Living body detection method and device, electronic equipment and storage medium

Abstract

The invention relates to a living body detection method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a pulse wave signal of a to-be-detected object; performing frequency spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum in a preset frequency band; acquiring a fundamental wave frequency of the pulse wave signal; determining a plurality of harmonic frequencies in a preset frequency band according to the fundamental wave frequency; and determining whether the to-be-detected object is a living body or not according to the amplitude corresponding to the fundamental wave frequency, the amplitudes corresponding to the plurality of harmonic frequencies and the amplitude corresponding to each frequency in the frequency domain amplitude spectrum. According to the method, frequency spectrum transformation is carried out on the pulse wave signal, whether the to-be-detected object is a living body or not can be identified according to the relation between the amplitude corresponding to the fundamental wave frequency, the amplitude corresponding to the harmonic frequency and the amplitude corresponding to each frequency in the frequency domain amplitude spectrum, only the pulse wave signal needs to be processed, and the living body detection efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a living body detection method, device, electronic device and storage medium. Background Art

[0002] Photoplethysmograph (PPG) signal is a commonly used signal for measuring vital signs and can be measured with the help of a pulse wave sensor.

[0003] Due to the limitation of the pulse wave sensor measurement principle, in actual applications, some non-living objects, such as tissues or clothing, trigger the pulse wave sensor measurement and obtain false pulse wave signals. In this case, if the PPG signal generated by the non-living object is used to calculate the vital signs, a large number of invalid results may be generated, or even an alarm may be triggered by mistake.

[0004] In the related art, it is necessary to use signals other than PPG, such as electrocardiogram signals, acceleration, temperature, etc., to identify whether the object generating the pulse wave signal is a living body. The identification process is complicated and time-consuming. Summary of the invention

[0005] Based on this, the purpose of the present application is to provide a liveness detection method, device, electronic device and storage medium, which can improve the efficiency of liveness detection.

[0006] According to a first aspect of an embodiment of the present application, a living body detection method is provided, comprising the following steps:

[0007] Acquiring a pulse wave signal of a subject to be detected;

[0008] Performing spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band;

[0009] Obtaining the fundamental frequency of the pulse wave signal;

[0010] According to the fundamental frequency, a plurality of harmonic frequencies within a preset frequency band are determined;

[0011] Whether the object to be detected is a living body is determined based on the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum.

[0012] According to a second aspect of an embodiment of the present application, a living body detection device is provided, including:

[0013] A signal acquisition module, used to acquire a pulse wave signal of a subject to be detected;

[0014] An amplitude spectrum acquisition module is used to perform spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band;

[0015] A fundamental frequency acquisition module is used to acquire the fundamental frequency of the pulse wave signal;

[0016] A harmonic frequency determination module, used to determine a number of harmonic frequencies within a preset frequency band according to the fundamental frequency;

[0017] The living body detection module is used to determine whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum.

[0018] According to a third aspect of an embodiment of the present application, there is provided an electronic device, comprising: a processor and a memory; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the processor and executing any one of the above-mentioned liveness detection methods.

[0019] According to a fourth aspect of an embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the liveness detection method as described above is implemented.

[0020] The embodiment of the present application obtains the pulse wave signal of the object to be detected; performs spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band; obtains the fundamental frequency of the pulse wave signal; determines several harmonic frequencies within the preset frequency band according to the fundamental frequency; determines whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum. The present application performs spectrum transformation on the pulse wave signal, and can identify whether the object to be detected is a living body according to the relationship between the amplitude corresponding to the fundamental frequency, the amplitude corresponding to the harmonic frequency, and the amplitude corresponding to each frequency in the frequency domain amplitude spectrum. It only needs to process the pulse wave signal, thereby improving the efficiency of liveness detection.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

[0022] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a liveness detection method provided in one embodiment of the present application;

[0024] Figure 2 A schematic diagram of the process of step S30 in the living body detection method provided in one embodiment of the present application;

[0025] Figure 3 A schematic diagram of the process of step S40 in the living body detection method provided in one embodiment of the present application;

[0026] Figure 4 A schematic diagram of the process of step S50 in the living body detection method provided in one embodiment of the present application;

[0027] Figure 5 A schematic diagram of the flow of step S54 in the living body detection method provided in one embodiment of the present application;

[0028] Figure 6 A structural block diagram of a living body detection device provided in one embodiment of the present application;

[0029] Figure 7 A schematic block diagram of the structure of an electronic device provided for one embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0031] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0032] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0033] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0034] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0035] In order to better understand the design scheme of the present application, it is explained below in conjunction with specific application scenarios.

[0036] The application scenario of the liveness detection method of the embodiment of the present application includes a pulse wave sensor and a liveness detection device; the pulse wave sensor is connected to the liveness detection device, and the pulse wave sensor transmits the pulse wave signal of the detected object to be detected to the liveness detection device.

[0037] The liveness detection method of the embodiment of the present application can be performed by a liveness detection device, which can be implemented by software and / or hardware. The liveness detection device can be composed of two or more physical entities, or it can be composed of one physical entity. The hardware pointed to by the liveness detection device essentially refers to computer equipment. For example, the liveness detection device can be a computer, a mobile phone, a tablet or an intelligent interactive tablet or other intelligent device.

[0038] In order to better understand the design of the present application, the following first introduces the liveness detection method of the related art.

[0039] When performing liveness detection, a pulse wave sensor is usually used to collect PPG signals for detection. However, for non-living objects, such as tissues or clothing, the pulse wave sensor can also trigger measurement, obtaining false pulse wave signals. At this time, if the PPG signals generated by non-living objects are used to calculate vital signs, a large number of invalid results may be generated, or even an alarm may be triggered by mistake.

[0040] In the related art, in order to improve the accuracy of liveness detection, it is necessary to use signals other than PPG to identify whether the object generating the pulse wave signal is alive. For example, in many wearable devices, a pulse wave sensor, a heart rate detection module and a temperature detection module are installed. The pulse wave signal of the object is detected by the pulse wave sensor, the heart rate signal of the object is detected by the heart rate detection module, and the body temperature signal of the object is detected by the temperature detection module. By comprehensively analyzing the pulse wave signal, the heart rate signal and the body temperature signal, it is determined whether the object generating the pulse wave signal is alive. The identification process is complicated and time-consuming.

[0041] To this end, an embodiment of the present application proposes a liveness detection method.

[0042] See also Figure 1 , Figure 1A flow chart of a liveness detection method provided in one embodiment of the present application, the method includes the following steps:

[0043] S10: Acquire the pulse wave signal of the object to be detected.

[0044] The object to be tested is the object that needs to be judged as alive, and the object to be tested may be alive or non-living. A living object refers to an organism with vital signs, such as humans and animals, and a non-living object refers to an object without life characteristics, such as tissues, clothes and other debris.

[0045] In the embodiment of the present application, the pulse wave sensor detects the pulse wave signal of the object to be detected, collects the pulse wave signal detected by the pulse wave sensor within a period of time, and then transmits the pulse wave signal to the living body detection device. For example, the pulse wave signal of 8 seconds in duration.

[0046] S20: Performing spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band.

[0047] The spectrum transform is used to transform the time domain signal into the corresponding frequency domain signal. Specifically, the spectrum transform includes but is not limited to chirp z-transform (CZT transform), fast Fourier transform and discrete Fourier transform.

[0048] The preset frequency band is a preset frequency range. Specifically, since a common pulse rate of a person is between 30 and 300 bpm, the corresponding converted preset frequency band is 0.5 to 5 Hz.

[0049] In an embodiment of the present application, the liveness detection device can obtain a frequency domain amplitude spectrum by performing spectrum transformation on the pulse wave signal. The frequency domain amplitude spectrum characterizes the distribution of the amplitude of the signal with frequency, including different frequencies and the amplitude corresponding to each frequency. According to the preset frequency band, the frequency domain amplitude spectrum is screened to obtain the frequency domain amplitude spectrum within the preset frequency band. Specifically, it is determined whether each frequency in the frequency domain amplitude spectrum is within the preset frequency band, a number of frequencies within the preset frequency band are determined, the amplitudes corresponding to the several frequencies are obtained, and the frequency domain amplitude spectrum within the preset frequency band is obtained according to the several frequencies within the preset frequency band and the corresponding amplitudes.

[0050] S30: Acquire the fundamental frequency of the pulse wave signal.

[0051] Among them, the fundamental wave refers to the sinusoidal wave component in a complex periodic oscillation that is equal to the longest period of the oscillation, and the frequency corresponding to this period is called the fundamental wave frequency.

[0052] In the embodiment of the present application, after the liveness detection device performs spectrum transformation on the pulse wave signal, the fundamental frequency can be obtained from the frequency domain amplitude spectrum. The pulse rate can also be determined from the pulse wave signal, and the fundamental frequency can be obtained according to the pulse rate. The pulse rate refers to the number of pulse beats per minute.

[0053] S40: Determine a plurality of harmonic frequencies within a preset frequency band according to the fundamental frequency.

[0054] Among them, harmonics refer to sinusoidal wave components whose frequencies are equal to integer multiples of the fundamental frequency, and the harmonic frequencies are integer multiples of the fundamental frequency.

[0055] In the embodiment of the present application, after obtaining the fundamental frequency, the liveness detection device may multiply the fundamental frequency by several integers to obtain several harmonic frequencies. According to a preset frequency band, all harmonic frequencies are screened to obtain several harmonic frequencies within the preset frequency band.

[0056] S50: Determine whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to the plurality of harmonic frequencies, and the amplitudes corresponding to the respective frequencies in the frequency domain amplitude spectrum.

[0057] For the pulse wave signal generated by a living body, since the living body has a pulse, a periodic pulse wave signal will be generated. In the frequency domain amplitude spectrum, it is manifested as a frequency component with a higher amplitude, and there will be multiple harmonics. For the pulse wave signal generated by a non-living body, since the non-living body does not have a pulse, the amplitudes corresponding to the fundamental wave and harmonic waves in the frequency domain amplitude spectrum are smaller.

[0058] In an embodiment of the present application, the living body detection device calculates a first ratio of the amplitude corresponding to the fundamental frequency to the sum of the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum, calculates a second ratio of the sum of the amplitudes corresponding to several harmonic frequencies to the sum of the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum, and determines whether the object to be detected is a living body based on the first ratio and the second ratio.

[0059] In an optional embodiment, if the first ratio is greater than or equal to a first preset threshold, and the second ratio is greater than or equal to a second preset threshold, the liveness detection device determines that the object to be detected is a live body; if the first ratio is less than the first preset threshold, or the second ratio is less than the second preset threshold, the object to be detected is determined to be a non-live body. In another optional embodiment, the liveness detection device calculates the sum of the first ratio and the second ratio, and if the sum is greater than or equal to the preset threshold, the object to be detected is determined to be a live body, and if the sum is less than the preset threshold, the object to be detected is determined to be a non-live body.

[0060] By applying the embodiment of the present application, the pulse wave signal of the object to be detected is obtained; the pulse wave signal is spectrally transformed to obtain a frequency domain amplitude spectrum within a preset frequency band; the fundamental frequency of the pulse wave signal is obtained; according to the fundamental frequency, several harmonic frequencies within the preset frequency band are determined; according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum, it is determined whether the object to be detected is a living body. The present application performs a spectrum transformation on the pulse wave signal, and according to the relationship between the amplitude corresponding to the fundamental frequency, the amplitude corresponding to the harmonic frequency, and the amplitude corresponding to each frequency in the frequency domain amplitude spectrum, it can identify whether the object to be detected is a living body. It only needs to process the pulse wave signal, and there is no need to use other life characteristic signals for liveness detection, thereby improving the efficiency of liveness detection.

[0061] In an optional embodiment, before step S20, step S21 is included, which is specifically as follows:

[0062] S21: performing a preprocessing operation on the pulse wave signal to obtain a preprocessed pulse wave signal; wherein the preprocessing operation includes but is not limited to filtering and denoising.

[0063] Among them, filtering is used to obtain the pulse wave signal within a certain frequency band, and filtering includes low-pass filtering, high-pass filtering and band-pass filtering. De-noising is used to remove high-frequency noise in the pulse wave signal.

[0064] In an embodiment of the present application, a bandpass filter is used to perform bandpass filtering on the pulse wave signal to obtain a pulse wave signal within a certain frequency band. For example, the certain frequency band is 0.3 to 30 Hz. A denoising algorithm is used to denoise the pulse wave signal to obtain a denoised pulse wave signal. Among them, the denoising algorithm includes wavelet transform denoising, adaptive filtering denoising and spectral subtraction denoising.

[0065] By preprocessing the pulse wave signal, the quality of the pulse wave signal is improved.

[0066] In an alternative embodiment, see Figure 2 Step S30 includes steps S31 to S32, which are specifically as follows:

[0067] S31: Obtain the pulse rate of the pulse wave signal.

[0068] In the embodiment of the present application, the extreme value method is used to detect the peaks and troughs of the pulse wave signal to obtain the period of the pulse wave signal, and the inverse of the period is the pulse rate.

[0069] S32: Divide the pulse rate by a preset value to obtain the fundamental frequency of the pulse wave signal.

[0070] The preset value is 60. The pulse rate is the number of pulse beats per minute. The fundamental frequency is related to the pulse rate. For a living body, the fundamental frequency of the pulse wave signal is equivalent to the number of pulse beats per second. The fundamental frequency of the pulse wave signal can be obtained by dividing the pulse rate by 60.

[0071] The embodiment of the present application can automatically and quickly obtain the fundamental frequency of the pulse wave signal through the pulse rate of the pulse wave signal.

[0072] In an optional embodiment, step S30 includes step S301, which is specifically as follows:

[0073] S301: The frequency corresponding to the maximum amplitude in the frequency domain amplitude spectrum is taken as the fundamental frequency of the pulse wave signal.

[0074] In the embodiment of the present application, each frequency in the frequency domain amplitude spectrum corresponds to an amplitude, the amplitude corresponding to each frequency is obtained, the amplitudes corresponding to each frequency are compared, the maximum amplitude and the frequency corresponding to the maximum amplitude are determined, and the frequency corresponding to the maximum amplitude is used as the fundamental frequency of the pulse wave signal.

[0075] By comparing the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum, the fundamental frequency of the pulse wave signal can be automatically and quickly obtained.

[0076] In an alternative embodiment, see Figure 3 , step S40, including steps S401 to S402, are as follows:

[0077] S401: Calculate the frequency of the nth harmonic according to the fundamental frequency; wherein n is an integer greater than or equal to 2.

[0078] Among them, the frequency of the harmonic is equal to an integer multiple of the frequency of the fundamental wave. The wave with a frequency of 3 times the fundamental wave is called the third harmonic, the wave with a frequency of 5 times the fundamental wave is called the fifth harmonic, and so on.

[0079] In the embodiment of the present application, the fundamental frequency is multiplied by the harmonic order n to obtain the frequency of the nth harmonic.

[0080] S402: Determine a plurality of harmonic frequencies within a preset frequency band from the frequencies of the nth harmonics.

[0081] In the embodiment of the present application, after calculating the frequency of the nth harmonic, the frequency of each harmonic is compared with the preset frequency band to determine a number of harmonic frequencies within the preset frequency band. For example, the fundamental frequency is 1 Hz, the harmonic frequencies are 2 Hz, 3 Hz, 4 Hz, 5 Hz, 6 Hz, ..., and the preset frequency band is 0.5 to 5 Hz, then the harmonic frequencies of 2 Hz, 3 Hz, 4 Hz, and 5 Hz are within the preset frequency band.

[0082] By screening the harmonic frequencies according to the preset frequency band, several harmonic frequencies within the preset frequency band can be automatically and quickly obtained.

[0083] In an alternative embodiment, see Figure 4 , step S50, including steps S51 to S54, are as follows:

[0084] S51: summing the amplitude corresponding to the fundamental frequency and the amplitudes corresponding to all harmonic frequencies to obtain a first summation result;

[0085] S52: summing the amplitudes corresponding to the frequencies in the frequency domain amplitude spectrum to obtain a second summation result;

[0086] S53: Calculate the ratio of the first summation result to the second summation result;

[0087] S54: Compare the ratio with a preset threshold to determine whether the object to be detected is a living body.

[0088] In the embodiment of the present application, the specific expression of the ratio is:

[0089]

[0090] Where f1 represents the fundamental frequency, f m represents each harmonic frequency, where m ≥ 2 and is an integer, and a[f m ] represents the amplitude corresponding to the fundamental frequency and the amplitude corresponding to each harmonic frequency. represents the first summation result, w represents each frequency in the frequency domain amplitude spectrum, a[w] represents the amplitude corresponding to each frequency in the frequency domain amplitude spectrum, represents the second summation result, and r represents the ratio.

[0091] After the ratio is obtained, the ratio is compared with a preset threshold to obtain a comparison result. According to the comparison result, it can be determined whether the object to be detected is a living body.

[0092] Whether the object to be detected is alive can be automatically and quickly determined by the sum of the amplitude corresponding to the fundamental frequency and the amplitude corresponding to the harmonic frequency, and the sum of the amplitude corresponding to each frequency in the frequency domain amplitude spectrum.

[0093] In an alternative embodiment, see Figure 5 Step S54 includes steps S541 to S542, which are specifically as follows:

[0094] S541: If the ratio is greater than or equal to a preset threshold, determining that the object to be detected is a living body;

[0095] S542: If the ratio is less than a preset threshold, it is determined that the object to be detected is a non-living body.

[0096] The preset threshold may be a value obtained after analyzing multiple experimental data of liveness detection and non-liveness detection, and is used to distinguish liveness from non-liveness.

[0097] In the embodiment of the present application, by comparing the ratio with a preset threshold, it is possible to automatically and quickly determine whether the object to be detected is a living body.

[0098] The present application also provides a device embodiment, which can be used to execute the content of the liveness detection method in the embodiment of the present application. For details not disclosed in the device embodiment of the present application, please refer to the content of the liveness detection method in the embodiment of the present application.

[0099] See also Figure 6 , which shows a schematic diagram of the structure of a liveness detection device provided by an embodiment of the present application. The liveness detection device 6 provided by the embodiment of the present application includes:

[0100] A signal acquisition module 61 is used to acquire a pulse wave signal of a subject to be detected;

[0101] The amplitude spectrum acquisition module 62 is used to perform spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band;

[0102] A fundamental frequency acquisition module 63 is used to acquire the fundamental frequency of the pulse wave signal;

[0103] The harmonic frequency determination module 64 is used to determine a plurality of harmonic frequencies within a preset frequency band according to the fundamental frequency;

[0104] The living body detection module 65 is used to determine whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum.

[0105] Optional, fundamental frequency acquisition module, including:

[0106] A pulse rate acquisition unit, used for acquiring the pulse rate of the pulse wave signal;

[0107] The fundamental frequency acquisition unit is used to divide the pulse rate by a preset value to obtain the fundamental frequency of the pulse wave signal.

[0108] Optional, fundamental frequency acquisition module, including:

[0109] The fundamental frequency determination unit is used to take the frequency corresponding to the maximum amplitude in the frequency domain amplitude spectrum as the fundamental frequency of the pulse wave signal.

[0110] Optional, harmonic frequency determination module, including:

[0111] A frequency calculation unit, used to calculate the frequency of the nth harmonic according to the fundamental frequency; wherein n is an integer greater than or equal to 2;

[0112] The harmonic frequency determination unit is used to determine a plurality of harmonic frequencies within a preset frequency band from the frequency of the nth harmonic.

[0113] Optional, liveness detection module, including:

[0114] A first summation result obtaining unit, used for summing the amplitude corresponding to the fundamental frequency and the amplitude corresponding to all harmonic frequencies to obtain a first summation result;

[0115] A second summation result obtaining unit, used for summing the amplitudes corresponding to the respective frequencies in the frequency domain amplitude spectrum to obtain a second summation result;

[0116] a ratio calculation unit, used to calculate the ratio of the first summation result to the second summation result;

[0117] The ratio comparison unit is used to compare the ratio with a preset threshold value to determine whether the object to be detected is a living body.

[0118] Optional, ratio comparison unit, including:

[0119] A first judgment unit, configured to determine that the object to be detected is a living body if the ratio is greater than or equal to a preset threshold;

[0120] The second judgment unit is used to determine that the object to be detected is a non-living body if the ratio is less than a preset threshold.

[0121] By applying the embodiment of the present application, the pulse wave signal of the object to be detected is obtained; the pulse wave signal is spectrally transformed to obtain a frequency domain amplitude spectrum within a preset frequency band; the fundamental frequency of the pulse wave signal is obtained; according to the fundamental frequency, several harmonic frequencies within the preset frequency band are determined; according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to several harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum, it is determined whether the object to be detected is a living body. The present application performs a spectral transformation on the pulse wave signal, and according to the relationship between the amplitude corresponding to the fundamental frequency, the amplitude corresponding to the harmonic frequency, and the amplitude corresponding to each frequency in the frequency domain amplitude spectrum, it can identify whether the object to be detected is a living body. Only the pulse wave signal needs to be processed, which improves the efficiency of liveness detection.

[0122] The present application also provides a device embodiment that can be used to execute the content of the liveness detection method in the embodiment of the present application. For details not disclosed in the device embodiment of the present application, please refer to the content of the liveness detection method in the embodiment of the present application.

[0123] See also Figure 7The present application also provides an electronic device 300, which may be a computer, a mobile phone, a tablet computer, a liveness detection device, etc. In an exemplary embodiment of the present application, the electronic device 300 is a liveness detection device, which includes: at least one processor 301, at least one memory 302, at least one display, at least one network interface 303, a user interface 304, and at least one communication bus 305.

[0124] The user interface 304 is mainly used to provide an input interface for the user and obtain data input by the user. Optionally, the user interface may also include a standard wired interface or a wireless interface.

[0125] The network interface 303 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

[0126] The communication bus 305 is used to realize the connection and communication between these components.

[0127] Among them, the processor 301 may include one or more processing cores. The processor uses various interfaces and lines to connect various parts of the entire electronic device, and executes various functions of the electronic device and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory. Optionally, the processor can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor can integrate one or more combinations of central processing unit (Central Processing Unit, CPU), image processor (Graphics Processing Unit, GPU) and modem. Among them, the CPU mainly processes the operating system, user interface and application program, etc.; the GPU is responsible for rendering and drawing the content to be displayed by the display layer; the modem is used to process wireless communication. It can be understood that the above-mentioned modem may not be integrated into the processor, but implemented by a single chip.

[0128] Among them, the memory 302 may include a random access memory (Random Access Memory, RAM) and may also include a read-only memory (Read-Only Memory). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory can be used to store instructions, programs, codes, code sets or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned method embodiments, etc.; the data storage area may store data involved in the above-mentioned method embodiments, etc. The memory may also be optionally at least one storage device located away from the aforementioned processor. As Figure 7 As shown, the memory as a computer storage medium may include an operating system, a network communication module, a user interface module, and an operating application program.

[0129] The processor can be used to call the application of the liveness detection method stored in the memory, and specifically execute the steps of the liveness detection method of the above-mentioned embodiment. The specific execution process can refer to the specific description shown in the liveness detection method of the embodiment, which will not be repeated here.

[0130] The present application also provides a computer-readable storage medium on which a computer program is stored, and the instructions are suitable for being loaded by a processor and executing the method steps of the above-mentioned embodiment 1. The specific execution process can refer to the specific description shown in the embodiment, and will not be repeated here. The device where the storage medium is located can be a personal computer, a laptop computer, a smart phone, a tablet computer and other electronic devices.

[0131] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can refer to the partial description of the method embodiments. The device embodiments described above are merely schematic, wherein the components described as separate parts may or may not be physically separated, and the parts displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0132] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0133] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the function selected in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 function selected in a box or multiple boxes.

[0134] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 steps for the function selected in a box or multiple boxes.

[0135] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0136] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0137] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0138] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0139] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for detecting a living body, characterized in that: The steps include: Acquiring a pulse wave signal of a subject to be detected; Performing spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band; Acquiring the fundamental frequency of the pulse wave signal; Determining, according to the fundamental frequency, a plurality of harmonic frequencies within the preset frequency band; Whether the object to be detected is a living body is determined according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to a plurality of the harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum.

2. The method for liveness detection according to claim 1, characterized in that: The step of obtaining the fundamental frequency of the pulse wave signal comprises: Acquiring the pulse rate of the pulse wave signal; The pulse rate is divided by a preset value to obtain the fundamental frequency of the pulse wave signal.

3. The method for liveness detection according to claim 1, characterized in that: The step of obtaining the fundamental frequency of the pulse wave signal comprises: The frequency corresponding to the maximum amplitude in the frequency domain amplitude spectrum is used as the fundamental frequency of the pulse wave signal.

4. The method for liveness detection according to claim 1, characterized in that: The step of determining whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to the plurality of harmonic frequencies, and the amplitudes corresponding to the respective frequencies in the frequency domain amplitude spectrum comprises: Summing the amplitude corresponding to the fundamental frequency and the amplitudes corresponding to all the harmonic frequencies to obtain a first summation result; Sum the amplitudes corresponding to the frequencies in the frequency domain amplitude spectrum to obtain a second summation result; Calculating a ratio of the first summation result to the second summation result; The ratio is compared with a preset threshold to determine whether the object to be detected is a living body.

5. The method for detecting living body according to claim 4, characterized in that: The step of comparing the ratio with a preset threshold to determine whether the object to be detected is a living body comprises: If the ratio is greater than or equal to a preset threshold, it is determined that the object to be detected is a living body; If the ratio is less than a preset threshold, it is determined that the object to be detected is a non-living object.

6. The method for detecting a living body according to any one of claims 1 to 5, characterized in that: The step of determining a plurality of harmonic frequencies within the preset frequency band according to the fundamental frequency comprises: Calculate the frequency of the nth harmonic according to the fundamental frequency; wherein n is an integer greater than or equal to 2; A plurality of harmonic frequencies within the preset frequency range are determined from the frequencies of the nth harmonics.

7. The method for detecting a living body according to any one of claims 1 to 5, characterized in that: Before the step of performing spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band, the method includes: A preprocessing operation is performed on the pulse wave signal to obtain a preprocessed pulse wave signal; wherein the preprocessing operation includes but is not limited to filtering and denoising.

8. A living body detection device, characterized in that: include: A signal acquisition module, used to acquire a pulse wave signal of a subject to be detected; An amplitude spectrum acquisition module, used for performing spectrum transformation on the pulse wave signal to obtain a frequency domain amplitude spectrum within a preset frequency band; A fundamental frequency acquisition module, used to acquire the fundamental frequency of the pulse wave signal; A harmonic frequency determination module, used to determine a plurality of harmonic frequencies within the preset frequency band according to the fundamental frequency; The living body detection module is used to determine whether the object to be detected is a living body according to the amplitude corresponding to the fundamental frequency, the amplitudes corresponding to a plurality of the harmonic frequencies, and the amplitudes corresponding to each frequency in the frequency domain amplitude spectrum.

9. An electronic device, characterized in that: include: A processor and a memory; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the processor and executing the liveness detection method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the living body detection method according to any one of claims 1 to 7 is implemented.

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