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JP-2026075071-A - A method and device for determining the number of partial palm prints to be acquired in order to reconstruct an entire palm print, and a corresponding acquisition method and system.

JP2026075071AJP 2026075071 AJP2026075071 AJP 2026075071AJP-2026075071-A

Abstract

[Problem] To provide a method and device for determining the number of partial palm prints to be acquired in order to reconstruct the entire palm print, as well as a corresponding acquisition method and system. [Solution] The present invention relates to a method for determining the number of palm print partial images acquired using a nipple print acquisition device, wherein the nipple print acquisition device comprises an acquisition area smaller in size than the area of the palm representing a group of individuals. [Selection Diagram] Figure 1

Inventors

  • トゥレット， オリヴィエ
  • カズダグリー， ローラン

Assignees

  • アイデミア パブリック セキュリティ フランス

Dates

Publication Date
20260507
Application Date
20251016
Priority Date
20241021

Claims (15)

  1. A method for determining (DET) the number of palm print partial images to be acquired using a nipple print acquisition device (1), wherein the nipple print acquisition device comprises an acquisition area (21) smaller than the area of the palm representing a group of individuals, and the method is implemented by a computer (3), comprising the following steps: a) Step (E1) to acquire an image of an individual's nipple print obtained using the acquisition device (1), b) A step (E2) of measuring at least one geometric dimension of the nipple print using the nipple print image, c) A step (E3) of estimating at least one geometric dimension of the individual's palm based on at least one geometric dimension of the nipple print, d) A method comprising step (E4) determining a number N of acquisitions of images I1 , ..., IN of the individual's palm necessary to cover the entire area of the palm, where each acquisition corresponds to one position P1 , ..., PN of the individual's palm on the acquisition area (21 ) of the acquisition device (2).
  2. The method according to claim 1, wherein the nipple print image includes at least one fingerprint of the individual, and in step c), the first geometric dimension of the individual's palm is the width of the palm, the width of the palm is estimated using a first interpolation function (f1) based on the measured geometric dimension of the nipple print, and the second geometric dimension of the individual's palm is the length of the palm, the length of the palm is estimated using a second interpolation function (f2) based on the measured geometric dimension of the nipple print.
  3. The method according to claim 2, wherein the first interpolation function is a function (f1) for interpolating the width of the palms of multiple individuals based on at least one geometric dimension of their fingerprints, and the second interpolation function (f2) is a function (f2) for interpolating the length of the palms of multiple individuals based on one length of their palms.
  4. The method according to claim 2, wherein the at least one geometric dimension of the fingerprint is selected from the width (A), length (L), or area (S) of the fingerprint, or a combination thereof.
  5. The method according to claim 1, wherein the nipple print image includes the interdigital portion of the palm of the individual, and in step b), the width of the interdigital portion is measured, and in step c), the width and length of the palm are estimated using a first interpolation function for interpolating the width of the palm and a second interpolation function for interpolating the length of the palm, respectively, based on the measured width of the interdigital portion.
  6. The method according to claim 1, wherein in step b), at least one distance between two nipple ridges is measured in the nipple print image taken in step a), and in step c), the width and length of the palm are estimated, respectively, using a first function (f3) for interpolating the width of the palm and a second function (f4) for interpolating the length of the palm, depending on the distance measured between the two nipple ridges.
  7. Step d) is the following substep: - A substep of comparing the at least one estimated geometric dimension of the palm with the geometric dimension of the acquisition area of the acquisition device, The method according to claim 1, comprising the substep of determining the position P1 , ..., PN for each acquisition of an image I1 , ..., IN of the individual's palm on the acquisition area of the acquisition device, based on the results of the comparison.
  8. The method according to claim 7, wherein, if the estimated width and estimated length are smaller than the geometric dimensions of the acquisition region (21) of the acquisition device (2), the number of image acquisitions N is a single image I1 associated with a position P1 centered on the acquisition region of the acquisition device.
  9. If either the estimated length or estimated width of the palm is greater than the geometric dimensions of the acquisition area (21) of the acquisition device (2), - Regarding length, the number N of image acquisitions is at least two images I1, I2 associated with a first position P1 corresponding to the upper part of the palm, preferably at least the upper half of the palm, and a second position P2 corresponding to the lower part of the palm, preferably at least the lower half of the palm, or - Regarding width, the number N of image acquisitions is at least two images I1, I2 associated with a first position P1 corresponding to the right half of the palm and a second position P2 corresponding to the left half of the palm, The method according to claim 7.
  10. The method according to claim 7, wherein if the estimated width and estimated length are greater than the geometric dimensions of the acquisition area (21) of the acquisition device, the number N of image acquisitions is at least four images I1, I2, I3, I4 associated with a first position P1 corresponding to the upper half of the palm, a second position P2 corresponding to the lower half of the palm, a third position P3 corresponding to the right half of the palm, and a fourth position P4 corresponding to the left half of the palm, respectively.
  11. A method for obtaining an image of the nipple prints across the entire palm, following these steps: e) A step (ACQ) of obtaining a number N of acquisitions of images I1, ..., IN of the individual's palm, necessary to cover the entire area of the palm, using a nipple print acquisition device (1) having an acquisition area (21) smaller in size than the area of the palm representing a group of individuals, wherein each acquisition corresponds to one position P1 , ..., PN of the individual's palm on the acquisition area ( 21 ) of the acquisition device (2), and the number is obtained by the method of claim 1. f) A step (VER) to verify that the acquired image covers the entire palm of the individual, g) If the acquired image does not cover the entire palm, the step of acquiring at least one corrected image (ACQS) at a given position, A method comprising the step (REC) of reconstructing the entire palm from the images obtained in step e) and optionally in step g).
  12. The verification (VER) described above involves the following steps: - The step of reconstructing the palm from the acquired image (E51), - A step (E52) of calculating the width and/or length of the reconstructed palm, The method according to claim 11, comprising the step (E53) of comparing the calculated width and/or the calculated length with a reference value.
  13. In step e), the acquired image includes at least one palm edge, and the verification (VER) is performed in the following steps: - The step of detecting the edge of the palm in the acquired image (E61), - The process includes the step (E62) of verifying the presence of all the edges of the palm, and if the edges of the palm are missing, at least one corrected image is obtained. The method according to claim 11.
  14. The following steps: - A step (E63) of calculating the width and/or length from the edge of the palm, The method according to claim 13, further comprising the step (E64) of comparing the calculated width and/or the calculated length with at least one reference value, wherein at least one corrected image is obtained in accordance with the result of the comparison.
  15. A nipple print acquisition device (1) comprising a sensor (2), wherein the sensor (2) comprises an acquisition area (21) smaller than the entire palm area of a group of individuals, and the device (1) comprises a computer (3) configured to implement the method according to any one of claims 1 to 14.

Description

This invention relates to the field of biometric imaging, and more particularly to palm print imaging. It is common practice to obtain fingerprints, which are more commonly known by the general term "papillary prints," encompassing both "fingerprints" and "palm prints." Fingerprints are patterns formed by the dermal ridges of the fingers, while palm prints are patterns formed by the dermal ridges of the palms. Dermal ridges are superficial grooves formed by dermal ridges on the palms, soles of the feet, and fingertips, arranged in lines or spirals. They are unique to each individual. The patterns they form constitute a biometric "identification card," thereby allowing for the identification of an individual. Taking fingerprints is common practice in various administrative procedures conducted by state agencies, and in work performed by law enforcement agencies in connection with suspects or defendants in the context of violations, crimes, offenses, or criminal investigations. It is known that complete palm prints can be acquired using devices with an acquisition area that allows for the acquisition of an individual's entire palm in a single acquisition, regardless of palm size. However, such devices are bulky and not very portable. In practice, smaller mobile devices are preferred, especially in the context of field activities, because they are more ergonomic. An example of a typical mobile device is one with an acquisition area whose dimensions conform to the "FAP60" standard (76 mm x 81 mm). However, the average palm width for men is 89 mm. Therefore, such a device cannot capture the entire palm print of the vast majority of individuals in a single acquisition. One solution is to obtain a partial palm print and then reconstruct the entire palm using image processing. (Patent Document 1) describes a method for reconstructing a palm from images such as images of partial palm prints with overlapping regions. Nevertheless, the completeness and accuracy of such reconstructions depend primarily on the extent of the palm that partial fingerprint images tend to allow during their assembly. However, it is common for the number of partial fingerprint images to be insufficient, and/or for these images not to cover all relevant areas of the palm. Faced with this problem, human operators using small acquisition devices to acquire partial palm prints of an individual with the aim of reconstructing the entire palm print often tend to unnecessarily increase the number of acquisitions, even if this does not guarantee that the entire palm is actually covered. As a result, time is wasted and operational efficiency decreases. European Patent Application Publication No. 4273815 NASA MAN-SYSTEMS STANDARDS-3 ANTHROPOMETRY AND BIOMECHANICS, Revision B, July 1995, Volume 1, Section 3Sharma et al. (2022). Is fingerprint density influenced by hand dimensions? Acta Biomed This invention makes it possible to improve the reconstruction of the entire palm print from partial palm prints by determining the number of partial palm prints to be acquired to cover the entire palm. In certain embodiments, the invention also makes it possible to reduce the risk of operator error by using a partial print acquisition sequence in which each acquisition corresponds to one specific position on the individual's palm relative to the acquisition area of the acquisition device. According to a first aspect of the present invention, a method is provided for determining the number of palm print partial images to be acquired using a nipple print acquisition device, wherein the nipple print acquisition device has an acquisition area smaller in size than the palm area representing a group of individuals, and the method is implemented by a computer, and consists of the following steps: a) The step of acquiring an image of an individual's nipple print obtained using the acquisition device, b) Using a nipple print image, the step of measuring at least one geometric dimension of the nipple print, c) For example, the step of estimating at least one geometric dimension of an individual's palm from at least one geometric dimension of a nipple print, preferably using one or more interpolation functions calculated based on statistics of various measurements of multiple individuals, d) A step of determining the number N of acquisitions of an individual's palm I1 , ..., IN required to cover the entire area of the palm, from at least one estimated geometric dimension of the individual's palm, wherein each acquisition corresponds to one position P1 , ..., PN of the individual's palm on the acquisition area of the acquisition device. The present invention is advantageously complemented by the following features, which can be implemented individually or in any technically possible combination thereof. - In step a), the nipple print image includes at least one fingerprint of the individual; in step c), the first geometric dimension of the individual's palm is the width of th