image of a predetermined shape.

11 . A non-transitory computer readable information recording medium storing a fingerprint image conversion program that, when executed by a processor, performs a method for
acquiring a three-dimensional image of a finger, and converting the three-dimensional image into a two-dimensional image with a fingerprint portion of the finger being spread.

12 . The non-transitory computer readable information recording medium storing a fingerprint image conversion program according to claim 11 that, when executed by a processor, performs a method for
setting a first axis in a longitudinal direction of the finger, setting a second axis orthogonal to the first axis, and extending the two-dimensional image in a direction of the second axis to shape the two-dimensional image into a two-dimensional image of a predetermined shape.

13 . The fingerprint image conversion device according to claim 3 , wherein the image conversion unit shapes the two-dimensional image so that a side nearest a fingertip becomes to be concave.

14 . The fingerprint image conversion device according to claim 4 , wherein the image conversion unit shapes the two-dimensional image so that a side nearest a fingertip becomes to be concave.

15 . The fingerprint image conversion device according to claim 3 , wherein the image conversion unit converts the two-dimensional image into the two-dimensional image of the predetermined shape, when converting the three-dimensional image into the two-dimensional image with the fingerprint portion of the finger being spread.

16 . The fingerprint image conversion device according to claim 4 , wherein the image conversion unit converts the two-dimensional image into the two-dimensional image of the predetermined shape, when converting the three-dimensional image into the two-dimensional image with the fingerprint portion of the finger being spread.

17 . The fingerprint image conversion device according to claim 5 , wherein the image conversion unit converts the two-dimensional image into the two-dimensional image of the predetermined shape, when converting the three-dimensional image into the two-dimensional image with the fingerprint portion of the finger being spread.

18 . The fingerprint image conversion device according to claim 2 , comprising
unevenness image generation unit which shades the two-dimensional image based on a height of unevenness in a normal direction of the fingerprint portion.

19 . The fingerprint image conversion device according to claim 3 , comprising
unevenness image generation unit which shades the two-dimensional image based on a height of unevenness in a normal direction of the fingerprint portion.

20 . The fingerprint image conversion device according to claim 4 , comprising
unevenness image generation unit which shades the two-dimensional image based on a height of unevenness in a normal direction of the fingerprint portion.

Assignees

• Nec Corp

Inventors

• Sakamoto Shizuo

Classifications

• G06V40/1312 Primary

  direct reading, e.g. contactless acquisition · CPC title

• G06T2210/32

  Image data format · CPC title

• G06T3/0037 Primary

  Physics · mapped topic

• G06K9/00013

  Physics · mapped topic

• G06T2200/04

  involving 3D image data · CPC title