Method for non-contact acquisition of biometric data from biometric features using an acquisition device, and device for non-contact acquisition of biometric data from biometric features.
The method improves non-contact 3D biometric data acquisition by using structured and unstructured illumination sequences to align and compensate for hand movements, ensuring high-quality 3D data capture.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- IDLOOP GMBH
- Filing Date
- 2024-03-14
- Publication Date
- 2026-05-13
Smart Images
Figure 2026515026000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for non-contact acquisition of biometric data from biometric features, particularly fingerprints, using an acquisition device, and a device for non-contact acquisition of biometric data from biometric features, particularly fingerprints.
Background Art
[0002] For the acquisition of biometric data from biometric features such as an individual's fingerprint, in addition to known methods of contact-based acquisition of biometric data, a non-contact method can also be used to acquire biometric data from biometric features.
[0003] However, for example, simply photographing biometric features using diffused light is often not sufficient to acquire high-quality biometric features such as fingerprints because the unevenness of the papillary lines cannot be clearly distinguished in the image information obtained by this method. Therefore, it is advantageous to perform 3D acquisition of biometric features.
[0004] However, non-contact 3D acquisition of very fine structures such as human fingerprints has a problem in that when people hold their hands or fingers above the corresponding acquisition device, it tends to cause small random movements of their hands or individual fingers, such as tremors or individual spasms, due to the tension or relaxation of the muscles of the hands or arms.
[0005] 3D data calculation based on the recording of biometric features using structured illumination is based on a dataset of raw images recorded sequentially, so when the hand is kept free in space, a method for correcting these movements must be performed. Movements change the orientation of the object with respect to the illuminating pattern / structure, which impairs the correlation of the recorded biometric features over individual recordings and thus leads to inaccurate 3D data, so this is necessary.
[0006] On the other hand, the structured lighting pattern / structure itself is dependent on the movement between the two records, and therefore has the greatest influence on the movement of the overall image information of the records; thus, relative alignment of the records is only possible to a limited extent.
[0007] Taking into account the shortcomings of known advanced technologies described above, the object of this patent application is to provide an improved method and corresponding device for contactless acquisition of biometric data from biocharacteristics, particularly fingerprints. [Overview of the Initiative]
[0008] This disclosure relates to a method for contactless acquisition of biometric data, particularly from fingerprints, using an acquisition device, and to a device for contactless acquisition of biometric data, particularly from fingerprints.
[0009] In particular, to solve the above-mentioned problems, a method for non-contact acquisition of biometric data, especially from fingerprints, using the acquisition device described in claim 1, and a device for non-contact acquisition of biometric data, especially from fingerprints, described in claim 25 are proposed. Dependent claims relate to some exemplary preferred embodiments.
[0010] According to a first aspect, several embodiments propose a method for non-contact acquisition of biometric data from biometric features, particularly fingerprints, using an acquisition device, the method comprising: positioning the biometric feature from which the biometric data is to be acquired within a recording volume of the acquisition device; illuminating the biometric feature within the recording volume using an illumination device, the illumination of the biometric feature comprising illuminating the biometric feature including at least one sequence of images projected onto the biometric feature; recording the biometric feature illuminated by the illumination device based on at least one sequence of projected images using an image recording device; aligning at least one record of the biometric feature records based on the projected images of at least one sequence of projected images with another record of the biometric feature records based on at least one sequence of projected images; and calculating biometric data based on at least one aligned record of the biometric feature.
[0011] In some preferred embodiments, the method may be further advantageous in that at least one sequence of projected images includes at least one additional projected image that is different from other projected images in the sequence of at least one projected image, and the method includes aligning at least one record of biofeedback recorded based on projected images of at least one sequence of projected images that is different from the additional projected image with at least one record of biofeedback recorded based on the additional projected image, and computing biodata based on the at least one record of biofeedback aligned with the record based on the additional projected image that is different from the additional projected image.
[0012] In some preferred embodiments, the method may be further advantageously developed in that at least two of the biofeature records recorded based on projected images of at least one sequence of projected images different from the additional projected image are aligned with at least one biofeature record recorded based on at least one additional projected image, and the biodata is computed based on the biofeature records aligned with the record based on at least one additional projected image different from the additional projected image.
[0013] In some preferred embodiments, the method can be further advantageously developed in such a way that at least one additional projected image is illuminated to at least 90% of its projected image area, preferably to at least 95% of its projected image area, and particularly preferably essentially over its entire area.
[0014] In some preferred embodiments, the method may be advantageously further developed such that the unilluminated image region of at least one additional projected image is distributed over a substantial area of at least one additional projected image.
[0015] In some preferred embodiments, the method may be further advantageously developed such that, essentially, the biological feature from which the biological data is acquired is fully illuminated by at least one illuminated image region of at least one additional projected image.
[0016] In some preferred embodiments, the method can be further advantageously developed in that different luminance values exist within the illuminated image area of at least one additional projected image, or the illuminated image area of at least one additional projected image is illuminated substantially uniformly.
[0017] In some preferred embodiments, the method can be further advantageously developed in which at least one additional projected image has a luminance value in the illuminated image area in the range of 30 to 500 lux, preferably 75 to 350 lux, and particularly preferably 150 to 260 lux.
[0018] In some preferred embodiments, the method can be advantageously further developed in that the sequence of projected images includes at least two structured light projected structural images, preferably at least four structured light projected structural images, and particularly preferably at least ten structured light projected structural images, which are distinct from at least one additional image.
[0019] In some preferred embodiments, the method can be further advantageously developed in which each of the projected structural images in the sequence of projected images comprises a line grid, particularly a line grid as a sinusoidal light-dark sequence, and the line widths of the line grid in the sequence of projected images are different.
[0020] In some preferred embodiments, the method can be further advantageously developed in such a way that, in the sequence of projected images, grids with wider line widths are positioned temporally earlier than grids with narrower line widths, or in such a way that, in the sequence of projected images, grids with narrower line widths are positioned temporally earlier than grids with wider line widths.
[0021] In some preferred embodiments, the method may be further advantageously developed in such a way that at least one additional projected image is projected as the first image in a sequence of projected images, or at least one additional projected image is projected as the last image in a sequence of projected images.
[0022] In some preferred embodiments, the method may be further advantageously developed in such a way that at least one additional projected image is projected as the second image in a sequence of projected images, or at least one additional projected image is projected as the second to last image in a sequence of projected images.
[0023] In some preferred embodiments, the method may be further advantageously developed in that at least one additional projected image is projected as a third image in the sequence of projected images, or at least one additional projected image is projected essentially in the middle of the sequence of projected images.
[0024] In some preferred embodiments, the method can be further advantageously developed in that at least one additional projected image is positioned within the sequence of projected images substantially adjacent to the line grid structure image having the narrowest line width in the sequence of projected images.
[0025] In some preferred embodiments, the method may be further advantageously developed in such a way that, within the sequence of projected images, at least one additional projected image is positioned immediately before the structural image having the narrowest line width of the grid, or within the sequence of projected images, at least one additional projected image is positioned immediately after the structural image having the narrowest line width of the grid.
[0026] In some preferred embodiments, the method may be further advantageously extended such that, within the sequence of projected images, at least one additional projected image is positioned essentially midway between the structural images having the narrowest line width of the grid.
[0027] In some preferred embodiments, the method can be further advantageously developed in that the recorded biometric based on the projected structural image having the narrowest line grating is matched with the recorded biometric based on at least one additional projected image, and the matched recorded biometric based on the structural image having the narrowest line grating is used to calculate the biometric data of the recorded biometric.
[0028] In some preferred embodiments, the method can be further advantageously developed in that at least one sequence of the projected images is projected onto the area of the biometric within 100 milliseconds, preferably within 70 milliseconds, particularly preferably within 50 milliseconds.
[0029] In some preferred embodiments, the method can be further advantageously developed in that, for matching, patterns within the recording based on the projected structural image and within the recording based on at least one additional projected image are used, and the patterns are related to the biometric.
[0030] In some preferred embodiments, the method can be further advantageously developed in that the patterns have the structure of the biometric, particularly the lines of the finger or the pores of the skin.
[0031] In some preferred embodiments, the method can be further advantageously developed in that at least one sequence of the projected images is at least one sequence of essentially identical images, particularly at least one sequence of structural images projected with essentially identical structured light.
[0032] In some preferred embodiments, the method can be further advantageously developed in that the calculation of the biometric data includes the calculation of the 3D information of the biometric data, particularly the calculation of the 3D information of the fingerprint.
[0033] In some preferred embodiments, the method may be advantageously further developed in such a way that at least one sequence of projected images includes light having wavelengths of 420–490 nm, preferably 440–470 nm, and particularly preferably 460 nm.
[0034] According to a second aspect, in some embodiments, a device is proposed for non-contact acquisition of biometric data from biometric features, particularly fingerprints, the device comprising: a recording volume in which biometric features from which biometric data can be located; an illumination device for illuminating biometric features in the recording volume, configured to project at least one sequence of images onto the biometric features for the purpose of illuminating the biometric features; an image recording device for recording the biometric features illuminated by the illumination device based on at least one sequence of projected images; and a computing unit configured to align at least one record of biometric feature records based on the projected images of at least one sequence of projected images with further records of biometric feature records based on at least one sequence of projected images, and to compute biometric data based on at least one aligned record of biometric features.
[0035] Further embodiments and their advantages, as well as the advantages and more specific embodiments of the embodiments and features described above, are described in the following descriptions and commentaries of the attached figures, and these should not be construed as limiting. [Brief explanation of the drawing]
[0036] [Figure 1] This diagram shows an illustrative flowchart of a method for non-contact acquisition of biometric data from biological characteristics. [Figure 2] This diagram illustrates an illustrative flowchart of further methods for non-contact acquisition of biometric data from biometric characteristics. [Figure 3]This figure illustrates an example of referencing multiple records of biological characteristics and reconciling them with another or additional record of those characteristics. [Figure 4] This figure shows examples of different series of exemplary structured illuminated recordings of biofeatures, along with exemplary unstructured illuminated recordings of biofeatures based on a sequence of projected images. [Figure 5] This figure shows examples of different unstructured illumination images for illuminating acquired biological features, or just very weakly structured illumination images for illuminating acquired biological features. [Figure 6] This figure shows an example of a device for non-contact acquisition of biometric data from biological characteristics. [Modes for carrying out the invention]
[0037] Examples and embodiments of this disclosure are described in detail below with reference to the accompanying drawings. Identical or similar elements in the drawings may be designated by the same reference numeral, but may occasionally be designated by different reference numerals.
[0038] It should be emphasized that the subject matter of this disclosure is by no means limited to or restricted to the embodiments and features described below, and also includes modifications of the embodiments, in particular modifications that are included, within the scope of protection of the independent claims, by modifications of the features of the described examples, or by individual features or combinations of some features of the described examples.
[0039] Figure 1 shows an illustrative flowchart of a method for contactless acquisition of biometric data from biometric features 110, particularly fingerprints 110, using an acquisition device 1000, with reference to Figure 6 for all features relating to the acquisition device 1000 and the biometric features 110 or fingerprints 110.
[0040] In the first step S101, the biometric features to be recorded, such as the fingerprints 110 of the hand 100, are non-contactually positioned within the recording volume 400 of the acquisition device 1000.
[0041] The recording volume 400 of the acquisition device 1000 may be, for example, an area above the opening of the acquisition device 1000, which is covered by, for example, a light-transmitting element 410 (e.g., a glass plate that protects from dust and dirt), and within it, for example, the hand 100 as a carrier of the biometric features 110 to be acquired is kept without contact (without physical contact with the acquisition device 1000).
[0042] Furthermore, the acquisition device 1000 is configured to provide corresponding feedback on the current position of the hand 100 and / or the target position, for example, so that the hand 100 or the biometric features 110 can be positioned within a certain tolerance range in a recording volume 400 for recording the biometric features 110.
[0043] In a further step S102, the acquired biofeedback 110 can be illuminated by the illumination device 500 within the capture volume 400 of the acquisition device 1000. In this process, images 10a and 10b are projected onto the area of the acquired biofeedback 110 by the illumination device 500 (for example, formed as a projector 500).
[0044] In particular, the illumination device 500 projects at least one sequence 10 of images 10a, 10b onto the region of the acquired biofeedback 110, and the projected sequence 10 of images 10a, 10b can be designed to be very different, for example, with respect to the number of images 10a, 10b. For example, the sequence 10 may include 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). In this regard, it should be noted that some of the images within the sequence 10 of images 10a, 10b may also include additional images.
[0045] Furthermore, it may be advantageous if at least one sequence 10 of images 10a, 10b projected onto the acquired biofeedback 110 includes at least one structured image 10a (structured illumination), preferably several structured images 10a. These can be advantageously used, for example, to acquire the topology of the structure of the biofeedback 110, particularly its height and depth. A more accurate topology of the biofeedback 110 can lead to better acquisition of the quality of the biodata calculated thereafter, particularly the 3D biodata of the biofeedback 110.
[0046] Suitable structures for the projected structural image 10a include, for example, a line grid, particularly a sinusoidal light-dark sequence, in which the lines (dark areas) and / or intermediate areas (bright or illuminated areas) have essentially the same width. Furthermore, while the line width, and therefore area, of the projected image 10a remains constant, the number of lines within each structural image 10a may vary between individual projected images 10a within the sequence 10 of projected images 10a, 10b.
[0047] An example of at least one sequence 10 of projected images 10a, 10b may be such that the structural image 10a having a wider line width grid is placed temporally earlier in the sequence 10 of images 10a, 10b than the structural image 10a having a narrower line width grid, or the structural image 10a having a larger (maximum) / wider (broadest) line width is placed first in the sequence 10, and the line width decreases as the sequence 10 of projected images 10a, 10b progresses, so that the structural image 10a having a wider line width grid is placed temporally earlier in the sequence 10 of images 10a, 10b, or projected onto the biological features 110 respectively.
[0048] In this context, however, it may also be advantageous for a structural image 10a with a smaller (minimum) / narrower (most narrow) line width to be placed first in sequence 10, and for the line width to increase as sequence 10 of projected images 10a and 10b progresses, so that a structural image 10a with a narrower line width grid is placed or projected onto the biological feature 110 before a structural image 10a with a wider line width grid in sequence 10 of images 10a and 10b.
[0049] Furthermore, structural images 10a within at least one sequence 10 of projected images 10a, 10b that essentially have the same line width or the same grid will exhibit a slight shift in the position of the lines or grid, particularly orthogonal to the line direction (e.g., a phase shift in a sinusoidal light-dark sequence). This shift may be continuous, for example, from each structural image 10a with a certain line width of the grid to the next structural image 10a with the same line width of the grid, such that within at least one sequence 10 of projected images 10a, 10b, there are at least four structural images 10a with the same line width of the grid, but each of these four structural images 10a with the same line width has a grid offset / shift or phase shift relative to the other three structural images 10a. It should be noted that the number of structural images 10a with the same line width of the grid may be fewer (e.g., two or three) or more (e.g., six, eight, etc.).
[0050] The phase shift or displacement of the line grid within each structural image 10a can increase the accuracy of the acquired biofeatures 110, or conversely, enable the complete acquisition of the biofeatures 110.
[0051] In this regard, it should be noted that illumination of the acquired biofeatures 110 can be achieved by multiple sequences 10 of projected images 10a, 10b, for example, sequences 10 to 100 of projected images 10a, 10b, or as long as the sequences 10 of projected images 10a, 10b are repeated until biofeatures 110 of one hand 100 or both hands are acquired.
[0052] In a further step S103, the area of the biofeed 110 illuminated by the illumination device 500 may be recorded by the image recording device 600. For this purpose, the illuminated biofeed 110 can be recorded in image or photographic form using a multi-line or two-dimensional optical sensor / photodetector (such as a high-resolution camera having a CMOS sensor / active pixel sensor (APS) or CCD sensor, for example, 0.3 megapixels or up to 50 megapixels).
[0053] A further step S104 may be performed, in which a biometric feature 110, or at least one recording of a biometric feature 110, recorded by the image recording device 600 is aligned with a further recording of the biometric feature 110 based on at least one sequence 10 of projected images 10a, 10b. For example, the recorded biometric feature 110 can be aligned using a pattern associated with the biometric feature 110, in which case the pattern may have, for example, finger lines and / or skin pores (and / or scars and / or wrinkles) as reference points or reference structures in the recording of the biometric feature 110 based on at least one sequence 10 of images 10a, 10b.
[0054] In this regard, it should be noted that, for example, at least two records of the biometric feature 110, in particular at least four (or six or eight, etc.) records of the biometric feature 110, or all of the records of the biometric feature 110, may preferably be harmonized, and in particular may be harmonized with one another.
[0055] Furthermore, in the case of several sequences 10 of projected images 10a and 10b, it is advantageous to align the recordings of biofeatures 110 such that only those recordings of biofeatures 110 recorded within one of the sequences 10 are aligned. This has the advantage of avoiding excessively long time intervals between individual recordings from which biodata, particularly 3D biodata, is calculated, and also avoids subsequent "stitching" of biofeatures recorded at relatively different times.
[0056] Furthermore, the biometric features 110 (e.g., the structure or substructure of a fingerprint) themselves can be used as patterns to match the recorded biometric features 110 (see, for example, Figure 3).
[0057] This is particularly advantageous because keeping the exemplary hand 100, as a carrier of the biometric features 110 to be recorded, in a non-contact manner within the recording volume 400 of the acquisition device 1000 means that the movement of the hand 100 cannot be obstructed. In particular, small movements that are not controllable by the human (e.g., tremors or spasms of the hand or individual fingers due to tension and / or relaxation of the muscles of the hand or arm) can have a significant impact on the quality of the biometric data, especially the 3D data or 3D biometric data that can be obtained from the recording of the biometric data 110.
[0058] Furthermore, when using structured lighting, a problem may arise in which the displacement of the grid from one structured image 10a to the next structured image 10a in at least one sequence 10 of projected images 10a, 10b must be corrected / calculated in addition to the movement of the hand 100 relative to the acquisition device 1000 or the lighting and image recording devices 500, 600, but this can be done by aligning the recording of biofeatures 110.
[0059] In a further step S105, biometric data, in particular 3D biometric data, may be computed here based on at least one consistent record of the biometric features 110 (in particular, based on records of biometric features 110 that are consistent with each other) and provided for further processing, such as storage, comparison with known or existing records and / or biometric data.
[0060] In this regard, it should be noted that, for example, the structural image 10a may have light having a wavelength of 420-490 nm, preferably 440-470 nm, and particularly preferably 460 nm. This wavelength of projected light may be advantageous for recording biofeatures 110 (particularly advantageous for higher resolution of the recorded biofeatures 110) and may be advantageous for subsequent matching of the recording of biofeatures 110 due to the scattering properties of the skin.
[0061] The described method can favorably compensate for (uncontrolled) hand movements and structured lighting movements (shift / phase shift) between individual recordings of biofeatures 110, thereby significantly reducing the impact of these movements of biofeatures 110 on the quality of biodata, particularly 3D biodata.
[0062] Figure 2 shows an illustrative flowchart of a further method for contactless acquisition of biometric data from biometric features 110, particularly fingerprints 110, using an acquisition device 1000. In this regard, Figure 6 is also referenced for all features related to the acquisition device 1000 and the biometric features 110 or fingerprints 110.
[0063] Steps S201 and S202 can essentially be carried out as described in steps S101 and S102 of Figure 1. It should also be noted that the exemplary method shown in Figure 2 may represent a further development of the exemplary method shown in Figure 1.
[0064] However, in step S202, in contrast to step S102 according to Figure 1, at least one sequence 10 of images 10a, 10b is modified in that at least one sequence 10 of images 10a, 10b also includes at least one additional image 10b which is different from other images 10a (such as structural image 10a) projected by the illumination device 500 onto the acquired biofeed 110.
[0065] At least one additional image region of image 10b may essentially consist only of bright regions (also referred to as "flat images" or "bright images"), or, in contrast to the structured image 10a, at least one additional image region of image 10b may essentially have no dark regions (unlit regions).
[0066] Furthermore, at least one projected additional image 10b may be illuminated over at least 90% of its projected image area, preferably at least 95% of its projected image area, and particularly preferably substantially over its entire area (see, e.g., Figures 5(a) and (b)). The unilluminated area / unilluminated image area of the additional image 10b may constitute a very small proportion of the additional image 10b projected onto the biological features, and in this regard, the unilluminated image area of at least one projected additional image 10b may be distributed over a substantial area of at least one projected additional image 10b (e.g., at least 50%, particularly at least 75%, of the image area of at least one projected additional image 10b) (see, e.g., Figures 5(c) and (d)).
[0067] Furthermore, in this context, the additional image 10b has very fine dark areas that are essentially distributed throughout the entire image area of the additional image 10b (see, for example, Figures 5(c) and (d)). These fine dark areas may be formed as fine lines, for example, so that they essentially disappear in the recording of the biofeedback 110 and are detected as illuminated areas, possibly just dimly illuminated areas, by the image recording device 600 of the acquisition device 1000, or they may be reflected from the surface of the biofeedback 110 (e.g., the skin of the hand 100).
[0068] Furthermore, at least one additional image 10b may substantially illuminate at least one biological feature 110 on which biological data is recorded, entirely through the illuminated image region of at least one projected additional image 10b.
[0069] Furthermore, the illuminated image regions of at least one additional image 10b may have different luminance values. In particular, the luminance values may be in the range of 30 to 500 lux, preferably 75 to 350 lux, and especially preferably 150 to 260 lux. A single illuminated image region of at least one additional image 10b may also simultaneously have different luminance values. In addition, the illuminated regions of the structural image 10a may have the aforementioned luminance values.
[0070] Here, in step S202, the biometric features to be recorded 110 may be recorded in the recording volume 400 of the acquisition device 1000 by the illumination device 500 by at least one sequence 10 of images 10a, 10b, which includes, for example, at least two structural images 10a, preferably at least four structural images 10a, particularly preferably at least ten structural images 10a, and at least one additional image 10b.
[0071] For example, at least one additional projected image 10b may be projected onto the biofeature 110 as the first image in the sequence 10 of projected images 10a, 10b, or at least one additional projected image 10b may be projected onto the biofeature 110 as the last image in the sequence 10 of projected images 10a, 10b.
[0072] For example, at least one additional projected image 10b may be projected onto the biological feature 110 as the second image in the sequence 10 of projected images 10a, 10b, or at least one additional projected image 10b may be projected onto the biological feature 110 as the second to last image in the sequence 10 of projected images 10a, 10b.
[0073] Furthermore, at least one sequence 10 of projected images 10a, 10b may also be designed such that at least one additional projected image 10b is projected onto the biofeature 110 as the third image in the sequence 10 of projected images 10a, 10b, or at least one additional projected image 10b is projected onto the biofeature 110 essentially in the middle of the sequence 10 of projected images 10a, 10b.
[0074] However, it may also be advantageous if at least one additional projected image 10b is positioned substantially adjacent to the line grid structure image 10a having the narrowest line width within the sequence of projected images 10a, 10b.
[0075] This may be advantageous because the image of the biofeatures 110 recorded based on the projected structural image 10a having the narrowest grid can be matched with the recording of the biofeatures 110 based on at least one additional projected image 10b, and the matched recording of the biofeatures 110 based on the structural image 10a having the narrowest grid can be advantageously used to compute the biodata of the recorded biofeatures 110.
[0076] This ensures, for example, that individual recordings of biofeatures 110 based on structural image 10a and recordings of biofeatures 110 based on additional image 10b are temporally related to each other, particularly that the time interval between individual images is very short, and as a result, the movement of the hand 100 or biofeatures 110 within the thus maintained very short period can also be very slight.
[0077] Furthermore, the additional image 10b may be placed at the beginning of at least one sequence 10 of the projected images 10a, 10b, or immediately before the structural image 10a having the narrowest line width; or the additional image 10b may be placed at the end of at least one sequence 10 of the projected images 10a, 10b, or immediately after the structural image 10a having the narrowest line width; or the additional image 10b may be placed essentially in the middle between the structural images 10a having the narrowest line widths in at least one sequence 10 of the projected images 10a, 10b (see, for example, Figure 4).
[0078] Furthermore, at least one additional image 10b may also have light having a wavelength of 420-490 nm, preferably 440-470 nm, and particularly preferably 460 nm, which, like the structural image 10a, has the advantages already described.
[0079] In this regard, it should be noted that illumination of the biofeatures 110 to be recorded can be achieved by multiple sequences 10 of projected images 10a, 10b, for example, sequences 10 to 100 of projected images 10a, 10b, or as long as the sequences 10 of projected images 10a, 10b are repeated until the biofeatures 110 (for example, of one hand 100 or both hands) are recorded.
[0080] Which of the recordings of biofeatures 110 recorded by the image recording unit 600 is ultimately used to compute biodata, particularly 3D biodata, may depend, for example, on the movement of the hand or biofeatures 110 being acquired (e.g., tremor). For example, it may be advantageous if the movement of the hand or biofeatures 110 being acquired is detected during the recording of the biofeatures 110 and evaluated to determine which sequence 10 of the projected images 10a, 10b had the least movement, and then the corresponding recording of the biofeatures 110 in this sequence 10 of the projected images 10a, 10b is used for subsequent computation of biodata (particularly 3D biodata). This allows for further optimization of the quality of image information for 3D data computation, for example.
[0081] Here, in step S203, as in step S103 of Figure 1, the area of the biofeed 110 illuminated by the illumination device 500 may be recorded visually or photographically by the image recording device 600, and in this regard, for this purpose a multi-line or two-dimensional optical sensor / photodetector (such as a high-resolution camera having a CMOS sensor / APS or CCD sensor, for example, 0.3 megapixels or up to 50 megapixels) may be used again for this purpose.
[0082] In a further step S204, similar to step S104 in Figure 1, at least one of the recordings of biofeatures 110 recorded based on the projected images (e.g., structural image 10a) of at least one sequence 10 of projected images 10a, 10b, which is different from the additional projected image 10b, is matched with at least one recording of biofeatures 110 recorded based on at least one additional projected image 10b.
[0083] For this purpose, as already described, for example, recording or at least one of the biofeatures 110 based on the structural image 10a having the narrowest line width can be coordinated with recording the biofeatures 110 based on at least one additional image 10b, since the recording of biofeatures 110 based on these structural images 10a may have the highest information content for subsequent calculations of biodata, particularly 3D biodata.
[0084] In this regard, it should be noted that, for example, at least two records of biological features 110 based on structural image 10a may be consistent with a record of biological features 110 based on at least one additional image 10b, or, for example, at least four (or six or eight, etc.) records of biological features 110 based on structural image 10a may be consistent with a record of biological features 110 based on at least one additional image 10b.
[0085] In this case, patterns associated with the biofeatures 110 may also be used to match the recorded biofeatures 110, in which case the patterns may include, for example, finger lines and / or skin pores (and / or scars and / or wrinkles) as reference points or reference structures in the recording of the biofeatures 110 based on at least one sequence 10 of projected images 10a, 10b.
[0086] Furthermore, the biometric features 110 (e.g., the structure or substructure of a fingerprint) themselves can be reused as patterns to match the recorded biometric features 110 (see, for example, Figure 3).
[0087] Here, in step S205, the biodata is recalculated based on a recording of at least one biofeature 110 that is consistent with the recording based on at least one additional projected image 10b, which is based on a projected image (e.g., a structural image 10a) different from the additional projected image 10b. In this regard, as already described, the recording of biofeature 110 based on the structural image 10a having the narrowest line width of the grid may be used in the calculation of the biodata.
[0088] In addition to the known advantages of compensating for (uncontrolled) hand movements and structured lighting movements (shift / phase shift) between individual recordings of biofeeds 110, the described method using at least one additional image 10b can also be used to very reliably match the recorded biofeeds 110, thereby significantly increasing the quality of the image data required to compute biodata (particularly 3D biodata).
[0089] Furthermore, if individual images exhibit, for example, a phase shift of the line grid of their projected structural images 10a, they have significantly higher image information content than a single record of the biofeatures 110, and this higher image information content can be advantageous, especially for computation of biodata, particularly 3D biodata, so at least two (or more) records of the biofeatures 110 can be combined and used for subsequent computation of biodata, particularly 3D biodata.
[0090] Figure 3 shows an example of referencing several records of biometric features 110 and aligning them with further or additional records of biometric features 110.
[0091] At the top of Figure 3, an exemplary sequence 10 of projected images 10a and 10b can be seen, in which case only the representation of the structural image 10a in sequence 10 is shown here, and at least one additional image 10b is shown at the bottom of Figure 3.
[0092] The exemplary sequence 10 of projected images 10a and 10b demonstrates how the line grid of the structural image 10a changes within sequence 10, showing that the line width of the line grid of the initial structural image 10a (see representation (a) in Figure 3) has the widest line width within sequence 10. This line width or line grid can be changed here as sequence 10 of projected images 10a and 10b progresses, in this example, by decreasing the line width (see representation (e) in Figure 3) or by increasing the number of lines while maintaining the same image area of the projected structural image 10a.
[0093] At the end of the exemplary sequence 10 of projected images 10a, 10b, a structural image 10a having the narrowest or narrowest line width of the grid is placed here (see example figures (v) to (y) in Figure 3), in which case the additional image 10b may be advantageously placed adjacent to these structural images 10a. In this example, the additional image 10b is placed chronologically after the four exemplary structural images 10a having the narrowest line width (this may be seen in figure 3 (z), where representation (z) in Figure 3 shows a recording of biofeatures 110 based on the additional image 10b, where the additional image 10b is illuminated across its entire surface in this example and therefore has no grid as in the case of representations (v) to (y) in Figure 3). However, at least one additional image 10b can of course be placed at any other position in the sequence 10 of projected images 10a, 10b, and in this regard, it is advantageous if at least one additional image 10b is placed at least substantially adjacent to the structural image 10a, and the recording of the biological features 110 of the structural image 10a is later reconciled with the recording of the biological features 110 based on at least one additional image 10b (see also, e.g., Figure 4).
[0094] The middle section of Figure 3 also shows, as an example, how the recorded biofeedback, symbolically represented here as a fingerprint 110, moves within the recording area (for example, due to hand movements that may be explained when the hand 100 is held within the recording area 400 of the acquisition device 1000), as initially shown in the upper section of Figures (v) to (y) without the grid of the projected structural image 10a. Furthermore, as shown in the lower section of Figures (v) to (y), it is shown how the projected structural image 10a with the narrowest line width shifts between images (for example, from image (v) to image (y) in Figure 3) and how it shifts additionally with respect to the acquired biofeedback 110 (a shift / phase shift of the grid within the projected structural image 10a).
[0095] On the one hand, due to the movement of the hand 100 or biofeedback 110 being recorded, and on the other hand, due to additional movement of the grid within the projected structural image 10a, it may be very advantageous to provide at least one additional image 10b (see representation (z) in Figure 3) within the sequence 10 of projected images 10a, 10b in order to correct or compensate for these movements for the acquisition of the biofeedback 110.
[0096] Based on the recording of the biofeatures 110 based on at least one additional image 10b (here, representation (z) in Figure 3), the remaining recordings of the biofeatures 110, in particular, the recordings based on the line grid with the narrowest line widths, can here be harmonized with the recordings based on at least one additional image 10b (see, for example, representation (v)+(w)+(x)+(y)+(z) in Figure 3; in this regard, the line grids in representations (v)~(y) in Figure 3 are omitted for better visual clarity).
[0097] As already explained, patterns in the recording may be used for matching purposes, and in some cases, parts of the structure of the recorded biofeatures 110, or other patterns / structures such as finger lines or skin pores or scars or wrinkles may also be used.
[0098] Figure 4 shows exemplary representations of different series of exemplary structured illuminated recordings of biofeatures 110, along with exemplary unstructured illuminated recordings of biofeatures 110 based on sequence 10 of projected images 10a, 10b.
[0099] For this purpose, not only are four records of the biofeature 110 having the narrowest line width of the grid always shown as examples, but one record of the biofeature 110 having a very coarse grid or very wide lines is also always shown as an example, in which case this record is always placed at the beginning of the series of records as an example, and one record of the biofeature 110 based on at least one additional image 10b is also always shown as an example, their possible positions are described below as examples.
[0100] For example, as shown in the series representation (A) of Figure 4, at least one additional image 10b for recording biological features 110 may be placed at the beginning or immediately before the structural image 10a having the narrowest line width of the grid for recording biological features 110, such that the recording (w) based on the structural image 10a is immediately adjacent to the recording (v) based on at least one additional image 10b, and the recording (z) based on the structural image 10a is somewhat separated from the recording (v) based on at least one additional image 10b, but essentially adjacent to the recording (v) based on at least one additional image 10b.
[0101] In a further exemplary series represented by (B) in Figure 4, however, the recording (y) based on structural image 10a is immediately adjacent to the recording (z) based on at least one additional image 10b, and the recording (v) based on structural image 10a is somewhat distant from the recording (z) based on at least one additional image 10b, but essentially adjacent to the recording (z) based on at least one additional image 10b, so that at least one additional image 10b may also be placed at the end or immediately after structural image 10a having the narrowest line width of the grid for recording biological features 110.
[0102] In a further exemplary series of representations (C) in Figure 4, the records (w) and (y) based on structural image 10a are immediately adjacent to the record (x) based on at least one additional image 10b, and the records (v) and (z) based on structural image 10a are somewhat separated from the record (z) based on at least one additional image 10b, but these records are also essentially adjacent to the record (x) based on at least one additional image 10b, such that at least one additional image 10b can be essentially positioned between or between structural images 10a having the narrowest line width of the grid for recording the biological features 110.
[0103] Advantageously, when the records are arranged by representation (C), it can be ensured that none of the records based on structural image 10a are further than two records from at least one additional record based on image 10b, and in addition, two of the records based on structural image 10a are immediately adjacent to at least one additional record based on image 10b. This has the advantage of further reducing the impact of hand movements or acquired biofeatures on the quality of image information for subsequent computation of biodata, particularly 3D biodata.
[0104] However, all three exemplary series of recordings of biofeeds 110 have the advantage that the recording based on the structural image 10a having the narrowest line width of the grid is essentially adjacent to the recording of biofeeds 110 based on at least one additional image 10b, and conversely, the structural image 10a having the narrowest line width of the grid is essentially adjacent to at least one additional image 10b in sequence 10.
[0105] To minimize the impact of hand 100 or the biofeedback 110 being recorded, it may be advantageous to keep the time width of the sequence 10 of projected images 10a, 10b (shown in Figure 4 as the time width t from the first recording (a) to the last recording (z)) as short as possible. For example, at least one sequence 10 of projected images 10a, 10b may be projected onto an area of the biofeedback 110 within a time width of 100 milliseconds, preferably within 70 milliseconds, and particularly preferably within 50 milliseconds, and the biofeedback 110 may be recorded accordingly.
[0106] In this regard, even though these possibilities are not shown in Figure 4, it should be noted that the arrangement of the structural image 10a with the narrowest line width of the grid can also be placed in the middle or at the beginning of the sequence 10 of projected images 10a, 10b.
[0107] Figure 5 shows exemplary representations of various unstructured illumination images 10b for illuminating the recorded biological features 110, or just very weakly structured illumination images 10b for illuminating the recorded biological features 110.
[0108] In representation (a) of Figure 5, an example of an image 10b (e.g., an additional image 10b) illuminated essentially across its entire surface for projection onto the biofeedback 110 to be recorded (e.g., by an illumination device 500), where different luminance values may exist within this fully illuminated image 10b (e.g., luminance values in the range of 30 to 500 lux, preferably 75 to 350 lux, and particularly preferably 150 to 260 lux; different luminance values are shown here as an example by diagonal hatching, in which hatching with a small distance between lines is intended to represent lower luminance values than hatching with a large distance between lines).
[0109] In contrast, Figure 5(b) shows an example of an additional image 10b for projection onto a bio-feature 110 by an illumination device 500 (formed, for example, as a projector 500), where the image 10b is essentially uniformly illuminated across its entire surface (shown as uniform diagonal hatching).
[0110] Example figures (c) and (d) of Figure 5 essentially show image 10b relative to at least one additional projected image 10b, in which at least 90%, preferably at least 95%, of the projected image area is illuminated. Unilluminated image areas are indicated by vertical lines, and these vertical lines have illuminated image areas between them.
[0111] In particular, the unilluminated image region of at least one projected additional image 10b shown in representation (d) of Figure 5 is distributed over a substantial area of at least one projected additional image 10b (e.g., at least 50%, and especially at least 75%, of the image region of at least one projected additional image 10b). In contrast, in representation (c), the unilluminated image region of the additional image 10b is distributed essentially at the edges of the additional image 10b.
[0112] Figure 6 shows an exemplary representation of a device 1000 for contactless acquisition of biometric data from biometric features 110.
[0113] The device 1000 / acquisition device 1000 may have a recording volume 400 in which a biometric feature 110 (e.g., a fingerprint 110 of a hand 100) on which biometric data is recorded can be positioned without any particular contact.
[0114] The recording volume 400 of the acquisition device 1000 may be, for example, an area above a simple opening of the acquisition device 1000, which is covered by, for example, a light-transmitting element 410 (e.g., a glass plate that protects from dust and dirt), and within it, for example, a hand 100 as a carrier of the biometric features 110 to be recorded is held without contact.
[0115] The acquisition device 1000 may also have an illumination device 500 for illuminating the biological features 110 in the recording volume 400, and the illumination device 500 is configured to project at least one sequence 10 of images 10a, 10b onto the biological features 110.
[0116] The lighting device 500 may be configured as a projector 500 that projects various images of at least one sequence 10 of projected images 10a, 10b (e.g., structural images 10a of different line grids or line grids with different line widths, and at least one additional image 10b, etc.) onto the biofeedback 110 to be recorded, for example, within 100 milliseconds, 70 milliseconds, or 50 milliseconds.
[0117] Furthermore, the acquisition device 1000 may include an image recording device 600 for recording biological features 110 illuminated by the illumination device 500 based on at least one sequence 10 of projected images 10a, 10b.
[0118] The image recording device 600 may be formed, for example, as a camera 600 having a resolution of 0.3 megapixels to 50 megapixels, and in this regard, the image recording device 600 / camera 600 may also include at least one multi-line or two-dimensional CMOS sensor (or APS) or CCD sensor.
[0119] Furthermore, the acquisition device 1000 may include a computing unit 700 configured to reconcile at least one record of biometric feature 110 taken based on at least one sequence 10 of projected images 10a, 10b with further records of biometric feature 110 based on at least one sequence 10 of projected images 10a, 10b.
[0120] Furthermore, the computing unit 700 may be configured to compute biometric data, particularly 3D biometric data, based on at least one aligned record of the biometric features 110 (aligned to another record of the biometric features 110 (as shown in Figure 1) or to a record based on an additional image 10b (as shown in Figure 2)), thereby enabling the acquired or computed biometric data to be stored for further use or compared with known biometric data.
[0121] Furthermore, the computing unit 700 may be configured to control all devices such as the illumination device 500 (and thus the sequence 10 of projected images 10a, 10b) and / or the image recording device 600 of the acquisition device 1000 (and thus the recording of biometric features 110).
[0122] Furthermore, the acquisition device 1000 may be configured to provide feedback on the current position of the hand 100 and / or the target position of the hand 100 within the recording volume 400, for example, so that the hand 100 or biometric feature 110 is positioned within a certain tolerance range within the recording volume 400 for recording the biometric feature 110.
[0123] It should be noted that only examples or embodiments and technical advantages of this disclosure have been described in detail with reference to the accompanying drawings. However, this disclosure is by no means limited to the embodiments and features or combinations thereof described above, and also includes, within the scope of protection of the independent claims, modifications of embodiments, in particular modifications of features of the described examples, or combinations or partial combinations of individual or some features of the described examples. [Explanation of Symbols]
[0124] 10. Sequence of projected images 10a Structured images / structured lighting 10b Additional images / Shiny images / Flat images 100 hands / carriers of bio-characteristics 110 Biological characteristics 400 recording volume 410 Light-transmitting element / glass plate 500 Lighting Devices / Projectors 600 Image Recording Devices / Cameras 700 computing units 1000 Acquisition Devices
Claims
1. A method for non-contact acquisition of biometric data, particularly from fingerprints, using an acquisition device, The biological characteristics from which the biological data is captured are positioned within the recording volume of the acquisition device, Illuminating the biological features in the recording volume using an illumination device, The illumination of the biological feature includes a sequence of at least one image projected onto the biological feature. To illuminate, Using an image recording device, the biological features illuminated by the illumination device are recorded based on at least one sequence of projected images. To reconcile at least one record of the biological features recorded based on the projected images of at least one sequence of projected images with another record of the biological features based on the at least one sequence of projected images, Calculating the biological data based on the at least one consistent record of the biological characteristics. Methods that include...
2. The at least one sequence of projected images includes at least one additional projected image that is different from the other projected images in the at least one sequence of projected images, The aforementioned method includes the following: To align at least one of the records of the biometric features recorded based on the projected images of at least one sequence of projected images different from the additional projected images with at least one record of the biometric features recorded based on the at least one additional projected image, Calculating biometric data based on at least one record of the biometric features consistent with the record based on the at least one projected additional image which is different from the projected additional image, The method according to claim 1.
3. At least two of the records of the bio-characteristics recorded based on the projected images of the at least one sequence of projected images different from the additional projected images are aligned with the at least one record of the bio-characteristics recorded based on the at least one additional projected image. The method of claim 2, wherein the biological data is calculated based on a record of the biological features, which is consistent with the record based on the at least one projected additional image that is different from the projected additional image.
4. The method according to claim 2 or 3, wherein the at least one additional projected image is illuminated to at least 90% of its projected image area, preferably to at least 95% of its projected image area, and particularly preferably substantially over its entire area.
5. The method according to claim 4, wherein the unilluminated image region of the at least one additional projected image is distributed over a substantial area of the at least one additional projected image.
6. The method according to claim 2 or 3, wherein at least the biological feature from which the biological data is acquired is substantially fully illuminated by at least one illuminated image region of the at least one additional projected image.
7. If different luminance values exist within the illuminated image region of the at least one additional projected image, or The method according to any one of claims 4 to 6, wherein the illuminated image region of the at least one additional projected image is illuminated in an essentially uniform manner.
8. The method according to any one of claims 4 to 7, wherein the at least one additional projected image has a luminance value in the illuminated image area in the range of 30 to 500 lux, preferably 75 to 350 lux, and particularly preferably 150 to 260 lux.
9. The method according to any one of claims 2 to 8, wherein the sequence of projected images includes at least two structured images projected with structured light, preferably at least four structured images projected with structured light, and particularly preferably at least ten structured 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 in the sequence of projected images has a line grid, particularly as a sinusoidal light-dark sequence, and the line widths of the line grid in the sequence of projected images are different.
11. In the sequence of projected images, the grid lines having wider line widths are positioned temporally earlier than the grid lines having narrower line widths, or The method according to claim 10, wherein in the sequence of projected images, the grids having narrower line widths are positioned temporally earlier than the grids having wider line widths.
12. The at least one additional projected image is projected as the first image in the sequence of projected images, or The method according to any one of claims 2 to 11, wherein the at least one additional projected image is projected as the last image in the sequence of projected images.
13. The at least one additional projected image is projected as the second image in the sequence of projected images, or The method according to any one of claims 2 to 11, wherein the at least one additional projected image is projected as the second to last image in the sequence of projected images.
14. The at least one additional projected image is projected as the third image in the sequence of projected images, or The method according to any one of claims 2 to 11, wherein the at least one additional projected image is projected essentially in the middle of the sequence of projected images.
15. The method according to any one of claims 12 to 14, in addition to claim 11, wherein the at least one additional projected image is positioned in the sequence of projected images substantially adjacent to the structural image of the line grid having the narrowest line width in the sequence of projected images.
16. Within the sequence of projected images, the at least one additional projected image is positioned immediately before the structural image having the narrowest line width of the grid, or The method according to claim 11 or 15, wherein in the sequence of projected images, the at least one additional projected image is positioned immediately after the structural image having the narrowest line width of the grid.
17. The method according to claim 11 or 15, wherein in the sequence of projected images, the at least one additional projected image is positioned substantially midway between the structural images having the narrowest line width of the grid.
18. The method according to any one of claims 11 or 15 to 17, wherein the record of the biofeatures recorded based on the projected structural image having the narrowest grid is matched with the record of the biofeatures based on the at least one additional projected image, and the matched record of the biofeatures based on the structural image having the narrowest grid is used to calculate the biodata of the recorded biofeatures.
19. The method according to any one of claims 1 to 18, wherein the at least one sequence of projected images is projected onto the region of the biological feature within a time width of 100 milliseconds, preferably within 70 milliseconds, and particularly preferably within 50 milliseconds.
20. The method according to any one of claims 9 to 19, wherein for matching purposes, patterns in the recording based on the projected structural image and patterns in the recording based on the at least one additional projected image are used, and the patterns are related to the biological features.
21. The method according to claim 20, wherein the pattern includes the biological features, particularly the lines on the fingers or the structure of pores in the skin.
22. The method according to claim 1, wherein the at least one sequence of projected images is at least one sequence of essentially identical images, in particular at least one sequence of at least one essentially identical structural images projected with structured light.
23. The method according to any one of claims 1 to 22, wherein the calculation of the biometric data includes the calculation of 3D information of the biometric data, in particular the calculation of 3D information of the fingerprint.
24. The method according to any one of claims 1 to 23, wherein the image of at least one sequence of projected images includes light having a wavelength of 420 to 490 nm, preferably 440 to 470 nm, and particularly preferably 460 nm.
25. A device for non-contact acquisition of biometric data from biometric characteristics, particularly fingerprints, according to any one of claims 1 to 24, A recording volume in which the biological data is recorded and in which the biological characteristics can be positioned, An illumination device for illuminating the biological features in the recording volume, The illumination device is configured to project a sequence of at least one image onto the biological feature in order to illuminate the biological feature. Lighting devices and An image recording device for recording the biological features illuminated by the illumination device based on the at least one sequence of projected images, A computing unit, To match at least one of the records of the biometric features recorded based on the projected image of the at least one sequence of projected images with further records of the biometric features based on the at least one sequence of projected images, Calculating the biological data based on the at least one consistent record of the biological characteristics. A computing unit configured to do so and A device equipped with the following features.