Method for contact-free detection of biometric data of biometric features by means of a detection device and device for contact-free detection of biometric data of biometric features

Abstract

The present disclosure relates to a method for contact-free detection of biometric data of biometric features (110), in particular fingerprints (110), by means of a detection device (1000), wherein the method comprises: positioning the biometric features (110), from which the biometric data are to be detected, in a recording volume (400) of the detection device (1000), illuminating the biometric features (110) inside the recording volume (400) by means of an illumination device (500), wherein the illumination of the biometric features (110) comprises at least one sequence (10) of images (10a, 10b) projected onto the biometric features (110), recording the biometric features (110) illuminated by the illumination device (500) on the basis of the at least one sequence (10) of projected images (10a, 10b) by means of an image recording device (600), aligning at least one recording of the recordings of the biometric features (110), which were recorded on the basis of the projected images of the at least one sequence (10) of projected images (10a, 10b), with a further recording of the recordings of the biometric features (110) on the basis of the at least one sequence (10) of projected images (10a, 10b), and calculating the biometric data on the basis of the at least one aligned recording of the biometric features (110).

Description

[0001] METHOD FOR CONTACTLESS COLLECTION OF BIOMETRIC DATA FROM

[0002] BIOMETRIC FEATURES BY MEANS OF A DETECTION DEVICE AND DEVICE FOR CONTACTLESS DETECTION OF BIOMETRIC DATA FROM BIOMETRIC FEATURES

[0003] Description

[0004] The present disclosure relates to a method for contactless capture of biometric data of biometric features, in particular fingerprints, by means of a capture device and a device for contactless capture of biometric data of biometric features, in particular fingerprints.

[0005] background

[0006] In addition to the well-known contact-based methods of capturing biometric data, contactless methods can also be used to capture biometric data from biometric characteristics such as people's fingerprints.

[0007] However, simply photographing the biometric features, for example, using diffuse lighting, is often insufficient for high-quality capture of biometric features such as fingerprints, as the resulting image information cannot clearly distinguish the ridges and valleys of the papillary lines. Therefore, it is advantageous to capture the biometric features in 3D.

[0008] However, with the contactless 3D capture of very fine structures such as a person's fingerprints, there is also the problem that when holding their hand or fingers over a corresponding capture device, the person tends to make small, random movements of the hand or individual fingers, such as trembling or individual twitches due to the tension or relaxation of the hand and arm muscles.

[0009] Since the 3D data calculation, which is based on recordings of biometric features using structured lighting, is based on a dataset of raw images captured sequentially, a way to compensate for these movements when the hand is held freely in space is necessary. This is necessary because movements change the orientation of objects relative to the lighting pattern / structure, which destroys the assignment of the recorded biometric features across the individual images and thus leads to inaccurate 3D data.

[0010] The alignment of the images to each other, however, is only possible to a limited extent, since the pattern / structure of the structured lighting itself is subject to movement between two images and thus has the greatest influence on the movement of the entire image information of the images.

[0011] In view of the disadvantages described above, it is an object of the present application, based on the known prior art, to provide an improved method for the contactless capture of biometric data of biometric features, in particular fingerprints, and a corresponding device.

[0012] Summary

[0013] The present disclosure relates to a method for contactless capture of biometric data of biometric features, in particular fingerprints, by means of a capture device and a device for contactless capture of biometric data of biometric features, in particular fingerprints.

[0014] In particular, to achieve the above-mentioned object, a method for contactless capture of biometric data from biometric features, in particular fingerprints, by means of a capture device according to claim 1 and a device for contactless capture of biometric data from biometric features, in particular fingerprints, according to claim 25 are proposed. The dependent claims relate to some exemplary preferred embodiments.

[0015] According to a first aspect, in some embodiments, a method for contactless capturing of biometric data from biometric features, in particular fingerprints, by means of a capturing device is proposed, wherein the method comprises: positioning the biometric features from which the biometric data are to be captured in a recording volume of the capturing device, illuminating the biometric features within the recording volume by means of an illumination device, wherein the illumination of the biometric features comprises at least one sequence of images projected onto the biometric features, capturing the biometric features illuminated by the illumination device on the basis of the at least one sequence of projected images by means of an image capturing device, aligning at least one image of the images of the biometric features,which were recorded on the basis of the projected images of the at least one sequence of projected images, compared to a further recording of the recordings of the biometric features based on the at least one sequence of projected images, and calculating the biometric data based on the at least one aligned recording of the biometric features.

[0016] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one sequence of projected images has at least one projected additional image which is different from the remaining projected images of the at least one sequence of projected images, wherein the method comprises: aligning at least one image of the images of the biometric features which were recorded on the basis of the projected images of the at least one sequence of projected images which are different from the projected additional image, with at least one image of the biometric features which was recorded on the basis of the at least one projected additional image, and calculating the biometric data on the basis of the at least one,recording of the biometric features based on the projected images different from the projected additional image, which is aligned with the recording based on the at least one projected additional image.

[0017] In some preferred embodiments, the method can be advantageously further developed in such a way that at least two images of the images of the biometric features that were recorded on the basis of the projected images of the at least one sequence of projected images that are different from the projected additional image are aligned with respect to the at least one image of the biometric features that was recorded on the basis of the at least one projected additional image, and the biometric data are calculated on the basis of the images of the biometric features that are aligned with respect to the image based on the at least one projected additional image on the basis of the projected images that are different from the projected additional image.

[0018] In some preferred embodiments, the method can be advantageously further developed such that the at least one projected additional image is illuminated to at least 90% of its projected image area, preferably to at least 95% of its projected image area, particularly preferably to be illuminated substantially over its entire surface.

[0019] In some preferred embodiments, the method can be advantageously further developed such that the unilluminated image areas of the at least one projected additional image are distributed over a substantial area of ​​the at least one projected additional image.

[0020] In some preferred embodiments, the method can be advantageously further developed in such a way that essentially at least the biometric features from which the biometric data are to be captured are completely illuminated by at least one illuminated image area of ​​the at least one projected additional image.

[0021] In some preferred embodiments, the method can be advantageously further developed such that different brightness values ​​are present within the illuminated image area of ​​the at least one projected additional image, or the illuminated image area of ​​the at least one projected additional image is substantially uniformly illuminated.

[0022] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one projected additional image has brightness values ​​in the range 30 - 500 lux, preferably 75 - 350 lux, particularly preferably 150 - 260 lux for the illuminated image areas.

[0023] In some preferred embodiments, the method can be advantageously further developed in such a way that the sequence of projected images has at least two structural images projected with structured light, preferably has at least four structural images projected with structured light, particularly preferably has at least ten structural images projected with structured light, which are different from the at least one additional image.

[0024] In some preferred embodiments, the method can be advantageously further developed such that each of the projected structural images of the sequence of projected images has a line grating, in particular a line grating as a sinusoidal light-dark sequence, wherein the line width of the line gratings differs within the sequence of projected images. In some preferred embodiments, the method can be advantageously further developed such that, within the sequence of projected images, the line gratings with wider line widths are arranged chronologically before the line gratings with narrower line widths, or, within the sequence of projected images, the line gratings with narrower line widths are arranged chronologically before the line gratings with wider line widths.

[0025] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one projected additional image is projected as the first image of the sequence of projected images, or the at least one projected additional image is projected as the last image of the sequence of projected images.

[0026] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one projected additional image is projected as the second image of the sequence of projected images, or the at least one projected additional image is projected as the penultimate image of the sequence of projected images.

[0027] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one projected additional image is projected as the third image of the sequence of projected images, or the at least one projected additional image is projected substantially in the middle of the sequence of projected images.

[0028] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one projected additional image within the sequence of projected images is arranged substantially adjacent to the structural images of the line grids with the narrowest line widths within the sequence of projected images.

[0029] In some preferred embodiments, the method can be advantageously further developed in such a way that, within the sequence of projected images, the at least one projected additional image is arranged in time immediately before the structural images with the narrowest line width of the line grid, or, within the sequence of projected images, the at least one projected additional image is arranged in time immediately after the structural images with the narrowest line width of the line grid.

[0030] In some preferred embodiments, the method can be advantageously further developed in such a way that, within the sequence of projected images, the at least one projected additional image is arranged substantially in the middle between the structural images with the narrowest line width of the line grid.

[0031] In some preferred embodiments, the method can be advantageously further developed in such a way that the images of the biometric features that were recorded on the basis of the projected structural images with the narrowest line grid are aligned with respect to the image of the biometric features based on the at least one projected additional image, and the aligned images of the biometric features based on the structural images with the narrowest line grid are used to calculate the biometric data of the recorded biometric features.

[0032] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one sequence of projected images is projected onto the area of ​​the biometric features within a time period of 100 milliseconds, preferably within 70 milliseconds, particularly preferably within 50 milliseconds.

[0033] In some preferred embodiments, the method can be advantageously further developed in such a way that, for the alignment, a pattern related to the biometric features is used within the recordings based on the projected structural images and within the recording based on the at least one projected additional image.

[0034] In some preferred embodiments, the method can be advantageously further developed in such a way that the pattern has structures of the biometric features, in particular finger lines or skin pores.

[0035] In some preferred embodiments, the method can be advantageously further developed in such a way that the at least one sequence of projected images is at least a sequence of substantially identical images, in particular at least a sequence of substantially identical structural images projected with structured light.

[0036] In some preferred embodiments, the method can be advantageously further developed such that calculating the biometric data comprises calculating the 3D information of the biometric data, in particular calculating the 3D information of the fingerprints. In some preferred embodiments, the method can be advantageously further developed such that the images of the at least one sequence of projected images comprise light with a wavelength of 420-490 nm, preferably 440-470 nm, particularly preferably 460 nm.

[0037] According to a second aspect, in some embodiments, a device for the contactless capture of biometric data from biometric features, in particular fingerprints, is proposed, wherein the device comprises: a recording volume in which the biometric features from which the biometric data are to be captured can be positioned, an illumination device for illuminating the biometric features within the recording volume, wherein the illumination device is configured to project at least one sequence of images onto the biometric features for illuminating the biometric features, an image recording device for recording the biometric features illuminated by the illumination device on the basis of the at least one sequence of projected images, and a computing unit configured to process at least one recording of the recordings of the biometric features,which were recorded on the basis of the projected images of the at least one sequence of projected images, with respect to a further recording of the recordings of the biometric features on the basis of the at least one sequence of projected images, and to calculate the biometric data on the basis of the at least one aligned recording of the biometric features.

[0038] Further aspects and their advantages as well as advantages and more specific embodiments of the aspects and features described above are described in the following, but in no way limiting, descriptions and explanations of the attached figures.

[0039] Short description of the characters

[0040] Fig. 1 shows an exemplary flowchart of a method for contactless capture of biometric data of biometric features,

[0041] Fig. 2 shows an exemplary flowchart of another method for contactless capture of biometric data of biometric features, Fig. 3 shows an exemplary representation of referencing and aligning several images of biometric features with respect to a further or additional image of the biometric features,

[0042] Fig. 4 shows an exemplary representation of various series of exemplary structured illuminated images of biometric features with an exemplary non-structured illuminated image of the biometric features based on a sequence of projected images,

[0043] Fig. 5 shows an exemplary representation of various non-structured illumination images for illuminating the biometric features to be recorded or only very weakly structured illumination images for illuminating the biometric features to be recorded,

[0044] Fig. 6 shows an exemplary representation of a device for contactless capture of biometric data of biometric features.

[0045] Detailed description of the figures and preferred embodiments

[0046] Examples and embodiments of the present disclosure are described in detail below with reference to the accompanying figures. Identical or similar elements in the figures may be designated by the same reference numerals, but sometimes also by different reference numerals.

[0047] It should be emphasized, however, that the subject matter of the present disclosure is in no way limited or restricted to the exemplary embodiments and their embodiment features described below, but further comprises modifications of the exemplary embodiments, in particular those which are encompassed by modifications of the features of the described examples or by combination of one or more of the features of the described examples within the scope of protection of the independent claims.

[0048] Fig. 1 shows an exemplary flowchart of a method for contactless capture of biometric data of biometric features 110, in particular fingerprints 110, by means of a capture device 1000, wherein reference is made to Fig. 6 for all features relating to the capture device 1000 and biometric features 110 or fingerprints 110. In this case, first, in a step S101, the biometric data to be captured

[0049] Features 110, such as fingerprints 110 of a hand 100, in a

[0050] Recording volume 400 of a detection device 1000 can be positioned contactlessly.

[0051] The recording volume 400 of the detection device 1000 can, for example, be an area above an opening of the detection device 1000, which is covered, for example, by a light-permeable element 410 (for example a glass plate that protects against dust and dirt), in which, for example, the hand 100 as the carrier of the biometric features 110 to be recorded is held contactlessly (without physical contact with the detection device 1000).

[0052] In addition, for example, the detection device 1000 can be configured to provide appropriate feedback about the current hand position and / or about a target position of the hand 100, so that the hand 100 or the biometric features 110 can be positioned within a certain tolerance range in the recording volume 400 for recording the biometric features 110.

[0053] In a further step S102, the biometric features 110 to be recorded can now be illuminated within the recording volume 400 of the detection device 1000 by an illumination device 500. Images 10a, 10b, for example, are projected by the illumination device 500 (e.g., configured as a projector 500) onto the areas of the biometric features 110 to be recorded.

[0054] In particular, the illumination device 500 projects at least one sequence 10 of images 10a, 10b onto the areas of the biometric features 110 to be recorded. The at least one sequence 10 of projected images 10a, 10b can be configured very differently, for example, in the number of images 10a, 10b. For example, the sequence 10 can comprise three images 10a, 10b, preferably five images 10a, 10b (or seven images 10a, 10b), and particularly preferably eleven images 10a, 10b (or nine images 10a, 10b). It should be noted at this point that the number of images in the at least one sequence 10 of images 10a, 10b can comprise even more images.

[0055] Furthermore, it may be advantageous if the at least one sequence 10 of images 10a, 10b projected onto the biometric features 110 to be recorded comprises at least one structured image 10a (structured illumination), but preferably a plurality of structured images 10a. These can be advantageously used, for example, to capture the topology, in particular the heights and depths of the structures of the biometric features 110. The more accurately the topology of the biometric features 110 can be captured, the better the quality of the biometric data subsequently calculated from it, in particular 3D biometric data of the biometric features 110.

[0056] Suitable structures for the projected structural images 10a include, for example, line grids, in particular line grids such as sinusoidal light-dark sequences, in which the lines (dark areas) and / or the intermediate areas (light or illuminated areas) have essentially the same width. Furthermore, the line width can change between the individual projected structural images 10a within the sequence 10 of projected images 10a, 10b, and thus, while the area of ​​the projected structural image 10a remains constant, the number of lines within the respective structural image 10a.

[0057] An example for the at least one sequence 10 of projected images 10a, 10b can be that initially the structural images 10a with a larger (largest) / wider (widest) line width are arranged in the sequence 10 and the line width decreases as the sequence 10 of projected images 10a, 10b progresses, so that the structural images 10a with the line grids of the wider line width are arranged chronologically before the structural images 10a with the line grids of the narrower line width within the sequence 10 of images 10a, 10b or are projected onto the biometric features 110.

[0058] In this context, however, it can of course also be advantageous that the structural images 10a with a smaller (smallest) / narrower (narrowest) line width are initially arranged in the sequence 10 and that the line width increases as the sequence 10 of projected images 10a, 10b progresses, so that the structural images 10a with the line grids of the narrower line width are arranged chronologically before the structural images 10a with the line grids of the wider line width within the sequence 10 of images 10a, 10b or are projected onto the biometric features 110.

[0059] Furthermore, the structural images 10a within the at least one sequence 10 of projected images 10a, 10b, which have essentially the same line width or the same line grid, can have a slight shift in the position of the lines or the line grid, in particular orthogonal to the line direction (for example a phase shift in a sinusoidal light-dark sequence). This shift can, for example, be continued from each structural image 10a of one line width of the line grid to the next structural image 10a of the same line width of the line grid, so that, for example, within the at least one sequence 10 of projected images 10a, 10b, for example, there are at least four structural images 10a with the same line width of the line grid, but each of these four structural images 10a of the same line width has an offset / shift ora phase shift of the line grating relative to the other three structural images 10a. It should be noted at this point that the number of structural images 10a with the same line width of the line grating can also be smaller (e.g., two or three) or larger (e.g., six, eight, etc.).

[0060] By shifting the phase or shifting the line grid within the respective structural image 10a, the accuracy of the biometric features 110 to be captured can be increased and, on the other hand, the biometric features 110 can be captured completely.

[0061] It should also be noted at this point that the illumination of the biometric features 110 to be recorded can be carried out by multiple sequences 10 of projected images 10a, 10b, for example, ten to one hundred times the sequence 10 of projected images 10a, 10b, or the sequence 10 of projected images 10a, 10b is repeated until the biometric features 110 (for example of one hand 100 or both hands) have been recorded.

[0062] In a further step S103, the areas of the biometric features 110 illuminated by the illumination device 500 can now be recorded by an image recording device 600. For this purpose, a multi-row or two-dimensional light sensor / light detector (such as a high-resolution camera with, for example, 0.3 megapixels or up to 50 megapixels, with a CMOS sensor / Active Pixel Sensor (APS) or CCD sensor) can be used to image or photographically record the illuminated biometric features 110.

[0063] A further step S104 can now be performed, in which the biometric features 110 recorded by the image recording device 600, or at least one recording of the biometric features 110, is aligned with another recording of the recordings of the biometric features 110 based on the at least one sequence 10 of projected images 10a, 10b. For example, a pattern related to the biometric features 110 can be used to align the recorded biometric features 110. This pattern can include, for example, finger lines and / or skin pores (and / or scars and / or wrinkles) as reference points or reference structures in the recordings of the biometric features 110 based on the at least one sequence 10 of images 10a, 10b.

[0064] It should be noted at this point that, for example, preferably at least two images of the biometric features 110, particularly preferably at least four (or six or eight etc.) images of the biometric features 110, or all or all images of the biometric features 110 can be aligned, in particular aligned with one another.

[0065] Furthermore, the alignment of the recordings of the biometric features 110 can advantageously be configured such that, in the case of multiple sequences 10 of projected images 10a, 10b, only the recordings of the biometric features 110 that were recorded within a sequence 10 of the multiple sequences 10 are aligned. This advantageously prevents excessively large time intervals between the individual recordings from which the biometric data, in particular 3D biometric data, are to be calculated, which also prevents subsequent "stitching" of the biometric features recorded at comparatively significantly different times.

[0066] In addition, the biometric features 110 (for example, structures or partial structures of the fingerprints) themselves can be used as a pattern for aligning the recorded biometric features 110 (see, for example, Fig. 3).

[0067] This can be particularly advantageous because, due to the contactless holding of the exemplary hand 100 as the carrier of the biometric features 110 to be recorded within the recording volume 400 of the detection device 1000, a movement of the hand 100 cannot be prevented. In particular, smaller movements that cannot be controlled by humans (for example, trembling or twitching of the hand or individual fingers due to tension and / or relaxation of the hand or arm muscles) can have a significant impact on the quality of the biometric data, in particular the 3D data or 3D biometric data that can be obtained from the recordings of the biometric data 110.

[0068] In addition, when using structured illumination, the problem may arise that, in addition to the movement of the hand 100 relative to the detection device 1000 or the illumination and image recording device 500, 600, the displacement of the line grid from one structural image 10a to the next structural image 10a within the at least one sequence 10 of projected images 10a, 10b must be compensated / calculated out, which is, however, possible by aligning the recordings of the biometric features 110.

[0069] In a further step S105, the biometric data, in particular 3D biometric data, can now be calculated on the basis of the at least one aligned recording of the biometric features 110 (in particular on the basis of the recordings of the biometric features 110 aligned with one another) and can be provided, for example, for further processing such as storage, comparison with already known or existing recordings and / or biometric data.

[0070] It should be noted at this point that, for example, the structural images 10a can comprise light with a wavelength of 420-490 nm, preferably 440-470 nm, particularly preferably 460 nm. This wavelength of the projected light can be advantageous for recording the biometric features 110 (particularly advantageous for higher resolution of the recorded biometric features 110) as well as advantageous for the subsequent alignment of the images of the biometric features 110 due to the scattering characteristics of the skin.

[0071] By means of the described method, the (uncontrolled) movement of the hand as well as the movement (shifting / phase shifting) of the structured illumination between the individual recordings of the biometric features 110 can be advantageously compensated and the influence of these movements of the biometric features 110 on the quality of the biometric data, in particular the 3D biometric data, can thereby be significantly reduced.

[0072] Fig. 2 shows an exemplary flow chart of a further method for the contactless capture of biometric data of biometric features 110, in particular fingerprints 110, by means of a capture device 1000, wherein reference is also made to Fig. 6 for all features relating to the capture device 1000 and biometric features 110 or fingerprints 110.

[0073] In this case, steps S201 and S202 can be carried out essentially as described in steps S101 and S102 in Fig. 1. It should also be noted that the exemplary method according to Fig. 2 can represent a further development of the exemplary method according to Fig. 1.

[0074] However, in step S202, in contrast to step S102 according to Fig. 1, the at least one sequence 10 of images 10a, 10b is changed in that the at least one sequence 10 of images 10a, 10b now further comprises at least one additional image 10b which is different from the remaining images 10a (such as the structural images 10a) projected by the illumination device 500 onto the biometric features 110 to be recorded.

[0075] In this case, the image area of ​​the at least one additional image 10b can essentially exclusively have brightness areas (also referred to as a "bright image" or "flat image") or the image area of ​​the at least one additional image 10b, in contrast to the structured images 10a, essentially has no dark areas (areas that are not illuminated).

[0076] Furthermore, the at least one projected additional image 10b can be illuminated to at least 90% of its projected image area, preferably to at least 95% of its projected image area, and particularly preferably to be illuminated substantially over its entire surface (see, for example, Fig. 5 (a) and (b)). The unilluminated areas / unilluminated image areas of the additional image 10b can comprise a very small proportion of the additional image 10b projected onto the biometric features. If unilluminated image areas / image regions are present, the unilluminated image areas of the at least one projected additional image 10b can be distributed over a substantial area (for example, at least 50%, in particular at least 75% of the image area of ​​the at least one projected additional image 10b) of the at least one projected additional image 10b (see, for example, Fig. 5 (c) and (d)).

[0077] Furthermore, in this context, the additional image 10b may have very fine dark areas distributed essentially over the entire image area of ​​the additional image 10b (see, for example, Fig. 5 (c) and (d)). These fine dark areas may, for example, be formed as fine lines and be reflected by a surface of the biometric features 110 (for example, the skin of the hand 100) in such a way that these fine dark areas have essentially disappeared in the images of the biometric features 110 and are captured as illuminated, possibly only weakly illuminated, areas by the image capture device 600 of the capture apparatus 1000.

[0078] Furthermore, it may be possible for the at least one additional image 10b to substantially completely illuminate at least the biometric features 110 from which the biometric data are to be captured through the illuminated image area of ​​the at least one projected additional image 10b.

[0079] Furthermore, the illuminated image areas of the at least one additional image 10b can have different brightness values. In particular, the brightness values ​​can be in the range of 30–500 lux, preferably 75–350 lux, and particularly preferably 150–260 lux. A single illuminated image area of ​​the at least one additional image 10b can also have the different brightness values ​​simultaneously. Furthermore, the illuminated regions of the structural images 10a can have the aforementioned brightness values.

[0080] Now, in step S202, the biometric features 110 to be recorded can be illuminated by the illumination device 500 within the recording volume 400 of the detection device 1000 by the at least one sequence 10 of images 10a, 10b, for example comprising at least two structural images 10a, preferably at least four structural images 10a, particularly preferably at least ten structural images 10a and the at least one additional image 10b.

[0081] For example, the at least one projected additional image 10b can be projected onto the biometric features 110 as the first image of the sequence 10 of projected images 10a, 10b, or the at least one projected additional image 10b can be projected onto the biometric features 110 as the last image of the sequence 10 of projected images 10a, 10b.

[0082] For example, it may also be the case that the at least one projected additional image 10b is projected onto the biometric features 110 as the second image of the sequence 10 of projected images 10a, 10b, or that the at least one projected additional image 10b is projected onto the biometric features 110 as the penultimate image of the sequence 10 of projected images 10a, 10b.

[0083] Furthermore, the at least one sequence 10 of projected images 10a, 10b can also be designed such that the at least one projected additional image 10b is projected onto the biometric features 110 as the third image of the sequence 10 of projected images 10a, 10b, or the at least one projected additional image 10b is projected onto the biometric features 110 substantially in the middle of the sequence 10 of projected images 10a, 10b.

[0084] However, it can also be advantageous if the at least one projected additional image 10b within the sequence 10 of projected images 10a, 10b is arranged substantially adjacent to the structural images 10a of the line grids with the narrowest line widths within the sequence 10 of projected images 10a, 10b.

[0085] This can be advantageous because the images of the biometric features 110 that were recorded on the basis of the projected structural images 10a with the narrowest line grid are aligned with respect to the image of the biometric features 110 based on the at least one projected additional image 10b, and the aligned images of the biometric features 110 based on the structural images 10a with the narrowest line grid can be advantageously used to calculate the biometric data of the recorded biometric features 110.

[0086] This ensures, for example, that the individual recordings of the biometric features 110 based on the structural images 10a and the recording of the biometric features 110 based on the additional image 10b are temporally related to one another, in particular that there are very short time intervals between the individual recordings, so that the movement of the hand 100 or the biometric features 110 can also only take place to a very small extent within the thus very short period of time.

[0087] In this case, the additional image 10b can also be arranged at the beginning or immediately before the structural images 10a with the narrowest line width within the at least one sequence 10 of projected images 10a, 10b, or the additional image 10b can be arranged at the end or immediately after the structural images 10a with the narrowest line width within the at least one sequence 10 of projected images 10a, 10b, or the additional image 10b can be arranged substantially in the middle between the structural images 10a with the narrowest line width within the at least one sequence 10 of projected images 10a, 10b (see, for example, Fig. 4).

[0088] In addition, for example, the at least one additional image 10b, like the structural images 10a, can also have light of the wavelength of 420 - 490 nm, preferably 440 - 470 nm, particularly preferably 460 nm, with the advantages already described.

[0089] It should also be pointed out again at this point that the illumination of the biometric features 110 to be recorded can be carried out by multiple sequences 10 of projected images 10a, 10b, for example, ten to one hundred times the sequence 10 of projected images 10a, 10b, or the sequence 10 of projected images 10a, 10b is repeated until the biometric features 110 (for example of one hand 100 or both hands) have been recorded.

[0090] Which of the images of the biometric features 110 recorded by the image recording unit 600 are ultimately used to calculate the biometric data, in particular 3D biometric data, can depend, for example, on the movement (e.g., trembling) of the hand or the biometric features 110 to be recorded. For example, it can be advantageous if the movement of the hand or the biometric features 110 to be recorded is detected during the recording of the biometric features 110 and evaluated to determine which sequence 10 of projected images 10a, 10b had the least movement, and then the corresponding images of the biometric features 110 from this sequence 10 of projected images 10a, 10b are used for the subsequent calculation of the biometric data (in particular 3D biometric data). This allows, for example, the quality of the image information for the 3D data calculation to be further optimized.

[0091] Now, in step S203, as in step S103 according to Fig. 1, the areas of the biometric features 110 illuminated by the illumination device 500 can be imaged or photographically recorded by the image recording device 600, wherein for this purpose, for example, a multi-line or two-dimensional light sensor / light detector (such as a high-resolution camera with, for example, 0.3 megapixels or up to 50 megapixels, with a CMOS sensor / APS or CCD sensor) can be used.

[0092] In a further step S204, similar to step S104 of Fig. 1, an alignment of at least one image of the images of the biometric features 110, which were recorded on the basis of the projected images (for example structural images 10a) of the at least one sequence 10 of projected images 10a, 10b that are different from the projected additional image 10b, is carried out with respect to at least one image of the biometric features 110 that was recorded on the basis of the at least one projected additional image 10b.

[0093] For this purpose, for example, as already described, the images or at least one of the images of the biometric features 110 based on the structural images 10a can be aligned with the narrowest line width compared to the image of the biometric features 110 based on the at least one additional image 10b, since the images of the biometric features 110 based on these structural images 10a can have the highest information content for the later calculation of the biometric data, in particular the 3D biometric data.

[0094] It should be mentioned at this point that, for example, at least two images of the images of the biometric features 110 based on the structural images 10a can be aligned with respect to the image of the biometric features 110 based on the at least one additional image 10b, or, for example, at least four (or six or eight etc.) images of the images of the biometric features 110 based on the structural images 10a can be aligned with respect to the image of the biometric features 110 based on the at least one additional image 10b.

[0095] In this case too, for example, a pattern that is related to the biometric features 110 can be used for the alignment of the recorded biometric features 110, wherein this pattern can have, for example, finger lines and / or skin pores (and / or scars and / or wrinkles) as reference points or reference structures in the recordings of the biometric features 110 based on the at least one sequence 10 of projected images 10a, 10b.

[0096] In addition, the biometric features 110 (for example structures or partial structures of the fingerprints) themselves can be used as a pattern for aligning the recorded biometric features 110 (see also Fig. 3, for example).

[0097] Now, in step S205, the biometric data can be calculated again on the basis of the at least one recording of the biometric features 110, which is aligned with respect to the recording based on the at least one projected additional image 10b, on the basis of the projected images (for example, structural images 10a) different from the projected additional image 10b, wherein, as already described, in particular the recordings of the biometric features 110 based on the structural images 10a with the narrowest line width of the line grid can be used for the calculation of the biometric data.

[0098] In addition to the already known advantages of compensating for (uncontrolled) movements of the hand as well as movements (shifts / phase shifts) of the structured illumination between the individual recordings of the biometric features 110, the described method can also be used to very reliably align the recorded biometric features 110 using at least one additional image 10b, thereby significantly further increasing the quality of the image data required for calculating the biometric data (in particular 3D biometric data).

[0099] Furthermore, it may be advantageous if at least two (or more) recordings of the biometric features 110 are aligned and used for the later calculation of the biometric data, in particular the 3D biometric data, since these, if the individual recordings have, for example, a phase shift of the line grids of their projected structural images 10a, together have a significantly higher image information content than a single recording of the biometric features 110, and this higher image information content can be advantageous in particular for the calculation of the biometric data, in particular the 3D biometric data.

[0100] Fig. 3 shows an exemplary representation of referencing and aligning several images of biometric features 110 with respect to a further or additional image of the biometric features 110.

[0101] In the upper area of ​​Fig. 3, an exemplary sequence 10 of projected images 10a, 10b can be seen, wherein initially only the representations of the structural images 10a within the sequence 10 are shown and the at least one additional image 10b is shown in the lower area of ​​Fig. 3.

[0102] In the representation of the exemplary sequence 10 of projected images 10a, 10b, it is initially recognizable how, for example, the line grid of the structural images 10a changes within the sequence 10, wherein it is shown here by way of example that the line width of the line grid in the first structural image 10a (see representation (a) of Fig. 3) has the wider or the widest line width within the sequence 10. This line width or the line grid can now change as the sequence 10 of projected images 10a, 10b progresses, for example, here reducing the line width (see representation (e) of Fig. 3) or increasing the number of lines while keeping the image area of ​​the projected structural images 10a constant.

[0103] At the end of the exemplary sequence 10 of projected images 10a, 10b, the structural images 10a with the narrower or narrowest line widths of the line grid are now arranged (see illustrations (v) to (y) of Fig. 3 for this purpose), wherein the additional image 10b can advantageously be arranged adjacent to these structural images 10a. In this example, the additional image 10b is arranged chronologically after the exemplary four structural images 10a with the narrowest line width (recognizable from illustration (z) of Fig. 3; wherein illustration (z) of Fig. 3 shows the recording of the biometric features 110 based on the additional image 10b, the additional image 10b here being essentially fully illuminated by way of example and thus exemplarily not having a line grid, as is the case in illustrations (v) to (y) of Fig. 3).The at least one additional image 10b can, of course, also be arranged at any other location within the sequence 10 of the projected images 10a, 10b, wherein it is advantageous if the at least one additional image 10b is arranged at least substantially adjacent to the structural images 10a, whose recordings of the biometric features 11 are later to be aligned with the recording of the biometric features 110 on the basis of the at least one additional image 10b (see also Fig. 4 as an example).

[0104] In the middle area of ​​Fig. 3, it is also shown by way of example how the biometric features to be recorded, here symbolically represented as a fingerprint 110, move within the images (for example, due to the described possible hand movements when holding the hand 100 into the recording volume 400 of the detection device 1000), as is shown in the upper row of figures (v) to (y) initially without the line grid of the projected structural images 10a. Furthermore, it is shown how the projected structural image 10a with the narrowest line width shifts from image to image (here, by way of example, representation (v) to representation (y) of Fig. 3) and also relative to the biometric features 110 to be recorded (shift / phase shift of the line grid within the projected structural image 10a), as is shown by way of example in the lower row of figures (v) to (y).

[0105] For reasons of the movement of the hand 100 or the biometric features 110 to be recorded on the one hand and the additional movement of the line grid within the projected structural images 10a on the other hand, it can be extremely advantageous to provide at least one additional image 10b (see illustration (z) of Fig. 3) within the sequence 10 of projected images 10a, 10b in order to correct or compensate for these movements for the detection of the biometric features 110.

[0106] Due to the recording of the biometric features 110 on the basis of the at least one additional image 10b (here representation (z) of Fig. 3), the remaining recordings of the biometric features 110, in particular the recordings based on the line grids with the narrowest line width, can now be aligned with the recording based on the at least one additional image 10b (see, for example, the representation (v)+(w)+(x)+(y)+(z) of Fig. 3, wherein for better recognition the line grids from the representations (v) to (y) of Fig.

[0107] 3 were omitted).

[0108] For the alignment itself, as already described, patterns within the images can be used, sometimes even parts of the structure of the biometric features 110 to be recorded or, for example, other patterns / structures, such as finger lines and / or skin pores and / or scars and / or wrinkles, etc.

[0109] Fig. 4 shows an exemplary representation of various series of exemplary structured illuminated images of biometric features 110 with an exemplary non-structured illuminated image of the biometric features 110 based on a sequence 10 of projected images 10a, 10b.

[0110] For this purpose, four images of the biometric features 110 with the narrowest line widths of the line grid are always shown as an example, as well as one image of the biometric features 110 with a very coarse grid or with very wide lines, whereby this image is always arranged at the beginning of the series of images, and one image of the biometric features 110 based on the at least one additional image 10b, the possible positions of which will be described below as an example.

[0111] In this case, for example, as shown in the row according to illustration (A) of Fig. 4, the at least one additional image 10b for recording the biometric features 110 can be arranged at the beginning or immediately before the structural images 10a with the narrowest line width of the line grid for recording the biometric features 110, so that the image (w) based on the structural image 10a is immediately adjacent to the image (v) based on the at least one additional image 10b and the image (z) based on the structural image 10a is somewhat spaced from the image (v) based on the at least one additional image 10b, but is substantially adjacent to the image (v) based on the at least one additional image 10b.

[0112] In a further exemplary row according to illustration (B) of Fig. 4, however, the at least one additional image 10b can now also be arranged at the end or immediately after the structural images 10a with the narrowest line width of the line grid for recording the biometric features 110, so that the image (y) based on the structural image 10a is immediately adjacent to the image (z) based on the at least one additional image 10b and the image (v) based on the structural image 10a is somewhat spaced from the image (z) based on the at least one additional image 10b, but is essentially adjacent to the image (z) based on the at least one additional image 10b.

[0113] In a further exemplary row according to illustration (C) of Fig. 4, the at least one additional image 10b can be arranged substantially in the middle or between the structural images 10a with the narrowest line width of the line grid for recording the biometric features 110, so that the images (w) and (y) based on the structural image 10a are immediately adjacent to the image (x) based on the at least one additional image 10b and the images (v) and (z) based on the structural image 10a are somewhat spaced from the image (z) based on the at least one additional image 10b, but these images are also substantially adjacent to the image (x) based on the at least one additional image 10b.

[0114] Advantageously, the arrangement of the recordings according to illustration (C) makes it possible for no recording based on the structural image 10a to be further away from the recording based on the at least one additional image 10b than two recordings, and additionally for two of the recordings based on the structural image 10a to be directly adjacent to the recording based on the at least one additional image 10b. This advantageously further reduces the influence of the movement of the hand or the biometric features to be recorded on the quality of the image information for the subsequent calculation of the biometric data, in particular 3D biometric data.

[0115] However, all three series of images of the biometric features 110 shown as examples have the advantage that the images based on the structural images 10a with the narrowest line width of the line grid, which are to be aligned as an example with respect to the image of the biometric features 110 based on the at least one additional image 10b, are substantially adjacent to the image of the biometric features 110 based on the at least one additional image 10b and thus, conversely, the structural images 10a with the narrowest line width of the line grid are arranged substantially adjacent to the at least one additional image 10b within the sequence 10.

[0116] In order to further minimize the influence of the movement of the hand 100 or the biometric features 110 to be recorded, it may be advantageous to keep the time span (shown in Fig. 4 as the time span t from the first recording (a) to the last recording (z)) of the sequence 10 of projected images 10a, 10b as short as possible. For example, the at least one sequence 10 of projected images 10a, 10b can be projected onto the area of ​​the biometric features 110 within a time span of 100 milliseconds, preferably within 70 milliseconds, and particularly preferably within 50 milliseconds, and the biometric features 110 can be recorded accordingly.

[0117] It should be noted at this point that the arrangement of the structural images 10a with the narrowest line widths of the line grids can also be arranged, for example, in the middle or at the beginning of the sequence 10 of the projected images 10a, 10b, even if these possibilities are not shown in Fig. 4.

[0118] Fig. 5 shows an exemplary representation of various non-structured illumination images 10b for illuminating the biometric features 110 to be recorded or only very weakly structured illumination images 10b for illuminating the biometric features 110 to be recorded.

[0119] In illustration (a) of Fig. 5, an essentially fully illuminated image 10b (for example, additional image 10b) is shown by way of example for projection onto the biometric features 110 to be recorded (for example, by the illumination device 500), wherein different brightness values ​​can be present within this fully illuminated image 10b (for example, brightness values ​​in the range 30 - 500 lux, preferably 75 - 350 lux, particularly preferably 150 - 260 lux; the different brightness values ​​are represented here by way of example by oblique hatching, wherein the hatching with less distance between the lines is intended to represent lower brightness values ​​than the hatching with wider distance between the lines).

[0120] In contrast, the illustration (b) of Fig. 5 shows, by way of example, an essentially uniformly illuminated image 10b (shown as uniform oblique hatching) as an exemplary additional image 10b for projection onto the biometric features 110, for example by the illumination device 500 (for example designed as a projector 500).

[0121] The representations (c) and (d) of Fig. 5 essentially show images 10b for the at least one projected additional image 10b, in which at least 90% of the projected image area is illuminated, preferably at least 95% of the projected image area is illuminated. The unilluminated image areas are shown as vertical lines, wherein these vertical lines have illuminated image regions between them. In particular, the unilluminated image areas of the at least one projected additional image 10b shown in representation (d) of Fig. 5 are distributed, for example, over a substantial area (for example, at least 50%, in particular at least 75% of the image area of ​​the at least one projected additional image 10b) of the at least one projected additional image 10b. In contrast, in representation (c), the unilluminated image areas of the additional image 10b are distributed essentially at the edge of the additional image 10b.

[0122] Fig. 6 shows an exemplary representation of a device 1000 for contactless capture of biometric data from biometric features 110.

[0123] In this case, the device 1000 / detection device 1000 can have a recording volume 400 in which the biometric features 110 (for example fingerprints 110 of a hand 100) from which the biometric data are to be recorded can be positioned, in particular positioned contactlessly.

[0124] The recording volume 400 of the detection device 1000 can, for example, be an area above a simple opening of the detection device 1000, which is covered, for example, by a light-permeable element 410 (for example a glass plate that protects against dust and dirt), into which, for example, the hand 100 as the carrier of the biometric features 110 to be recorded is held contactlessly.

[0125] In addition, the detection device 1000 can have an illumination device 500 for illuminating the biometric features 110 within the recording volume 400, wherein the illumination device 500 is configured to project at least one sequence 10 of images 10a, 10b onto the biometric features 110 for illuminating the biometric features 110.

[0126] In this case, the illumination device 500 can be designed as a projector 500 which projects the various images (such as structural images 10a of various line grids or line widths of the line grids and the at least one additional image 10b) of the at least one sequence 10 of projected images 10a, 10b onto the biometric features 110 to be recorded within, for example, 100 milliseconds, 70 milliseconds or 50 milliseconds.

[0127] Furthermore, the detection device 1000 can have an image recording device 600 for recording the biometric features 110 illuminated by the illumination device 500 based on the at least one sequence 10 of projected images 10a, 10b. The image recording device 600 can be configured, for example, as a camera 600 with, for example, a resolution of 0.3 megapixels up to 50 megapixels, wherein the image recording device 600 / camera 600 can further have at least one multi-row or two-dimensional CMOS sensor (or APS) or CCD sensor.

[0128] Furthermore, the detection device 1000 can have a computing unit 700 which is configured to align at least one of the images of the biometric features 110, which were recorded on the basis of the projected images 10a, 10b of the at least one sequence 10 of projected images 10a, 10b, with a further image of the images of the biometric features 110 based on the at least one sequence 10 of projected images 10a, 10b.

[0129] Furthermore, the computing unit 700 can be configured to calculate the biometric data, in particular the 3D biometric data, based on the at least one aligned recording of the biometric features 110 (aligned with respect to another recording of the biometric features 110 (according to Fig. 1) or with respect to the recording based on the additional image 10b (according to Fig. 2)) and thereby make it possible to store the captured or calculated biometric data for further use, for example, or to compare it with already known biometric data, etc.

[0130] Furthermore, the computing unit 700 can be configured to control all devices such as, for example, the illumination device 500 (and thus the sequence 10 of the projected images 10a, 10b) and / or the image recording device 600 (and thus the recording of the biometric features 110) of the detection device 1000.

[0131] In addition, the detection device 1000 can, for example, be configured to provide feedback about the current hand position and / or about a target position of the hand 100 within the recording volume 400, so that the hand 100 or the biometric features 110 can be positioned within a certain tolerance range in the recording volume 400 for recording the biometric features 110.

[0132] It should be noted that only examples or exemplary embodiments of the present disclosure, as well as technical advantages, have been described above in detail with reference to the accompanying figures. However, the present disclosure is in no way limited or restricted to the exemplary embodiments described above and their design features or their described combinations, but further encompasses modifications of the exemplary embodiments, in particular those encompassed by modifications of the features of the described examples or by combination or partial combination of individual or several of the features of the described examples within the scope of the independent claims. List of reference symbols

[0133] 10 Sequence of projected images

[0134] 10a Structured image / structured lighting

[0135] 10b Additional image / bright image / flat image / bright image

[0136] 100 Hand / Carrier of biometric features 110 biometric features

[0137] 400 recording volume

[0138] 410 translucent element / glass plate

[0139] 500 Lighting equipment / projector

[0140] 600 Image recording device / camera 700 Computing unit

[0141] 1000 detection devices

Claims

Patent claims 1. A method for contactless capture of biometric data of biometric features, in particular fingerprints, by means of a capture device, the method comprising: - Positioning the biometric features from which the biometric data is to be captured in a recording volume of the capture device, - illuminating the biometric features within the recording volume by means of an illumination device, wherein the illumination of the biometric features comprises at least one sequence of images projected onto the biometric features, - Recording the biometric features illuminated by the illumination device on the basis of the at least one sequence of projected images by means of an image recording device, - aligning at least one of the images of the biometric features recorded on the basis of the projected images of the at least one sequence of projected images with another image of the images of the biometric features recorded on the basis of the at least one sequence of projected images, and - Calculating the biometric data based on at least one aligned recording of the biometric features.

2. The method according to claim 1, wherein the at least one sequence of projected images comprises at least one additional projected image which is different from the remaining projected images of the at least one sequence of projected images, the method comprising: - aligning at least one of the images of the biometric features recorded on the basis of the projected images of the at least one sequence of projected images that are different from the projected additional image, with respect to at least one image of the biometric features recorded on the basis of the at least one projected additional image, and - Calculating the biometric data on the basis of the at least one image aligned with the image based on the at least one projected additional image the biometric characteristics based on the projected images different from the projected additional image.

3. The method according to claim 2, wherein at least two images of the images of the biometric features that were recorded on the basis of the projected images of the at least one sequence of projected images that are different from the projected additional image are aligned with respect to the at least one image of the biometric features that was recorded on the basis of the at least one projected additional image, and the biometric data are calculated on the basis of the images of the biometric features that are aligned with respect to the image based on the at least one projected additional image on the basis of the projected images that are different from the projected additional image. 4 Method according to claim 2 or 3, wherein the at least one projected additional image is illuminated to at least 90% of its projected image area, preferably is illuminated to at least 95% of its projected image area, particularly preferably is illuminated substantially over its entire area.

5. The method according to claim 4, wherein the unilluminated image areas of the at least one projected additional image are distributed over a substantial area of ​​the at least one projected additional image.

6. The method according to claim 2 or 3, wherein substantially at least the biometric features from which the biometric data are to be captured are completely illuminated by at least one illuminated image area of ​​the at least one projected additional image.

7. Method according to one of claims 4 to 6, wherein different brightness values ​​are present within the illuminated image area of ​​the at least one projected additional image, or the illuminated image area of ​​the at least one projected additional image is substantially uniformly illuminated.

8. Method according to one of claims 4 to 7, wherein the at least one projected additional image has brightness values ​​in the range 30 - 500 lux, preferably 75 - 350 lux, particularly preferably 150 - 260 lux for the illuminated image areas.

9. The method according to any one of claims 2 to 8, wherein the sequence of projected images comprises at least two structural images projected with structured light, preferably at least four structural images projected with structured light, particularly preferably at least ten structural images projected with structured light, which are different from the at least one additional image.

10. The method according to claim 9, wherein each of the projected structural images of the sequence of projected images has a line grating, in particular a line grating as a sinusoidal light-dark sequence, wherein the line width of the line gratings is different within the sequence of projected images.

11. The method according to claim 10, wherein within the sequence of projected images the line grids with wider line widths are arranged temporally before the line grids with narrower line widths, or within the sequence of projected images the line grids with narrower line widths are arranged temporally before the line grids with wider line widths.

12. The method according to any one of claims 2 to 11, wherein the at least one projected additional image is projected as the first image of the sequence of projected images, or the at least one projected additional image is projected as the last image of the sequence of projected images.

13. Method according to one of claims 2 to 11, wherein the at least one projected additional image is projected as a second image of the sequence of projected images, or at least one projected additional image is projected as the penultimate image in the sequence of projected images.

14. The method according to any one of claims 2 to 11, wherein the at least one projected additional image is projected as a third image of the sequence of projected images, or the at least one projected additional image is projected substantially in the middle of the sequence of projected images.

15. The method according to any one of claims 12 to 14 with claim 11, wherein the at least one projected additional image within the sequence of projected images is arranged substantially adjacent to the structural images of the line grids with the narrowest line widths within the sequence of projected images.

16. The method according to claim 11 or 15, wherein within the sequence of projected images the at least one projected additional image is arranged in time immediately before the structural images with the narrowest line widths of the line grids, or within the sequence of projected images the at least one projected additional image is arranged in time immediately after the structural images with the narrowest line widths of the line grids.

17. The method according to claim 11 or 15, wherein within the sequence of projected images, the at least one projected additional image is arranged substantially in the middle between the structural images with the narrowest line width of the line grids.

18. The method according to any one of claims 11 or 15 to 17, wherein the images of the biometric features recorded on the basis of the projected structural images with the narrowest line grid are aligned with respect to the image of the biometric features recorded on the basis of the at least one projected additional image, and the aligned images of the biometric features based on the structural images with the narrowest line grid are used to calculate the biometric data of the recorded biometric features.

19. Method according to one of the preceding claims, wherein the at least one sequence of projected images is carried out within a period of 100 milliseconds, preferably within 70 milliseconds, particularly preferably within 50 milliseconds, onto the area of ​​the biometric features.

20. The method according to any one of claims 9 to 19, wherein for the alignment, a pattern related to the biometric features is used within the images based on the projected structural images and within the image based on the at least one projected additional image.

21. The method according to claim 20, wherein the pattern comprises structures of the biometric features, in particular finger lines or skin pores.

22. The method according to claim 1, wherein the at least one sequence of projected images is at least a sequence of substantially identical images, in particular at least a sequence of substantially identical structural images projected with structured light.

23. Method according to one of the preceding claims, wherein calculating the biometric data comprises calculating the 3D information of the biometric data, in particular calculating the 3D information of the fingerprints.

24. Method according to one of the preceding claims, wherein the images of the at least one sequence of projected images comprise light having a wavelength of 420 - 490 nm, preferably 440 - 470 nm, particularly preferably 460 nm.

25. Device for contactless capture of biometric data of biometric features, in particular fingerprints, according to one of the preceding claims, wherein the device comprises: - a recording volume in which the biometric features from which the biometric data are to be recorded can be positioned, - an illumination device for illuminating the biometric features within the recording volume, wherein the illumination device is configured to project at least one sequence of images onto the biometric features for illuminating the biometric features, - an image recording device for recording the biometric features illuminated by the illumination device on the basis of the at least one sequence of projected images, and - a computing unit configured to align at least one of the images of the biometric features recorded on the basis of the projected images of the at least one sequence of projected images with respect to a further image of the images of the biometric features on the basis of the at least one sequence of projected images, and to calculate the biometric data on the basis of the at least one aligned image of the biometric features.

Images