Identification methods, devices, computer equipment and storage media

Abstract

This application relates to an identification method, apparatus, computer equipment, storage medium, and computer program product, belonging to the field of artificial intelligence technology. The method includes: acquiring a preset number of first speckle interferograms of the object to be identified at a first target time; acquiring a preset number of second speckle interferograms of the object to be identified at a second target time; determining the interference phase change diagram of the object to be identified from the first target time to the second target time based on each of the first and second speckle interferograms; determining a first liveness detection result of the object to be identified based on the interference phase change diagram; if the first liveness detection result indicates that the object to be identified is alive, acquiring an image of the object to be identified to obtain a matching image, and performing identity recognition processing based on the matching image to obtain the identity recognition result of the object to be identified. This solution improves recognition accuracy.

Description

Technical Field

[0001] This application relates to the field of artificial intelligence technology, and in particular to a recognition method, apparatus, computer device, and storage medium. Background Technology

[0002] With the development of artificial intelligence technology, recognition technology has emerged. This technology can identify the identity of an object and obtain a corresponding identity recognition result. This technology is commonly used in the field of facial recognition to determine the identity information or legitimacy of the object to be identified. The identity recognition result includes either a successful recognition result or a failed recognition result.

[0003] Traditional identification techniques involve acquiring an image of the object to be identified using an image acquisition device. Then, a target reference image is selected from a pre-set image library to match the object. If no target reference image is found, the identification result indicating a failure is used as the identification result for the object. Alternatively, if a target reference image is found, the identification result indicating a success is used as the identification result for the object.

[0004] However, in real-world identification scenarios, existing identification technologies cannot distinguish whether the object to be identified is the object itself, a photograph of the object, or a spoofed model of the object. This allows others to use the photograph or spoofed model of the object to obtain a successful identification result, thereby reducing the accuracy of the identification. Summary of the Invention

[0005] Therefore, it is necessary to provide an identification method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can improve identification accuracy in response to the above-mentioned technical problems.

[0006] Firstly, this application provides an identification method. The method includes:

[0007] At the first target time, a preset number of first speckle interferograms of the object to be identified are acquired, and the two adjacent first speckle interferograms are separated by a preset phase.

[0008] At the second target time, the preset number of second speckle interferograms of the object to be identified are acquired, and the preset phase difference is between two adjacent second speckle interferograms;

[0009] Based on each of the first speckle interferograms and each of the second speckle interferograms, determine the interference phase change pattern of the object to be identified from the first target time to the second target time;

[0010] Based on the interference phase change diagram, the first liveness detection result of the object to be identified is determined;

[0011] If the first liveness detection result indicates that the object to be identified is a live object, an image of the object to be identified is acquired to obtain a matching image, and an identity recognition process is performed based on the matching image to obtain the identity recognition result of the object to be identified.

[0012] In one embodiment, each of the first speckle interferograms includes a first reference interferogram; each of the second speckle interferograms includes a second reference interferogram; determining the interference phase change pattern of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms includes:

[0013] Based on each of the first speckle interferograms, determine the first interference phase diagram of the first reference interferogram;

[0014] Based on each of the second speckle interferograms, a second interference phase diagram of the second reference interferogram is determined; the incident light corresponding to the first reference interferogram is the same as the incident light corresponding to the second reference interferogram; the incident light is light that has not been reflected by the object to be identified and is incident on the image acquisition device;

[0015] Based on the first interference phase diagram and the second interference phase diagram, the interference phase change diagram of the object to be identified from the first target time to the second target time is determined.

[0016] In one embodiment, determining the first liveness detection result of the object to be identified based on the interference phase change map includes:

[0017] Obtain at least one interference circle center in the interference phase change diagram;

[0018] Based on the position information of the interference center, the interference phase change map is partitioned to obtain a partitioned interference phase change map, wherein the partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains one interference center;

[0019] Based on the interference phase change diagram after partitioning, the first liveness detection result of the object to be identified is determined.

[0020] In one embodiment, determining the first liveness detection result of the object to be identified based on the partitioned interference phase change map includes:

[0021] Obtain the number of interference circle centers and the relative positions of the interference circle centers in the interference phase change diagram;

[0022] By comparing the number of interference circle centers in the interference phase change diagram with a preset number, a number comparison result is obtained;

[0023] If the number comparison result indicates that the number of interference centers is the same as the preset number, the relative position of the interference centers is compared with the preset relative position to obtain the position comparison result;

[0024] Based on the location comparison results, the first liveness detection result of the object to be identified is determined.

[0025] In one embodiment, determining the first liveness detection result of the object to be identified based on the partitioned interference phase change map includes:

[0026] Based on the relative positions of the interference circle centers contained within the interference phase change regions, the feature category corresponding to each interference phase change region is determined;

[0027] For any of the interference phase change regions, the range of phase change corresponding to the interference phase change region is determined according to the feature category corresponding to the interference phase change region;

[0028] For any of the aforementioned interference phase change regions, the actual phase change amount corresponding to the interference phase change region is obtained, and it is determined whether the actual phase change amount belongs to the range of the phase change amount, thereby obtaining the determination result corresponding to the interference phase change region.

[0029] Based on the judgment result corresponding to at least one of the interference phase change regions, the first liveness detection result of the object to be identified is determined.

[0030] In one embodiment, determining the feature category corresponding to each interference phase change region based on the relative position of the interference circle centers contained within the interference phase change region includes:

[0031] Obtain the number of interference circle centers and the relative positions of the interference circle centers in the interference phase change diagram;

[0032] When the number of interference circle centers in the interference phase change diagram is the same as the preset number, and the relative positions of the interference circle centers in the interference phase change diagram are the same as the preset relative positions, the feature category corresponding to each interference phase change region is determined according to the relative positions of the interference circle centers contained in each interference phase change region.

[0033] In one embodiment, the method further includes:

[0034] If the first liveness detection result indicates that the object to be identified is not a live object, an action guidance prompt message is issued, and an action image of the object to be identified is captured;

[0035] The second liveness detection result is determined based on the motion image and the preset motion feature data corresponding to the preset specified motion contained in the motion guidance prompt message;

[0036] If the second liveness detection result indicates successful identification, an image of the object to be identified is acquired to obtain a matching image, and identity recognition processing is performed based on the matching image to obtain the identity recognition result of the object to be identified.

[0037] Secondly, this application also provides an identification system. The identification system includes a controller, an image acquisition unit, and a laser generator, wherein:

[0038] The controller is configured to respond to an identification command, control the laser generator to generate coherent light, and send a first image acquisition command to the image acquisition device. The first image acquisition command is configured to instruct the image acquisition device to acquire images at a first target time and a second target time.

[0039] The image acquisition device is configured to, in response to the first image acquisition command, acquire a preset number of first speckle interferograms of the object to be identified at the first target time, and acquire the preset number of second speckle interferograms of the object to be identified at the second target time, and feed back the first speckle interferograms and the second speckle interferograms to the controller; there is a preset phase difference between two adjacent first speckle interferograms; there is a preset phase difference between two adjacent second speckle interferograms.

[0040] The controller is configured to determine the interference phase change map of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms, determine the first liveness detection result of the object to be identified based on the interference phase change map, and control the laser generator to generate structured light and send a second image acquisition command to the image acquisition device when the first liveness detection result indicates that the object to be identified is a live body.

[0041] The image acquisition device is used to acquire an image of the object to be identified in response to the second image acquisition command, obtain an image to be matched, and feed back the image to be matched to the controller;

[0042] The controller is used to perform identity recognition processing based on the image to be matched, and obtain the identity recognition result of the object to be identified.

[0043] In one embodiment, the identification system further includes a first switch and a second switch. The laser generating device includes a laser, a beam splitter, a speckle generation unit, and a structured light generation filter. The first switch is disposed in the first output optical path of the beam splitter, and the second switch is disposed in the second output optical path of the beam splitter, wherein:

[0044] The controller is configured to respond to the identity recognition command by controlling the first switch to open and the second switch to close, and to control the laser to generate target laser.

[0045] The beam splitter is used to split the target laser into a first target laser and a second target laser;

[0046] The first switch is used to allow the first target laser to be incident on the speckle generation unit when the first switch is turned on;

[0047] The second switch is used to prevent the second target laser from being incident on the structured light generating filter when the second switch is closed;

[0048] The speckle generation unit is used to expand the first target laser beam to obtain an expanded first target laser beam, and to split the expanded first target laser beam to obtain a first correlated light and a second correlated light, wherein the expanded first target laser beam is not reflected by the object to be identified.

[0049] In one embodiment, the identification system includes:

[0050] The controller is configured to, when the first liveness detection result indicates that the object to be identified is a live body, control the first switch to close and the second switch to open, and control the laser to generate target laser;

[0051] The first switch is used to prevent the first target laser from being incident on the speckle generation unit when the first switch is closed;

[0052] The second switch is used to allow the second target laser to be incident on the structured light generating filter when the second switch is turned on;

[0053] The structured light generating filter is used to generate the structured light based on the incident second target laser.

[0054] Thirdly, this application also provides an identification device. The device includes:

[0055] The first acquisition module is used to acquire a preset number of first speckle interferograms of the object to be identified at the first target time, wherein the two adjacent first speckle interferograms are separated by a preset phase.

[0056] The second acquisition module is used to acquire the preset number of second speckle interferograms of the object to be identified at the second target time, wherein the preset phase difference exists between two adjacent second speckle interferograms.

[0057] The determining module is used to determine the interference phase change pattern of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms;

[0058] The first liveness detection module is used to determine the first liveness detection result of the object to be identified based on the interference phase change diagram.

[0059] The identity recognition module is used to acquire an image of the object to be identified when the first liveness recognition result indicates that the object to be identified is a live object, to obtain a matching image, and to perform identity recognition processing based on the matching image to obtain the identity recognition result of the object to be identified.

[0060] Fourthly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps described in the first aspect.

[0061] Fifthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps described in the first aspect.

[0062] Sixthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, performs the steps described in the first aspect.

[0063] The aforementioned identification method, apparatus, computer equipment, storage medium, and computer program product acquire a preset number of first speckle interferograms of the object to be identified at a first target time, with a preset phase difference between adjacent first speckle interferograms; at a second target time, acquire the preset number of second speckle interferograms of the object to be identified, with the preset phase difference between adjacent second speckle interferograms; determine the interference phase change map of the object to be identified from the first target time to the second target time based on each of the first and second speckle interferograms; determine a first liveness detection result of the object to be identified based on the interference phase change map; if the first liveness detection result indicates that the object to be identified is alive, acquire an image of the object to be identified to obtain a matching image, and perform identity recognition processing based on the matching image to obtain the identity recognition result of the object to be identified. In the above method, the interference phase change map of the object to be identified is determined based on each of the first speckle interferograms acquired at the first target time and each of the second speckle interferograms acquired at the second target time, and then the object to be identified is determined to be alive based on the interference phase change map. The identification result is determined only when the object to be identified is a living person, based on the image to be matched. Therefore, this method can identify whether the object to be identified is a living person, thereby reducing the possibility of successful identification by using a photograph or a spoof model of the object to impersonate the actual object, and thus improving the identification accuracy. Attached Figure Description

[0064] Figure 1 This is a diagram illustrating the application environment of the identification method in one embodiment;

[0065] Figure 2 This is a diagram illustrating the application environment of the identification method in another embodiment;

[0066] Figure 3 This is a flowchart illustrating the identification method in one embodiment;

[0067] Figure 4 This is a flowchart illustrating a method for determining an interference phase change pattern in one embodiment;

[0068] Figure 5 This is a flowchart illustrating a method for determining the first liveness detection result in one embodiment;

[0069] Figure 6 This is a flowchart illustrating the method for determining the first liveness detection result in another embodiment;

[0070] Figure 7 This is a flowchart illustrating the method for determining the first liveness detection result in another embodiment;

[0071] Figure 8 This is a flowchart illustrating a method for determining identity recognition results in one embodiment;

[0072] Figure 9 This is a structural block diagram of the identification device in one embodiment;

[0073] Figure 10 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0075] The identification method provided in this application embodiment can be applied to, for example, Figure 1 The application environment shown. Figure 1 The identification system includes a controller 102, an image acquisition unit 104, and a laser generator. The controller 102 is electrically connected to both the image acquisition unit 104 and the laser generator. The controller 102 is a device with control and data processing functions. The laser generator includes a laser 106, a beam splitter (referred to as the first beam splitter for easy distinction) 108, a speckle generation unit, and a structured light generation filter 110. The speckle generation unit includes a beam expander 112 and a phase shifter 114, which comprises piezoelectric ceramic and a plane mirror. In one embodiment, the identification system further includes a first switch 116, a second switch 118, a first plane mirror 120, a second beam splitter 122, a second plane mirror 124, and a third beam splitter 126. Exemplarily, the controller 102 includes a control unit, a laser control circuit, and a drive circuit. The drive circuit includes an acquisition drive circuit and a phase shifter drive circuit. The phase-shifting mirror driving circuit is electrically connected to the phase-shifting mirror 114, and the phase-shifting mirror driving circuit is used to drive the phase-shifting mirror 114. Figure 1 The connection between the phase shift mirror drive circuit and the phase shift mirror 114 is not shown in the figure. The recognition system may also include a system housing 128, a light-emitting aperture 130, and a light-entry aperture 132, wherein the light-emitting aperture 130 and the light-entry aperture 132 are respectively disposed on the system housing 128.

[0076] Specifically, in response to the identification command, the controller 102 controls the laser generator to produce coherent light and sends a first image acquisition command to the image acquisition device. The first image acquisition command instructs the image acquisition device 104 to acquire images at a first target time and a second target time. Optionally, the first image acquisition command can be a single image acquisition command or include two image acquisition commands (i.e., image acquisition command 1 and image acquisition command 2); where image acquisition command 1 instructs the image acquisition device 104 to acquire images at the first target time, and image acquisition command 2 instructs the image acquisition device 104 to acquire images at the second target time. Specifically, the control unit in the controller 102 sends a laser generation signal to the laser generator 106 through the laser control circuit, and controls the first switch 116 to open and the second switch 118 to close through the laser control circuit. In response to the laser generation signal, the laser generator 106 emits a target laser towards the first beam splitter 108, so that the target laser is split into two beams (i.e., the first target laser and the second target laser) by the first beam splitter 108. In this application, the target laser is a laser that does not stimulate the object to be identified or produces a stimulus less than a preset stimulus level. For example, the target laser is an infrared laser.

[0077] Since the first switch 116 is located in the optical path of the first target laser, when the first switch 116 is open and the second switch 118 is closed, the first target laser is incident on the first plane mirror 120 and reflected by the first plane mirror 120 to the second beam splitter 122, so that the first target laser is split into two beams (i.e., first target laser 1 and first target laser 2) by the second beam splitter 122. The first target laser 1 is incident on the beam expander 112 to obtain the expanded first target laser 1. The expanded first target laser 1 is reflected by the third beam splitter 126 and passes through the light exit aperture 130 to be incident on the object to be identified. The expanded first target laser 1 (i.e., laser speckle) reflected by the object to be identified is incident on the image acquisition unit 104 through the light entrance aperture 132. Among them, the expanded first target laser 1 reflected by the object to be identified is laser speckle. In one embodiment, the target laser is an infrared laser, then the laser speckle is infrared laser speckle. The first target laser 2 is reflected by the second plane mirror 124 to the phase shift mirror 114. The first target laser 2 emitted from the phase shift mirror 114 is incident on the image acquisition unit 104 and interferes with the laser speckle on the image acquisition unit 104.

[0078] The image acquisition unit responds to the first image acquisition command and acquires the first speckle interferogram of the object to be identified at the first target time, and feeds back the first speckle interferogram to the controller 102. The controller 102 receives the first speckle interferogram and counts the number of first speckle interferograms received. If the number of first speckle interferograms received reaches a preset number, the controller 102 controls the image acquisition unit 104 to stop acquiring images of the first speckle interferogram. If the number of first speckle interferograms received does not reach the preset number, the controller 102 controls the image acquisition unit 104 to continue acquiring first speckle interferograms. Specifically, if the number of first speckle interferograms received does not reach the preset number, the controller 102 changes the phase shift parameter in the phase shift mirror 114 through the phase shift mirror driving circuit, so that the phase of the first target laser 2 emitted from the phase shift mirror 114 is different each time, thereby making the two speckle interferograms (including the first speckle interferogram or the second speckle interferogram) differ by a preset phase. It can be understood that the acquisition of the first speckle interferogram needs to be completed at the first target time. The acquisition process of the second speckle interferogram is similar to that of the first speckle interferogram, and will not be repeated here. The difference between the two is that the timing of acquiring the speckle interferogram is different.

[0079] The controller 102 determines the interference phase change diagram of the object to be identified from the first target time to the second target time based on each of the first and second speckle interferograms. Based on the interference phase change diagram, the controller 102 determines the first liveness detection result of the object to be identified. If the first liveness detection result indicates that the object to be identified is alive, the controller 102 controls the laser generator to generate structured light and sends a second image acquisition command to the image acquisition unit 104. Specifically, the control unit in the controller 102 sends a laser generation signal to the laser generator 106 through the laser control circuit, and controls the first switch 116 to close and the second switch 118 to open through the laser control circuit. In response to the laser generation signal, the laser generator 106 emits a target laser towards the first beam splitter 108, so that the target laser is split into two beams (i.e., the first target laser and the second target laser) by the first beam splitter 108.

[0080] Since the second switch is located in the optical path of the second target laser, when the first switch 116 is closed and the second switch 118 is open, the second target laser is incident on the structured light filter 110. The second target laser passing through the structured light generation filter 110 carries the structural information from the structured light generation filter 110; therefore, the structured light emitted from the structured light generation filter 110 is structured light. The structured light reflected by the object to be identified is incident on the image acquisition unit 104. Responding to the second image acquisition command, the image acquisition unit 104 acquires an image of the object to be identified, obtains the image to be matched, and feeds back the image to be matched to the controller 102. The controller 102 performs identity recognition processing based on the image to be matched to obtain the identity recognition result of the object to be identified.

[0081] The identification method provided in this application embodiment can also be applied to, for example, Figure 2 The application environment shown. Figure 2 The identification system includes a controller 102, an image acquisition unit 104, and a laser generator. The laser generator includes a correlation light generator and a structured light generator 202, and the coherent light generator includes a beam expander laser generator 204 and a phase shifter mirror 114. The identification system also includes a fourth beam splitter 206 and a third plane mirror 208.

[0082] Specifically, in response to the identification command, the controller 102 controls the beam expander laser generator 204 to generate a beam expander target laser and sends a first image acquisition command to the image acquisition unit 104. Specifically, the control unit in the controller 102 sends a beam expander laser generation signal to the beam expander laser generator 204 via a laser control circuit. In response to the beam expander laser generation signal, the laser generator 106 generates a beam expander target laser and emits it to the fourth beam splitter 206, so that the beam expander target laser is split into two beams (i.e., a first beam expander target laser and a second beam expander target laser). The beam expander target laser used in this application is a laser that does not stimulate the object to be identified or produces a stimulus less than a preset stimulus level; for example, the beam expander target laser is an infrared laser. The first beam expander target laser is incident on the object to be identified through the exit aperture 130, and the first beam expander target laser (i.e., laser speckle) reflected by the object to be identified is incident on the image acquisition unit 104 through the entrance aperture 132. In this embodiment, the first expanded target laser beam reflected by the object to be identified is laser speckle. In one embodiment, the expanded target laser beam is an infrared laser, then the laser speckle is infrared laser speckle.

[0083] The second expanded target laser beam is reflected by the third plane mirror 208 to the phase shift mirror 114. The second expanded target laser beam emitted from the phase shift mirror 114 is incident on the image acquisition unit 104 and interferes with the laser speckle pattern at the image acquisition unit 104. The image acquisition unit 104 responds to the first image acquisition command and acquires the first speckle interferogram of the object to be identified at the first target time, and feeds back the first speckle interferogram to the controller 102. The controller 102 receives the first speckle interferogram and counts the number of received first speckle interferograms. If the number of received first speckle interferograms reaches a preset number, the controller 102 controls the image acquisition unit 104 to stop acquiring images of the first speckle interferograms. If the number of received first speckle interferograms does not reach the preset number, the controller 102 controls the image acquisition unit 104 to continue acquiring first speckle interferograms. Specifically, if the number of received first speckle interferograms has not reached a preset number, the controller 102 changes the phase shift parameter in the phase shift mirror 114 through the phase shift mirror drive circuit, so that the phase of the first target laser 2 emitted from the phase shift mirror 114 is different each time, thereby making the two speckle interferograms (including the first speckle interferogram or the second speckle interferogram) differ by a preset phase. It can be understood that the acquisition of the first speckle interferogram needs to be completed at the first target time. The acquisition process of the second speckle interferogram is similar to that of the first speckle interferogram, and will not be described again; the difference lies in the timing of the speckle interferogram acquisition.

[0084] The controller 102 determines the interference phase change diagram of the object to be identified from the first target time to the second target time based on each of the first and second speckle interferograms. Based on the interference phase change diagram, the controller 102 determines the first liveness detection result of the object to be identified. If the first liveness detection result indicates that the object to be identified is alive, the controller 102 controls the laser generator to generate structured light and sends a second image acquisition command to the image acquisition unit 104. The control unit in the controller 102 sends a structured light generation signal to the structured light generator 202 through the laser control circuit. The structured light generator 202, in response to the structured light generation signal, generates structured light and emits it to the object to be identified. The structured light reflected by the object to be identified is directly incident on the image acquisition unit 104. The control unit in the controller 102 sends a second image acquisition command to the image acquisition unit 104 through the acquisition drive circuit. In response to the second image acquisition command, the image acquisition unit 104 acquires an image of the object to be identified, obtains the image to be matched, and feeds back the image to be matched to the controller 102. The controller 102 performs identity recognition processing on the image to be matched to obtain the identity recognition result of the object to be identified.

[0085] In one embodiment, such as Figure 3 As shown, an identification method is provided, which is applied to... Figure 1 or Figure 2 Taking the recognition system in the image as an example, the following steps are included:

[0086] Step 302: At the first target time, a preset number of first speckle interferograms of the object to be identified are acquired.

[0087] The two adjacent first speckle interferograms are separated by a preset phase.

[0088] In this embodiment, at a first target time, the image acquisition unit 104 acquires a preset number of first speckle interferograms of the object to be identified using speckle interferometry and time phase shifting techniques. The first target time can be the moment the object to be identified (including a face) is detected, or the moment an authentication command is received. Optionally, the first target time is a random moment when the image acquisition unit 104 starts acquiring the first speckle interferograms in response to a first image acquisition command. Optionally, the time phase shifting technique can be a three-step time phase shifting technique, a four-step time phase shifting technique, or a five-step time phase shifting technique. Taking a four-step time phase shifting technique as an example, if the time phase shifting technique is four steps, the preset number is 4, the preset phase is π / 2, and the light intensity data in the four first speckle interferograms are as shown in formula (1).

[0089] Formula (1)

[0090] in, This indicates the position information of the pixel on the first speckle interferogram (or the second speckle interferogram). Indicates the first The first speckle interferogram (or the second speckle interferogram) pixels The light intensity, of which, the first =1, 2, 3, 4, This represents the first speckle interferogram (or the second speckle interferogram) in... Background light intensity of pixels, This represents the first speckle interferogram (or the second speckle interferogram) in... The modulation of background light intensity of pixels. This represents the first speckle interferogram (or the first second speckle interferogram) in... Interference phase of pixels. and This represents the first adjacent speckle interferogram (or the second speckle interferogram).

[0091] Step 304: At the second target time, acquire the preset number of second speckle interferograms of the object to be identified.

[0092] The two adjacent second speckle interferograms differ by the preset phase.

[0093] In this embodiment, at the second target time, the image acquisition unit 104 acquires a preset number of second speckle interferograms of the object to be identified using speckle interferometry and time phase shifting techniques. It is understood that the method for acquiring the second speckle interferograms is similar to the method for acquiring the first speckle interferogram, and can be referred to step 302, which will not be repeated here. The second target time can be any time after the first target time, for example, a time interval of a preset duration from the first target time.

[0094] Step 306: Based on each of the first speckle interferograms and each of the second speckle interferograms, determine the interference phase change pattern of the object to be identified from the first target time to the second target time.

[0095] In this embodiment, the controller 102 determines the interference phase change map of the object to be identified from the first target time to the second target time based on each first speckle interferogram and each second speckle interferogram. The interference phase change map characterizes the change in interference phase of the object to be identified from the first target time to the second target time, and the interference phase includes the phase corresponding to each pixel in the first speckle interferogram (or the second speckle interferogram). It can be understood that the interference phase change map from the first target time to the second target time refers to a single interference phase change map, and the interference phase in this map characterizes the change in interference phase of the laser speckle from the first target time to the second target time, as shown in formula (2) below.

[0096] Formula (2)

[0097] in, It is in the interference phase change diagram The interference phase of the pixels, i.e. This represents the change in the interference phase of the laser speckle from the first target time to the second target time. It is the first interference phase diagram Interference phase of pixels It is the second interference phase diagram Interference phase of pixels It is the wavelength of the laser speckle (or the first target laser 1 after beam expansion). From the first target time to the second target time The path difference of the laser speckle reflected from the pixel. For the acquisition method and meaning of the first interference phase image, please refer to step 402; for the acquisition method and meaning of the second interference phase image, please refer to step 404.

[0098] Step 308: Determine the first liveness detection result of the object to be identified based on the interference phase change diagram.

[0099] The first liveness detection result includes either a first liveness detection result indicating that the object to be identified is a live object, or a first liveness detection result indicating that the object to be identified is a non-live object. The interference phase change map includes the position information of any pixel in the interference phase change map, the interference phase of any pixel, and the interference light intensity of any pixel. The interference light intensity corresponding to a pixel in the interference phase change map is used to characterize the change in interference light intensity of the pixel from the first target time to the second target time. For example, the interference phase change map is a three-dimensional image, where the horizontal and vertical axes of the three-dimensional image represent the position information of the pixel in the interference phase change map, the interference phase of any pixel, and the interference light intensity of any pixel. The data corresponding to the axis represents the interference phase of the pixel in the interference phase change diagram, and the pixel value corresponding to the pixel represents the interference light intensity of the pixel.

[0100] In this embodiment, the controller 102 analyzes the interference phase in the interference phase change diagram to obtain the analysis result, and determines whether the object to be identified is a living body based on the analysis result. If the object to be identified is a living body, the controller 102 generates a first liveness detection result indicating that the object to be identified is a living body. Alternatively, if the object to be identified is not a living body, the controller 102 generates a first liveness detection result indicating that the object to be identified is not a living body.

[0101] Step 310: If the first liveness detection result indicates that the object to be identified is a live object, an image of the object to be identified is acquired to obtain a matching image, and an identity recognition process is performed based on the matching image to obtain the identity recognition result of the object to be identified.

[0102] The identity recognition result includes either a successful identity recognition result or a failed identity recognition result.

[0103] In this embodiment of the application, when the first liveness detection result indicates that the object to be identified is a live object, the image acquisition device 104 acquires an image of the object to be identified, obtains a matching image, and sends the matching image to the controller 102. Specifically, as shown... Figure 1As shown, controller 102 controls a laser generator to generate an infrared structured light beam. The infrared structured light reflected by the object to be identified is incident on image acquisition unit 104, which acquires the matching image of the object to be identified. Controller 102 performs identity recognition processing based on the matching image and a preset image library to obtain the identity recognition result of the object to be identified, and displays the identity recognition result on a display device. The preset image library includes at least one reference image, which is used to determine whether the object to be identified to which the matching image belongs is an object that has completed identification and authentication, or whether it is a whitelisted object. The object corresponding to the reference image can be an object that has completed identification and authentication, or a whitelisted object pre-stored in the preset image library. In one embodiment, controller 102 first calculates the image precision of the matching image. If the image precision of the matching image does not meet the preset precision requirement, controller 102 controls image acquisition unit 104 to acquire a new matching image of the object to be identified. This process continues until the image precision of the new matching image meets the preset precision requirement, at which point identity recognition processing is performed based on the matching image that meets the preset precision requirement.

[0104] In the aforementioned identification method, the interference phase change map of the object to be identified is determined based on the first speckle interferograms acquired at the first target time and the second speckle interferograms acquired at the second target time. Then, the liveness of the object is determined based on the interference phase change map. Only when the object is confirmed to be live is the identification result determined based on the matching image of the object. Therefore, this method can identify whether the object is live, thereby reducing the likelihood of successful identification by using a photograph or a spurious model of the object to impersonate it, thus improving identification accuracy.

[0105] In one embodiment, such as Figure 4 As shown, each of the first speckle interferograms includes a first reference interferogram; each of the second speckle interferograms includes a second reference interferogram; the step of determining the interference phase change pattern of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms includes:

[0106] Step 404: Determine the first interference phase diagram of the first reference interferogram based on each of the first speckle interferograms.

[0107] In this embodiment, the controller 102 obtains a first reference interferogram from each of the first speckle interferograms. Specifically, a selection strategy for the first reference interferogram can be preset in the controller 102. For example, a selection strategy for the first reference interferogram can be preset in the controller 102. The first speckle interferogram is the first reference interferogram. are positive integers and A preset number is specified. In one embodiment, the controller 102 uses the first speckle interferogram as the first reference interferogram. The controller 102 performs image phase unwrapping processing on the first reference interferogram to obtain a first interference phase map. In another embodiment, the controller 102 first performs image filtering on the first reference interferogram to obtain a filtered first reference interferogram, and then performs image phase unwrapping processing on the filtered first reference interferogram to obtain a first interference phase map.

[0108] Step 406: Determine the second interference phase pattern of the second reference interferogram based on each of the second speckle interferograms.

[0109] The incident light corresponding to the first reference interferogram is the same as the incident light corresponding to the second reference interferogram. The incident light is light that has not been reflected by the object to be identified and is incident on the image acquisition device. It can be understood that the incident light corresponding to the first reference interferogram is the light emitted from the phase shift mirror 114 (including the first target laser 2 or the second expanded target laser).

[0110] In this embodiment, the controller 102 obtains a second reference interferogram from each of the second speckle interferograms. Specifically, a selection strategy for the second reference interferogram can be preset in the controller 102. For example, a selection strategy for the second reference interferogram can be preset in the controller 102. The second speckle interferogram is the second reference interferogram. are positive integers and A preset number is specified. In one embodiment, the controller 102 uses the first second speckle interferogram as the second reference interferogram. The controller 102 performs image phase unwrapping processing on the second reference interferogram to obtain a second interferometric phase map. In another embodiment, the controller 102 first performs image filtering on the second reference interferogram to obtain a filtered second reference interferogram, and then performs image phase unwrapping processing on the filtered second reference interferogram to obtain a second interferometric phase map.

[0111] Step 408: Based on the first interference phase diagram and the second interference phase diagram, determine the interference phase change diagram of the object to be identified from the first target time to the second target time.

[0112] In this embodiment, the controller 102 calculates the difference between the first interference phase diagram and the second interference phase diagram, as shown in the above formula (2), and uses the difference between the first interference phase diagram and the second interference phase diagram as the interference phase change diagram of the object to be identified from the first target time to the second target time. It can be understood that since the light emitted from the phase shift mirror 114 corresponding to the first reference interferogram is the same as the light emitted from the phase shift mirror 114 corresponding to the second reference interferogram, the interference phase change diagram... The reason why the interference phase value of a pixel is not 0 is that the laser speckle corresponding to the first reference interferogram (i.e., the first target laser 1 after beam expansion reflected by the object to be identified, or the target laser after beam expansion) is different from the laser speckle corresponding to the second reference interferogram. Since the identification system has not changed, the change in laser speckle is caused by the displacement of the object to be identified. Therefore, it can be roughly estimated that the object to be identified is a living object. In other words, if the interference phase change diagram... If the interference phase value of all pixels is 0, then the object to be identified is a non-living object.

[0113] In this embodiment, an interference phase change map is determined based on the first interference phase map of the first reference interferogram and the second interference phase map of the second reference interferogram, thereby providing data support for subsequent determination of whether the object to be identified is a living body based on the interference phase change map.

[0114] In one embodiment, such as Figure 5 As shown, based on the interference phase change diagram, the first liveness detection result of the object to be identified is determined, including:

[0115] Step 502: Obtain at least one interference circle center in the interference phase change diagram.

[0116] In this embodiment, the controller 102 extracts the interference center from the interference phase change map of the object to be identified. This application does not limit the method for extracting the interference center; all methods capable of extracting the interference center are within the protection scope of this application. For example, the controller 102 obtains pixels with the same interference intensity from the interference phase change map, resulting in at least one pixel group. For any pixel group, the controller 102, based on the position information of each pixel within the pixel group in the interference phase change map, groups pixels that fit into the same circular curve into the same target pixel group, resulting in at least one target pixel group. The target pixel group contains multiple target pixels, and the target pixels in the same target pixel group have the same interference intensity, and the position information of each target pixel in the same target pixel group can be fitted into a circular curve. For any target pixel group, the controller 102 calculates whether a certain pixel exists in the interference phase change map (assuming it is a target pixel) based on the position data of each target pixel within the target pixel group. If the distance to each target pixel in the pixel group is the same, then the controller 102 will... The point is used as the center of the interference circle. Specifically, it is shown in formula (3) below.

[0117] Formula (3)

[0118] in, express The position information (i.e., coordinates) of the point in the interferometric phase change diagram. express The position information (i.e., coordinates) of the point in the interferometric phase change diagram. The point represents the first pixel in the target pixel group. Target pixels, It is a positive integer. The maximum value is the number of target pixels included in the target pixel group.

[0119] Step 504: Based on the position information of the interference center, the interference phase change map is partitioned to obtain the partitioned interference phase change map.

[0120] The partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains one interference center. It can be understood that the number of interference phase change regions is equal to the number of interference centers.

[0121] In this embodiment, the controller 102 partitions each pixel in the interference phase change map according to the position information of the interference center in the interference phase change map, resulting in a partitioned interference phase change map. Each pixel in the partitioned interference phase change map has a corresponding interference phase change region. For example, for any target pixel group in the interference phase change map, the controller 102 divides each target pixel in the target pixel group and the corresponding interference center into the same interference phase change region. If there are pixels in the interference phase change map that do not have a corresponding target pixel group (for convenience, referred to as ungrouped pixels), then for any ungrouped pixel, the controller 102 takes the target pixel group of the target pixel closest to the ungrouped pixel as the target pixel group of that ungrouped pixel.

[0122] Step 506: Determine the first liveness detection result of the object to be identified based on the interference phase change diagram after partitioning.

[0123] In this embodiment of the application, the controller 102 determines the first liveness detection result of the object to be identified based on the number of interference circles and / or the position information of the interference circles and / or the feature category corresponding to the interference phase change region in the partitioned interference phase change map.

[0124] In this embodiment, the interference phase change map is partitioned based on the position information of the interference center, resulting in a partitioned interference phase change map. Then, the first liveness detection result is determined based on the partitioned interference phase change map. In other words, this method can not only roughly estimate whether the object to be identified is alive based on the interference phase in the interference phase change map, but also further determine whether the object is alive based on the information contained in the partitioned interference phase change map, thus further improving the accuracy of liveness detection.

[0125] In one embodiment, such as Figure 6 As shown, based on the interference phase change diagram after partitioning, the first liveness detection result of the object to be identified is determined, including:

[0126] Step 602: Obtain the number of interference circles and their relative positions in the interference phase change diagram.

[0127] In this embodiment, the controller 102 counts the number of interference centers in the interference phase change diagram and determines the relative positions of the interference centers based on their positions in the diagram. The relative positions of the interference centers are used to characterize the relative positions between them. In one embodiment, the controller 102 can characterize the relative positions of the interference centers by adding relative position identifiers. These relative positions include, but are not limited to, top left, bottom left, top right, bottom right, top left one (i.e., the first interference center from left to right in the top left region of another interference center (or interference phase change diagram), and bottom right two (i.e., the second interference center from left to right in the bottom right region of another interference center (or interference phase change diagram). For example, assuming the interference centers include interference center 1 (0,0), interference center 2 (10,2), interference center 3 (0,9), and interference center 4 (9,11), then the relative position of interference center 1 is lower left, the relative position of interference center 2 is lower right, the relative position of interference center 3 is upper left, and the relative position of interference center 4 is upper right. If there is only one interference center in the interference phase change diagram, the relative position of the interference center is used to characterize the region of the interference center in the interference phase change diagram. The region in the interference phase change diagram can be divided according to a pre-set image position region division strategy. For example, the controller 102 divides the interference phase change diagram into equal parts... There are several regions, among which... It is a positive integer. Specifically, if there is only one interference center in the interference phase change diagram, the relative position of the interference center is used to characterize the position of the interference center in the interference phase change diagram. area.

[0128] Step 604: Compare the number of interference circle centers in the interference phase change diagram with a preset number to obtain the number comparison result.

[0129] In this embodiment, the controller 102 compares the number of interference circle centers in the interference phase change diagram with a preset number to obtain a number comparison result. The preset number is determined based on the number of sample interference circle centers in each sample interference phase change diagram. The sample identification object and the object to be identified corresponding to the sample interference phase change diagram are of the same object type; for example, both the sample identification object and the object to be identified are humans. Optionally, the number comparison result can be used to characterize whether the number of interference circle centers is the same as the preset number, or it can be used to characterize the absolute value of the difference between the number of interference circle centers and the preset number. If the number comparison result indicates that the number of interference circle centers is different from the preset number, the controller 102 generates a first liveness detection result indicating that the object to be identified is not a living body, and executes step 802.

[0130] Step 606: If the number comparison result indicates that the number of interference centers is the same as the preset number, compare the relative position of the interference centers with the preset relative position to obtain the position comparison result.

[0131] In this embodiment, when the number comparison result indicates that the number of interference centers is the same as the preset number, the controller 102 compares the relative positions of each interference center with the preset relative positions to obtain a position comparison result. The preset relative positions are determined based on the relative positions of the sample interference centers in each sample interference phase change diagram. Optionally, the position comparison result can be used to characterize whether the relative positions of all interference centers are the preset relative positions (i.e., the relative positions of the interference centers are the same as the preset relative positions), or it can be used to characterize how many interference centers have the preset relative positions.

[0132] Step 608: Based on the location comparison result, determine the first liveness detection result of the object to be identified.

[0133] In this embodiment, if the position comparison result indicates that the relative position of the interference circle center is the same as the preset relative position, the controller 102 generates a first liveness detection result indicating that the object to be identified is a living body, and executes step 310. If the position comparison result indicates that the relative position of the interference circle center is not the same as the preset relative position, the controller 102 generates a first liveness detection result indicating that the object to be identified is not a living body, and executes step 802. The first liveness detection result is used to characterize whether the object to be identified is a living body.

[0134] In this embodiment, the liveness of the object to be identified is determined by the number and relative positions of the interference centers in the interference phase change diagram. In other words, this method can not only roughly estimate whether the object is alive based on the interference phase in the interference phase change diagram, but also further determine its liveness based on the number and relative positions of the interference centers. Therefore, this method can further improve the accuracy of liveness detection for the object to be identified.

[0135] In one embodiment, such as Figure 7 As shown, determining the first liveness detection result of the object to be identified based on the interference phase change map after partitioning includes:

[0136] Step 702: Determine the feature category corresponding to each interference phase change region based on the relative position of the interference circle center contained in the interference phase change region.

[0137] In this embodiment, for any interference phase change region, the controller 102 determines the feature category corresponding to the interference phase change region based on the relative positions of the interference circle centers contained within the interference phase change region and a preset correspondence between relative positions and feature categories. The feature category is determined based on the object type corresponding to the object to be identified. For example, when the object type corresponding to the object to be identified is a person, the feature categories include, but are not limited to, eyes, ears, mouth, and nose. The correspondence between relative positions and feature categories is determined based on the feature categories corresponding to the relative positions in the interference phase change maps of each sample.

[0138] Step 704: For any of the interference phase change regions, determine the range of phase change amount corresponding to the interference phase change region based on the feature category corresponding to the interference phase change region.

[0139] In this embodiment, for any interference phase change region, the controller 102 determines the phase change range corresponding to the interference phase change region based on the feature category corresponding to the interference phase change region and the preset correspondence between the feature category and the phase change range. The correspondence between the feature category and the phase change range is determined based on the interference phase corresponding to the feature category in each sample interference phase change map. The phase change range includes a comprehensive phase change range or an out-of-plane change range.

[0140] Step 706: For any of the interference phase change regions, obtain the actual phase change amount corresponding to the interference phase change region, and determine whether the actual phase change amount belongs to the range of the phase change amount, thereby obtaining the judgment result corresponding to the interference phase change region.

[0141] In this embodiment, for any interference phase change region, the controller 102 calculates the average of the sums of the interference phases corresponding to each pixel within the interference phase change region to obtain the actual phase change amount corresponding to the interference phase change region. For any interference phase change region, the controller 102 determines whether the actual phase change amount matches the range of the comprehensive phase change amount, obtaining a judgment result corresponding to the interference phase change region. Specifically, the controller 102 determines whether the actual phase change amount belongs to the range of the comprehensive phase change amount. If the actual phase change amount belongs to the range of the comprehensive phase change amount, the controller 102 generates a judgment result indicating that the actual phase change amount matches the phase change amount range; or, if the actual phase change amount does not belong to the range of the comprehensive phase change amount, the controller 102 generates a judgment result indicating that the actual phase change amount does not match the phase change amount range.

[0142] In another embodiment, for any interference phase change region, the controller 102 calculates the average of the sum of the out-of-plane phases corresponding to each pixel point in the interference phase change region to obtain the actual phase change amount corresponding to the interference phase change region, specifically as shown in the following formula (4).

[0143] Formula (4)

[0144] in, It is in the interference phase change diagram The interference phase of the pixels, i.e. This represents the change in the interference phase of the laser speckle from the first target time to the second target time. It is the first interference phase diagram Interference phase of pixels It is the second interference phase diagram Interference phase of pixels It is the wavelength of the laser speckle (or the first target laser 1 after beam expansion). The angle (less than or equal to 90°) between the light (including the first target laser 2) emitted from the phase shift mirror 114 and incident on the image acquisition unit 104 and the optical axis of the image acquisition unit 104. The value is pre-stored in the recognition system. This indicates the time from the first target time to the second target time. Laser speckle reflected from pixels Path difference on the axis, i.e. The out-of-plane phase is used to characterize the change in the out-of-plane phase from the first target time to the second target time. This indicates the time from the first target time to the second target time. Laser speckle reflected from pixels shaft and The path difference on the plane formed by the axes, i.e. The plane phase is used to characterize the change in plane phase from the first target time to the second target time. shaft and The plane formed by the axis is on the same plane as the surface of the object to be identified. The axis is perpendicular to shaft and The coordinate axes of the plane formed by the axes. This can be understood because the direction of pulsation of blood vessels under the skin in the microscopic world of a living organism should be... In the axial direction, therefore, compared to mixing of , The numerical value can more accurately reflect whether the object to be identified is a living being.

[0145] For any interference phase change region, the controller 102 determines whether the actual phase change matches the range of out-of-plane changes, thus obtaining a judgment result corresponding to the interference phase change region. Specifically, the controller 102 determines whether the actual phase change falls within the range of out-of-plane changes. If the actual phase change falls within the range of out-of-plane changes, the controller 102 generates a judgment result indicating that the actual phase change matches the phase change range; or, if the actual phase change does not fall within the range of out-of-plane changes, the controller 102 generates a judgment result indicating that the actual phase change does not match the phase change range.

[0146] Step 708: Determine the first liveness detection result of the object to be identified based on the judgment result corresponding to at least one of the interference phase change regions.

[0147] In this embodiment, if there is a judgment result indicating that the actual phase change amount does not match the phase change range, the controller 102 generates a first liveness detection result indicating that the object to be identified is not a living person, and executes step 802. Alternatively, if all judgment results indicate that the actual phase change amount matches the phase change range, the controller 102 generates a first liveness detection result indicating that the object to be identified is a living person, and executes step 310.

[0148] In this embodiment, the liveness of the object to be identified is determined by whether the actual phase change corresponding to the interference phase change region matches the range of phase change. In other words, this method can not only roughly estimate whether the object to be identified is alive based on the interference phase in the interference phase change diagram, but also further determine whether the object is alive based on the actual phase change corresponding to the interference phase change region, thus further improving the accuracy of liveness detection.

[0149] In one embodiment, determining the feature category corresponding to each interference phase change region based on the relative position of the interference circle centers contained within the interference phase change region includes:

[0150] Obtain the number of interference circle centers and their relative positions in the interference phase change diagram; if the number of interference circle centers in the interference phase change diagram is the same as a preset number and the relative positions of the interference circle centers in the interference phase change diagram are the same as a preset relative positions, determine the feature category corresponding to each interference phase change region based on the relative positions of the interference circle centers contained in each interference phase change region.

[0151] In this embodiment, the controller 102 acquires the number of interference circle centers and their relative positions in the interference phase change diagram. Specifically, refer to step 602. The controller 102 executes step 604, comparing the relative positions of the interference circle centers with a preset relative position if the number of interference circle centers in the interference phase change diagram is the same as the preset number. If the relative positions of the interference circle centers in the interference phase change diagram are the same as the preset relative positions, the controller 102 executes step 702. Alternatively, if the relative positions of the interference circle centers in the interference phase change diagram are different from the preset relative positions, the controller 102 generates a first liveness detection result indicating that the object to be identified is not a live body, and executes step 802.

[0152] In this embodiment, the liveness of the object to be identified is determined by considering the number of interference centers, their relative positions, and whether the actual phase change matches the range of phase change in the interference phase change diagram. In other words, this method can not only roughly estimate the liveness of the object based on the interference phase in the interference phase change diagram, but also further determine its liveness by combining the number of interference centers, their relative positions, and the actual phase change. Therefore, this method can further improve the accuracy of liveness detection for the object to be identified.

[0153] In one embodiment, such as Figure 8 As shown, the identification method also includes:

[0154] Step 802: If the first liveness detection result indicates that the object to be identified is not a live object, issue an action guidance prompt message and collect an action image of the object to be identified.

[0155] The control and recognition system also includes a display device.

[0156] In this embodiment, if the first liveness detection result indicates that the object to be identified is not alive, the controller 102 controls the recognition system to generate an action guidance prompt message and displays the action guidance prompt message on the display device. After the action guidance prompt message is displayed on the display device, the controller 102 controls the image acquisition device 104 to acquire an image of the action of the object to be identified.

[0157] Step 804: Determine the second liveness detection result based on the action image and the preset action feature data corresponding to the preset specified action contained in the action guidance prompt message.

[0158] In this embodiment, the controller 102 calculates motion feature data corresponding to the motion image of the object to be identified. The controller 102 determines the motion similarity based on the motion feature data corresponding to the motion image and the preset motion feature data corresponding to a preset specified motion contained in the motion guidance prompt message, and judges the magnitude of the motion similarity compared to a preset similarity threshold. If the motion similarity is greater than or equal to the preset similarity threshold, the controller 102 generates a second liveness detection result indicating that the object to be identified is a live body. Alternatively, if the motion similarity is less than the preset similarity threshold, the controller 102 generates an identity recognition result indicating that the identity recognition of the object to be identified has failed, and displays the identity recognition result to the object to be identified on the display device.

[0159] Step 806: If the second liveness detection result indicates successful detection, an image of the object to be identified is acquired to obtain a matching image, and identity recognition processing is performed based on the matching image to obtain the identity recognition result of the object to be identified.

[0160] In this embodiment, when the second liveness result indicates that the object to be identified is alive, the controller 102 controls the image acquisition device 104 to acquire an image of the object to be identified, obtaining a matching image of the object. The controller 102 performs identity recognition processing based on the matching image and a preset image library to obtain the identity recognition result of the object to be identified, and displays the identity recognition result to the object to be identified on a display device.

[0161] In this embodiment, if the first liveness detection result indicates that the object to be identified is not alive, the motion image of the object to be identified is used to determine whether the object is alive again, resulting in a second liveness detection result. Then, the identity of the object is further determined based on the second liveness detection result. This reduces the error caused by the first liveness detection result determined based on the interference phase change map of the object to be identified, further improving the recognition accuracy.

[0162] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0163] Based on the same inventive concept, this application also provides an identification system for implementing the identification method described above. The solution provided by this system is similar to the implementation scheme described in the above method; therefore, the specific limitations in one or more identification system embodiments provided below can be found in the limitations of the identification method described above, and will not be repeated here.

[0164] In one embodiment, such as Figure 1 or Figure 2 As shown, an identification system is provided, which includes a controller 102, an image acquisition unit 104, and a laser generator, wherein:

[0165] Controller 102 is used to control the laser generator to generate coherent light in response to the identity recognition command, and send a first image acquisition command to image acquisition unit 104. The first image acquisition command is used to instruct image acquisition unit 104 to perform image acquisition at a first target time and a second target time.

[0166] Image acquisition unit 104 is used to respond to a first image acquisition command to acquire a preset number of first speckle interferograms of the object to be identified at a first target time, and to acquire a preset number of second speckle interferograms of the object to be identified at a second target time, and to feed back the first speckle interferograms and second speckle interferograms to controller 102; there is a preset phase difference between two adjacent first speckle interferograms; there is a preset phase difference between two adjacent second speckle interferograms.

[0167] The controller 102 is used to determine the interference phase change diagram of the object to be identified from the first target time to the second target time according to each first speckle interferogram and each second speckle interferogram, determine the first liveness identification result of the object to be identified according to the interference phase change diagram, and control the laser generator to generate structured light and send a second image acquisition command to the image acquisition unit 104 when the first liveness identification result indicates that the object to be identified is a live body.

[0168] Image acquisition unit 104 is used to acquire an image of the object to be identified in response to a second image acquisition command, obtain an image to be matched, and feed back the image to be matched to the controller 102;

[0169] The controller 102 is used to perform identity recognition processing based on the image to be matched, and obtain the identity recognition result of the object to be identified.

[0170] In one embodiment, such as Figure 1 As shown, the identification system also includes a first switch 116 and a second switch 118. The laser generating device includes a laser 106, a beam splitter 108, a speckle generation unit, and a structured light generation filter 110. The first switch 116 is disposed in the first output optical path of the beam splitter 108, and the second switch 118 is disposed in the second output optical path of the beam splitter 108, wherein:

[0171] The controller 102 is used to control the first switch 116 to open and the second switch 118 to close in response to an identification command, and to control the laser 106 to generate a target laser.

[0172] The beam splitter 108 is used to split the target laser into a first target laser and a second target laser.

[0173] The first switch 116 is used to allow the first target laser to be incident on the speckle generation unit when the first switch 116 is turned on.

[0174] The second switch 118 is used to prevent the second target laser from being incident on the structured light generating filter 110 when the second switch 118 is closed.

[0175] The speckle generation unit is used to expand the first target laser beam to obtain the expanded first target laser beam, and to split the expanded first target laser beam to obtain the first correlated light and the second correlated light, wherein the expanded first target laser beam is not reflected by the object to be identified.

[0176] In one embodiment, such as Figure 1 As shown, the identification system includes:

[0177] The controller 102 is used to control the first switch 116 to close and the second switch 118 to open when the first liveness detection result indicates that the object to be identified is a live body, and to control the laser 106 to generate target laser.

[0178] The first switch 116 is used to prevent the first target laser from being incident on the speckle generation unit when the first switch 116 is closed;

[0179] The second switch 118 is used to allow the second target laser to be incident on the structured light generation filter 110 when the second switch 118 is turned on.

[0180] Structured light generating filter 110 is used to generate structured light based on the incident second target laser.

[0181] In one embodiment, such as Figure 2 As shown, the laser generating device includes a correlation light generator and a structured light generator 202, wherein:

[0182] Controller 102 is used to control the relevant light generator to generate expanded target laser in response to an identification command;

[0183] A correlation light generator is used to split the expanded target laser beam to obtain a first correlation light and a second correlation light, wherein the expanded first target laser beam is not reflected by the object to be identified;

[0184] The controller 102 is also used to control the structured light generator 202 to generate structured light when the first liveness detection result indicates that the object to be identified is a live body.

[0185] In one embodiment, each first speckle interferogram includes a first reference interferogram; each second speckle interferogram includes a second reference interferogram; the controller 102 is specifically configured to:

[0186] Based on each of the first speckle interferograms, determine the first interference phase diagram of the first reference interferogram;

[0187] Based on each second speckle interferogram, the second interference phase diagram of the second reference interferogram is determined; the incident light corresponding to the first reference interferogram is the same as the incident light corresponding to the second reference interferogram; the incident light is light that has not been reflected by the object to be identified and is incident on the image acquisition unit 104;

[0188] Based on the first and second interference phase diagrams, determine the interference phase change diagram of the object to be identified from the first target time to the second target time.

[0189] In one embodiment, controller 102 is specifically used for:

[0190] Obtain at least one interference center in the interference phase change diagram;

[0191] Based on the position information of the interference center, the interference phase change map is divided into partitions to obtain a partitioned interference phase change map. The partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains an interference center.

[0192] Based on the interferometric phase change diagram after partitioning, the first liveness detection result of the object to be identified is determined.

[0193] In one embodiment, controller 102 is specifically used for:

[0194] Obtain the number of interference centers and their relative positions in the interference phase change diagram;

[0195] By comparing the number of interference circle centers in the interference phase change diagram with the preset number, the number comparison result is obtained;

[0196] If the number of interference centers is the same as the preset number, the relative positions of the interference centers are compared with the preset relative positions to obtain the position comparison results.

[0197] Based on the location comparison results, the first liveness detection result of the object to be identified is determined.

[0198] In one embodiment, controller 102 is specifically used for:

[0199] Based on the relative positions of the interference circle centers contained within the interference phase change region, the feature category corresponding to each interference phase change region is determined;

[0200] For any interference phase change region, the range of phase change corresponding to the interference phase change region is determined according to the characteristic category corresponding to the interference phase change region;

[0201] For any interference phase change region, obtain the actual phase change amount corresponding to the interference phase change region, and determine whether the actual phase change amount belongs to the range of phase change amount, and obtain the judgment result corresponding to the interference phase change region.

[0202] Based on the judgment results corresponding to at least one interference phase change region, the first liveness detection result of the object to be identified is determined.

[0203] In one embodiment, controller 102 is specifically used for:

[0204] Obtain the number of interference centers and their relative positions in the interference phase change diagram;

[0205] If the number of interference centers in the interference phase change diagram is the same as the preset number, and the relative positions of the interference centers in the interference phase change diagram are the same as the preset relative positions, the feature category corresponding to each interference phase change region is determined according to the relative positions of the interference centers contained in each interference phase change region.

[0206] In one embodiment, the controller 102 is further configured to:

[0207] If the first liveness detection result indicates that the object to be identified is not a live object, an action guidance prompt message is issued, and an action image of the object to be identified is captured;

[0208] The second liveness detection result is determined based on the motion image and the preset motion feature data corresponding to the preset specified motion contained in the motion guidance prompt message;

[0209] If the second liveness detection result indicates successful identification, an image of the object to be identified is acquired to obtain a matching image, and identity recognition processing is performed based on the matching image to obtain the identity recognition result of the object to be identified.

[0210] Based on the same inventive concept, this application also provides an identification device for implementing the identification method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more identification device embodiments provided below can be found in the limitations of the identification method described above, and will not be repeated here.

[0211] In one embodiment, such as Figure 9 As shown, an identification device is provided, comprising:

[0212] The first acquisition module 902 is used to acquire a preset number of first speckle interferograms of the object to be identified at the first target time, with a preset phase difference between two adjacent first speckle interferograms.

[0213] The first acquisition module 904 is used to acquire a preset number of second speckle interferograms of the object to be identified at the second target time, with a preset phase difference between two adjacent second speckle interferograms.

[0214] The determination module 906 is used to determine the interference phase change pattern of the object to be identified from the first target time to the second target time based on each first speckle interferogram and each second speckle interferogram;

[0215] The first liveness detection module 908 is used to determine the first liveness detection result of the object to be identified based on the interference phase change diagram;

[0216] The identity recognition module 910 is used to acquire an image of the object to be recognized when the first liveness recognition result indicates that the object to be recognized is a live object, to obtain a matching image, and to perform identity recognition processing based on the matching image to obtain the identity recognition result of the object to be recognized.

[0217] In one embodiment, each first speckle interferogram includes a first reference interferogram; each second speckle interferogram includes a second reference interferogram; the determining module 906 is specifically used for:

[0218] Based on each of the first speckle interferograms, determine the first interference phase diagram of the first reference interferogram;

[0219] Based on each second speckle interferogram, the second interference phase diagram of the second reference interferogram is determined; the incident light corresponding to the first reference interferogram is the same as the incident light corresponding to the second reference interferogram; the incident light is light that has not been reflected by the object to be identified and is incident on the image acquisition unit 104;

[0220] Based on the first and second interference phase diagrams, determine the interference phase change diagram of the object to be identified from the first target time to the second target time.

[0221] In one embodiment, the first liveness detection module 908 is specifically used for:

[0222] Obtain at least one interference center in the interference phase change diagram;

[0223] Based on the position information of the interference center, the interference phase change map is divided into partitions to obtain a partitioned interference phase change map. The partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains an interference center.

[0224] Based on the interferometric phase change diagram after partitioning, the first liveness detection result of the object to be identified is determined.

[0225] In one embodiment, the first liveness detection module 908 is specifically used for:

[0226] Obtain the number of interference centers and their relative positions in the interference phase change diagram;

[0227] By comparing the number of interference circle centers in the interference phase change diagram with the preset number, the number comparison result is obtained;

[0228] If the number of interference centers is the same as the preset number, the relative positions of the interference centers are compared with the preset relative positions to obtain the position comparison results.

[0229] Based on the location comparison results, the first liveness detection result of the object to be identified is determined.

[0230] In one embodiment, the first liveness detection module 908 is specifically used for:

[0231] Based on the relative positions of the interference circle centers contained within the interference phase change region, the feature category corresponding to each interference phase change region is determined;

[0232] For any interference phase change region, the range of phase change corresponding to the interference phase change region is determined according to the characteristic category corresponding to the interference phase change region;

[0233] For any interference phase change region, obtain the actual phase change amount corresponding to the interference phase change region, and determine whether the actual phase change amount belongs to the range of phase change amount, and obtain the judgment result corresponding to the interference phase change region.

[0234] Based on the judgment results corresponding to at least one interference phase change region, the first liveness detection result of the object to be identified is determined.

[0235] In one embodiment, the first liveness detection module 908 is specifically used for:

[0236] Obtain the number of interference centers and their relative positions in the interference phase change diagram;

[0237] If the number of interference centers in the interference phase change diagram is the same as the preset number, and the relative positions of the interference centers in the interference phase change diagram are the same as the preset relative positions, the feature category corresponding to each interference phase change region is determined according to the relative positions of the interference centers contained in each interference phase change region.

[0238] In one embodiment, the identification device further includes:

[0239] The third acquisition module is used to issue an action guidance prompt message and acquire the action image of the object to be identified when the first liveness recognition result indicates that the object to be identified is not a live body.

[0240] The second liveness detection module is used to determine the second liveness detection result based on the action image and the preset action feature data corresponding to the preset specified action contained in the action guidance prompt message.

[0241] The identity recognition module 910 is used to acquire an image of the object to be recognized when the second liveness recognition result indicates that the recognition is successful, obtain an image to be matched, and perform identity recognition processing based on the image to be matched to obtain the identity recognition result of the object to be recognized.

[0242] Each module in the aforementioned identification device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0243] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 10As shown, the computer device includes a processor, memory, input / output interfaces, a communication interface, a display unit, and an input device. The processor, memory, and input / output interfaces are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interfaces are used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements an identification method. The display unit is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0244] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0245] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0246] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0247] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0248] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0249] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0250] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0251] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A recognition method, characterized in that, The method includes: At the first target time, a preset number of first speckle interferograms of the object to be identified are acquired, and the two adjacent first speckle interferograms are separated by a preset phase. At the second target time, the preset number of second speckle interferograms of the object to be identified are acquired, and the preset phase difference is between two adjacent second speckle interferograms; Based on each of the first speckle interferograms and each of the second speckle interferograms, determine the interference phase change pattern of the object to be identified from the first target time to the second target time; Based on the interference phase change diagram, the first liveness detection result of the object to be identified is determined; If the first liveness detection result indicates that the object to be identified is a live body, an image of the object to be identified is acquired to obtain a matching image, and an identity recognition process is performed based on the matching image to obtain the identity recognition result of the object to be identified. The step of determining the first liveness detection result of the object to be identified based on the interference phase change diagram includes: Obtain at least one interference circle center in the interference phase change diagram; Based on the position information of the interference center, the interference phase change map is partitioned to obtain a partitioned interference phase change map, wherein the partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains one interference center; Based on the interference phase change diagram after partitioning, the first liveness detection result of the object to be identified is determined.

2. The method according to claim 1, characterized in that, Each of the first speckle interferograms includes a first reference interferogram; each of the second speckle interferograms includes a second reference interferogram; determining the interference phase change pattern of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms includes: Based on each of the first speckle interferograms, determine the first interference phase diagram of the first reference interferogram; Based on each of the second speckle interferograms, a second interference phase diagram of the second reference interferogram is determined; the incident light corresponding to the first reference interferogram is the same as the incident light corresponding to the second reference interferogram; the incident light is light that has not been reflected by the object to be identified and is incident on the image acquisition device; Based on the first interference phase diagram and the second interference phase diagram, the interference phase change diagram of the object to be identified from the first target time to the second target time is determined.

3. The method according to claim 1, characterized in that, The step of determining the first liveness detection result of the object to be identified based on the interference phase change map after partitioning includes: Obtain the number of interference circle centers and the relative positions of the interference circle centers in the interference phase change diagram; By comparing the number of interference circle centers in the interference phase change diagram with a preset number, the number comparison result is obtained; If the number comparison result indicates that the number of interference centers is the same as the preset number, the relative position of the interference centers is compared with the preset relative position to obtain the position comparison result; Based on the location comparison results, the first liveness detection result of the object to be identified is determined.

4. The method according to claim 1, characterized in that, The step of determining the first liveness detection result of the object to be identified based on the interference phase change map after partitioning includes: Based on the relative positions of the interference circle centers contained within the interference phase change region, the feature category corresponding to each interference phase change region is determined; For any of the interference phase change regions, the range of phase change corresponding to the interference phase change region is determined according to the feature category corresponding to the interference phase change region; For any of the aforementioned interference phase change regions, the actual phase change amount corresponding to the interference phase change region is obtained, and it is determined whether the actual phase change amount belongs to the range of the phase change amount, thereby obtaining the determination result corresponding to the interference phase change region. Based on the judgment result corresponding to at least one of the interference phase change regions, the first liveness detection result of the object to be identified is determined.

5. The method according to claim 4, characterized in that, The step of determining the feature category corresponding to each interference phase change region based on the relative position of the interference circle centers contained within the interference phase change region includes: Obtain the number of interference circle centers and the relative positions of the interference circle centers in the interference phase change diagram; When the number of interference circle centers in the interference phase change diagram is the same as the preset number, and the relative positions of the interference circle centers in the interference phase change diagram are the same as the preset relative positions, the feature category corresponding to each interference phase change region is determined according to the relative positions of the interference circle centers contained in each interference phase change region.

6. The method according to claim 1, characterized in that, The method further includes: If the first liveness detection result indicates that the object to be identified is not a live object, an action guidance prompt message is issued, and an action image of the object to be identified is captured; The second liveness detection result is determined based on the motion image and the preset motion feature data corresponding to the preset specified motion contained in the motion guidance prompt message; If the second liveness detection result indicates successful identification, an image of the object to be identified is acquired to obtain a matching image, and identity recognition processing is performed based on the matching image to obtain the identity recognition result of the object to be identified.

7. An identification system, characterized in that, The system includes a controller, an image acquisition unit, and a laser generator, wherein: The controller is configured to respond to an identification command, control the laser generator to generate coherent light, and send a first image acquisition command to the image acquisition device. The first image acquisition command is configured to instruct the image acquisition device to acquire images at a first target time and a second target time. The image acquisition device is configured to, in response to the first image acquisition command, acquire a preset number of first speckle interferograms of the object to be identified at the first target time, and acquire the preset number of second speckle interferograms of the object to be identified at the second target time, and feed back the first speckle interferograms and the second speckle interferograms to the controller; there is a preset phase difference between two adjacent first speckle interferograms; there is a preset phase difference between two adjacent second speckle interferograms. The controller is configured to determine the interference phase change map of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms, determine the first liveness detection result of the object to be identified based on the interference phase change map, and control the laser generator to generate structured light and send a second image acquisition command to the image acquisition device when the first liveness detection result indicates that the object to be identified is a live body. The image acquisition device is used to acquire an image of the object to be identified in response to the second image acquisition command, obtain an image to be matched, and feed back the image to be matched to the controller; The controller is used to perform identity recognition processing based on the image to be matched, and obtain the identity recognition result of the object to be identified. The controller is specifically configured to acquire at least one interference center in the interference phase change map; partition the interference phase change map according to the position information of the interference center to obtain a partitioned interference phase change map, wherein the partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains one interference center; and determine the first liveness detection result of the object to be identified according to the partitioned interference phase change map.

8. The system according to claim 7, characterized in that, The system further includes a first switch and a second switch. The laser generating device includes a laser, a beam splitter, a speckle generation unit, and a structured light generation filter. The first switch is disposed in the first output optical path of the beam splitter, and the second switch is disposed in the second output optical path of the beam splitter, wherein: The controller is configured to respond to the identity recognition command by controlling the first switch to open and the second switch to close, and to control the laser to generate target laser. The beam splitter is used to split the target laser into a first target laser and a second target laser; The first switch is used to allow the first target laser to be incident on the speckle generation unit when the first switch is turned on; The second switch is used to prevent the second target laser from being incident on the structured light generating filter when the second switch is closed; The speckle generation unit is used to expand the first target laser beam to obtain an expanded first target laser beam, and to split the expanded first target laser beam to obtain a first correlated light and a second correlated light, wherein the expanded first target laser beam is not reflected by the object to be identified.

9. The system according to claim 8, characterized in that, The system includes: The controller is configured to, when the first liveness detection result indicates that the object to be identified is a live body, control the first switch to close and the second switch to open, and control the laser to generate target laser; The first switch is used to prevent the first target laser from being incident on the speckle generation unit when the first switch is closed; The second switch is used to allow the second target laser to be incident on the structured light generating filter when the second switch is turned on; The structured light generating filter is used to generate the structured light based on the incident second target laser.

10. The system according to claim 7, characterized in that, The laser generating device includes a correlation light generator and a structured light generator, wherein: The controller is used to control the relevant light generator to generate expanded target laser in response to an identification command; The correlation light generator is used to split the expanded target laser beam to obtain a first correlation light and a second correlation light, wherein the expanded first target laser beam is not reflected by the object to be identified; The controller is further configured to control the structured light generator to generate the structured light when the first liveness detection result indicates that the object to be identified is a live body.

11. An identification device, characterized in that, The device includes: The first acquisition module is used to acquire a preset number of first speckle interferograms of the object to be identified at the first target time, wherein the two adjacent first speckle interferograms are separated by a preset phase. The second acquisition module is used to acquire the preset number of second speckle interferograms of the object to be identified at the second target time, wherein the preset phase difference exists between two adjacent second speckle interferograms. The determining module is used to determine the interference phase change pattern of the object to be identified from the first target time to the second target time based on each of the first speckle interferograms and each of the second speckle interferograms; The liveness detection module is used to determine the first liveness detection result of the object to be identified based on the interference phase change diagram. The identity recognition module is used to acquire an image of the object to be identified when the first liveness recognition result indicates that the object to be identified is a live object, to obtain a matching image, and to perform identity recognition processing based on the matching image to obtain the identity recognition result of the object to be identified. The liveness detection module is specifically used to acquire at least one interference center in the interference phase change map; to partition the interference phase change map according to the position information of the interference center to obtain a partitioned interference phase change map, wherein the partitioned interference phase change map includes at least one interference phase change region, and each interference phase change region contains one interference center; and to determine the first liveness detection result of the object to be identified according to the partitioned interference phase change map.

12. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

14. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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