CN112183174A

CN112183174A - Fingerprint identification method and device, terminal equipment and storage medium

Info

Publication number: CN112183174A
Application number: CN201910606423.0A
Authority: CN
Inventors: 常冰; 衣强; 赵晓娜; 常新苗; 王思善
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2021-01-05

Abstract

The embodiment of the application provides a fingerprint identification method, a fingerprint identification device, terminal equipment and a storage medium, wherein the method comprises the following steps: the method comprises the steps of acquiring a first fingerprint image and a second fingerprint image which are acquired at different moments, determining a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image, and determining that the identification is successful when the first pressure value and the second pressure value meet different pressure levels and the first fingerprint image and the second fingerprint image are both acquired by acquiring real fingerprints. In the technical scheme, whether the acquired fingerprint image is acquired by acquiring the fake fingerprint can be detected without acquiring the fingerprint by using a high-definition optical fingerprint sensor, the cost is reduced, the problems of limitation of the existing size, power consumption and the like are solved, the fingerprint identification safety is improved, and the user experience is improved.

Description

Fingerprint identification method and device, terminal equipment and storage medium

Technical Field

The present application relates to the field of terminal technologies, and in particular, to a fingerprint identification method and apparatus, a terminal device, and a storage medium.

Background

With the rapid development of network technology, terminal devices with high screen occupation ratio become an inevitable trend of the development of the current intelligent terminals. At the present stage, the fingerprint identification function of the terminal equipment with high screen occupation ratio is generally realized by using an optical fingerprint sensor under the screen, and on the premise of improving the screen occupation ratio of the terminal equipment, the terminal equipment is ensured to have the fingerprint identification function.

In the prior art, because the false fingerprint film made of certain materials is very similar to the real fingerprint film of a user, the problem of false identification may exist, and therefore, whether the acquired fingerprint image comes from a real fingerprint or not can be judged by acquiring the high-definition fingerprint image and based on sweat pores and sweat information in the high-definition fingerprint image.

However, the high-definition fingerprint image needs to be acquired by using a high-definition optical fingerprint sensor, so that the cost is high, the occupied area is large, the power consumption is high, the method is not suitable for portable mobile terminals with limited volume, power consumption and the like, and potential safety hazards still exist.

Disclosure of Invention

The embodiment of the application provides a fingerprint identification method, a fingerprint identification device, terminal equipment and a storage medium, and aims to solve the problems of high cost, high power consumption and potential safety hazards existing in the conventional fingerprint identification anti-counterfeiting scheme.

The first aspect of the present application provides a fingerprint identification method, including:

acquiring a first fingerprint image and a second fingerprint image which are acquired at different moments;

determining a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image;

and when the first pressure value and the second pressure value meet different pressure levels and the first fingerprint image and the second fingerprint image are both obtained by acquiring a real fingerprint, determining that the identification is successful.

Optionally, the collection time interval between the first fingerprint image and the second fingerprint image satisfies a preset time interval threshold.

In a possible design of the first aspect, the acquiring the first fingerprint image and the second fingerprint image acquired at different time instants includes:

collecting multiple frames of fingerprint images when a user presses a fingerprint sensor once, wherein each frame of fingerprint image carries respective collection time and collection pressure value;

and acquiring the first fingerprint image and the second fingerprint image from the multi-frame fingerprint image based on the acquisition time and the acquisition pressure value carried by each frame of fingerprint image.

In another possible design of the first aspect, the acquiring the first fingerprint image and the second fingerprint image acquired at different time includes:

acquiring the first fingerprint image when a user presses a fingerprint sensor;

calculating a first pressure value corresponding to the first fingerprint image, and determining a pressure grade to which the first pressure value belongs;

issuing a press indication based on a pressure level to which the first pressure value belongs, the press indication being for instructing the user to press the fingerprint sensor with a pressure level different from the pressure level to which the first pressure value belongs;

acquiring the second fingerprint image when the user presses the fingerprint sensor based on the press indication.

In yet another possible design of the first aspect, the acquiring the first fingerprint image and the second fingerprint image acquired at different time instants includes:

collecting multiple frames of fingerprint images when a user presses a fingerprint sensor once, wherein each frame of fingerprint image carries respective collection time;

calculating a pressure value corresponding to each frame of fingerprint image;

and acquiring the first fingerprint image and the second fingerprint image of which the pressure values respectively belong to different pressure levels from the multi-frame fingerprint image based on the pressure value corresponding to each frame of fingerprint image.

In yet another possible design of the first aspect, for any one of the first fingerprint image and the second fingerprint image, determining a pressure value corresponding to the fingerprint image includes:

determining an effective calculated area of the fingerprint image;

and determining a pressure value corresponding to the fingerprint image according to a preset corresponding relation between the area and the pressure value.

Optionally, the determining an effective calculation area of the fingerprint image includes:

determining an imaging area coefficient of the fingerprint image;

determining the actual imaging area in the fingerprint image according to the gray value of each pixel in the fingerprint image and a preset gray threshold value;

and determining the effective calculation area of the fingerprint image according to the imaging area coefficient and the actual imaging area.

Optionally, the determining an imaging area coefficient of the fingerprint image includes:

counting the number of imaging pixels in the fingerprint image, wherein the imaging pixels refer to pixels with gray values not being white;

and determining an imaging area coefficient of the fingerprint image according to the number of imaging pixels in the fingerprint image and the number of theoretical pixels included in the fingerprint image.

Optionally, the determining an actual imaging area in the fingerprint image according to the gray value of each pixel in the fingerprint image and a preset gray threshold includes:

determining effective pixels in the fingerprint image, wherein the effective pixels are pixels with gray values smaller than a preset gray threshold;

and determining the actual imaging area in the fingerprint image according to the number of the effective pixels in the fingerprint image.

In yet another possible design of the first aspect, the pressure rating includes: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

Optionally, the method further includes:

determining the pressure grade of the first pressure value;

when the first pressure value belongs to a first pressure grade, judging whether the first fingerprint image is obtained by collecting a real fingerprint;

when the first fingerprint image is obtained by collecting a real fingerprint, judging whether the second pressure value belongs to a second pressure grade;

and when the second pressure value belongs to a second pressure level, judging whether the second fingerprint image is obtained by acquiring a real fingerprint.

Optionally, the method further includes:

determining the pressure grade of the first pressure value and the pressure grade of the second pressure value;

judging whether the first pressure value and the second pressure value belong to different pressure levels or not;

and when the first pressure value and the second pressure value belong to different pressure levels, judging whether the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint.

In yet another possible design of the first aspect, for any one of the first fingerprint image and the second fingerprint image, determining whether a fingerprint image is obtained by acquiring an authentic fingerprint includes:

inputting the fingerprint image into a fingerprint identification model, and judging whether the fingerprint image is obtained by acquiring a real fingerprint, wherein the fingerprint identification model is a pre-trained model for identifying whether the input fingerprint image is obtained by acquiring a real fingerprint.

A second aspect of the present application provides a fingerprint identification device, including: the device comprises an acquisition module, a processing module and a determination module;

the acquisition module is used for acquiring a first fingerprint image and a second fingerprint image which are acquired at different moments;

the processing module is used for determining a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image;

the determining module is configured to determine that the identification is successful when the first pressure value and the second pressure value meet different pressure levels and the first fingerprint image and the second fingerprint image are both obtained by acquiring a real fingerprint.

In a possible design of the second aspect, the obtaining module has a plurality of frames of fingerprint images used for collecting a single time when the user presses the fingerprint sensor, each frame of fingerprint image carries a respective collecting time and collecting pressure value, and the first fingerprint image and the second fingerprint image are obtained from the plurality of frames of fingerprint images based on the collecting time and collecting pressure value carried by each frame of fingerprint image.

In another possible design of the second aspect, the obtaining module is configured to obtain the first fingerprint image when a user presses a fingerprint sensor, calculate a first pressure value corresponding to the first fingerprint image, determine a pressure level to which the first pressure value belongs, issue a pressing instruction based on the pressure level to which the first pressure value belongs, where the pressing instruction is used to instruct the user to press the fingerprint sensor with a pressure strength different from the pressure level to which the first pressure value belongs, and obtain the second fingerprint image when the user presses the fingerprint sensor based on the pressing instruction.

In yet another possible design of the second aspect, the obtaining module is specifically configured to collect multiple frames of fingerprint images when a user presses the fingerprint sensor once, where each frame of fingerprint image carries respective collecting time, calculate a pressure value corresponding to each frame of fingerprint image, and obtain, based on the pressure value corresponding to each frame of fingerprint image, the first fingerprint image and the second fingerprint image whose pressure values respectively belong to different pressure levels from the multiple frames of fingerprint images.

In yet another possible design of the second aspect, for any one of the first fingerprint image and the second fingerprint image, the processing module is specifically configured to determine an effective calculation area of the fingerprint image, and determine a pressure value corresponding to the fingerprint image according to a preset corresponding relationship between the area and the pressure value.

Optionally, the processing module is specifically configured to determine an imaging area coefficient of the fingerprint image, determine an actual imaging area in the fingerprint image according to a gray value of each pixel in the fingerprint image and a preset gray threshold, and determine an effective calculation area of the fingerprint image according to the imaging area coefficient and the actual imaging area.

Optionally, the processing module is specifically configured to count the number of imaging pixels in the fingerprint image, where the imaging pixels are pixels with gray values that are not white, and determine the imaging area coefficient of the fingerprint image according to the number of imaging pixels in the fingerprint image and the number of theoretical pixels included in the fingerprint image.

Optionally, the processing module is specifically configured to determine effective pixels in the fingerprint image, where the effective pixels are pixels with a gray value smaller than a preset gray threshold, and determine an actual imaging area in the fingerprint image according to the number of the effective pixels in the fingerprint image.

In yet another possible design of the second aspect, the pressure rating includes: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

Optionally, the processing module is further configured to determine a pressure level to which the first pressure value belongs, determine whether the first fingerprint image is obtained by collecting a real fingerprint when the first pressure value belongs to the first pressure level, determine whether the second pressure value belongs to a second pressure level when the first fingerprint image is obtained by collecting a real fingerprint, and determine whether the second fingerprint image is obtained by collecting a real fingerprint when the second pressure value belongs to the second pressure level.

Optionally, the processing module is further configured to determine a pressure class to which the first pressure value belongs and a pressure class to which the second pressure value belongs, determine whether the first pressure value and the second pressure value belong to different pressure classes, and determine whether the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint when the first pressure value and the second pressure value belong to different pressure classes.

In yet another possible design of the second aspect, for any one of the first fingerprint image and the second fingerprint image, the processing module is further specifically configured to input the fingerprint image into a fingerprint identification model, and determine whether the fingerprint image is obtained by acquiring an authentic fingerprint, where the fingerprint identification model is a model trained in advance for identifying whether the input fingerprint image is obtained by acquiring an authentic fingerprint.

A third aspect of the present application provides a terminal device, comprising a processor, a memory and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the method according to the first aspect as well as possible designs of the first aspect.

A fourth aspect of the present application provides a storage medium having stored therein instructions that, when run on a computer, cause the computer to perform the method as set forth in the first aspect above and in various possible designs of the first aspect.

A fifth aspect of the present application provides a program product comprising instructions which, when run on a computer, cause the computer to perform the method as set forth in the first aspect above and in various possible designs of the first aspect.

A sixth aspect of the present application provides a chip comprising a memory, a processor, the memory storing code and data, the memory being coupled to the processor, the processor executing the code in the memory such that the chip is adapted to perform the method of the first aspect described above and in various possible designs of the first aspect.

The fingerprint identification method, the fingerprint identification device, the terminal equipment and the storage medium provided by the embodiment of the application determine the first pressure value corresponding to the first fingerprint image and the second pressure value corresponding to the second fingerprint image by acquiring the first fingerprint image and the second fingerprint image which are acquired at different moments, the first pressure value and the second pressure value meet different pressure levels, when the first fingerprint image and the second fingerprint image are acquired by acquiring real fingerprints, the successful identification is determined, whether the acquired fingerprint images are acquired by acquiring fake fingerprints can be detected without acquiring fingerprints by using a high-definition optical fingerprint sensor, the cost is reduced, the problem of limitation of the existing size, power consumption and the like is solved, the fingerprint identification safety is improved, and the user experience is improved.

Drawings

Fig. 1 is a flowchart of a first embodiment of a fingerprint identification method according to an embodiment of the present application;

fig. 2 is a schematic flowchart of a second embodiment of a fingerprint identification method according to an embodiment of the present application;

FIG. 3 is a schematic diagram showing the variation of the pressure value and the pressing time in a single pressing process;

fig. 4 is a schematic flowchart of a third embodiment of a fingerprint identification method according to an embodiment of the present application;

fig. 5 is a schematic flowchart of a fourth embodiment of a fingerprint identification method according to an embodiment of the present application;

fig. 6 is a schematic flowchart of a fifth embodiment of a fingerprint identification method according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a first fingerprint image;

FIG. 8 is a schematic diagram of a second fingerprint image;

fig. 9 is a schematic flowchart of a sixth embodiment of a fingerprint identification method according to an embodiment of the present application;

fig. 10 is a schematic flowchart of a seventh embodiment of a fingerprint identification method according to an embodiment of the present application;

FIG. 11 is a schematic structural diagram of an embodiment of a fingerprint identification device according to the present application;

fig. 12 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

With the rapid development of network technology, a terminal device with a high screen occupation ratio becomes an inevitable trend of the development of the current intelligent terminal, but the high screen occupation ratio of the terminal device brings some problems, including the problem of how to set a fingerprint identification sensor with a fingerprint identification function. At present, terminal devices capable of supporting fingerprint identification basically use an optical-based under-screen fingerprint sensor to support fingerprint identification of the terminal device.

Specifically, on the terminal equipment, the optical-based screen lower fingerprint sensor is arranged on the inner side of a display screen of the terminal equipment, the display screen of the terminal equipment emits light when the terminal equipment collects fingerprint information of a user, and light is reflected to the fingerprint sensor through the display screen to form an image so as to obtain a fingerprint image.

However, the false fingerprint film can be divided into a 2D fingerprint film and a 3D fingerprint film, the 2D false fingerprint film means that false fingerprints are on one plane, i.e. the false fingerprint itself is an image, for example, a fingerprint image on a4 paper; the 3D false fingerprint film is a false fingerprint film which is not on a plane and has a 3D structure like a real fingerprint, for example, the false fingerprint film is made of silica gel. Since a lawbreaker may easily collect a user's fingerprint and quickly make a fake fingerprint film to unlock the user's terminal device, property loss and sensitive information leakage are caused. That is, the false fingerprint film made of some materials is very similar to the real fingerprint film of the user, for example, the false fingerprint film made of common materials such as red inkpad, a4 paper, adhesive tape and the like can be used for unlocking the terminal device after experimental verification. And it is very easy to obtain the fingerprint of a certain person from daily life, so that the optical fingerprint under the display screen faces a great safety risk, and the problem that the terminal equipment is illegally unlocked by a malicious user exists.

For the problem, the optical fingerprint anti-counterfeiting scheme in the prior art judges a single image, for example, a high-definition optical fingerprint sensor is used for collecting a fingerprint, information of sweat pores and sweat in the high-definition fingerprint image is analyzed to judge whether the fingerprint image is obtained by collecting a real fingerprint, if the fingerprint image contains the information of the sweat pores and the sweat, the fingerprint image is determined to be obtained by collecting the real fingerprint, and if the fingerprint image does not contain the information of the sweat pores and the sweat, the fingerprint image is determined not to be obtained by collecting the real fingerprint. However, this solution requires high image definition, and requires the use of a high-definition optical fingerprint sensor, and in addition, due to the limitation of the volume of the terminal device, the high-definition optical fingerprint sensor is not suitable for being applied to small-sized terminal devices such as mobile phones and tablet computers.

For example, in the prior art, a deep learning model based on a convolutional neural network may also be trained through the collected real fingerprint image and the fake fingerprint image, so as to determine whether the collected fingerprint image is obtained by collecting a real fingerprint. However, false fingerprints made of some materials can be quite similar to a true fingerprint image when a single image is collected, and are not easy to distinguish, so that the safety cannot be guaranteed.

In addition, in traditional electric capacity fingerprint identification scheme, can also adopt the anti-fake scheme of fingerprint based on blood and rhythm of the heart signal, this need add special sensor in addition and gather blood and rhythm of the heart signal, when discerning the fingerprint, whether the fingerprint of discernment is true fingerprint through signals such as blood flow and rhythm of the heart that judge whether can detect, however, to the fingerprint identification scene under the display screen under, it has very big technical difficulty to add the sensor of gathering signals such as blood flow and rhythm of the heart, the cost also can show the increase, can't carry out wide application.

Further, in the prior art, especially for small-sized portable terminal devices such as mobile phones, it is necessary to implement a fingerprint anti-counterfeiting scheme, which includes that the acquired fingerprint image is a partial image rather than a whole fingerprint, a model storage space is limited, a computing resource is limited, and a computing time is limited.

The embodiment of the application provides a fingerprint identification method aiming at the potential safety hazard problem existing in the fingerprint identification scheme in the prior art, a first pressure value corresponding to a first fingerprint image and a second pressure value corresponding to a second fingerprint image are determined by acquiring the first fingerprint image and the second fingerprint image which are acquired at different moments, different pressure levels are met at the first pressure value and the second pressure value, and when the first fingerprint image and the second fingerprint image are both acquired by acquiring real fingerprints, the successful identification is determined, whether the acquired fingerprint images are acquired by acquiring fake fingerprints can be detected without acquiring fingerprints by using a high-definition optical fingerprint sensor, the cost is reduced, the problem that the existing size, the power consumption and the like are limited is solved, the fingerprint identification safety is improved, and the user experience is improved.

It can be understood that the execution subject in the embodiment of the present application may be a terminal device with a fingerprint identification function, for example, a mobile phone with an optical fingerprint sensor, a tablet computer, an attendance terminal, a fingerprint door lock, or other devices, and the present application embodiment does not limit the terminal device to which the execution subject is applicable, and may be determined according to actual situations.

The technical solution of the present application will be described in detail by specific examples. It should be noted that the following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. Embodiments of the present application will be described below with reference to the accompanying drawings.

In the embodiments of the present application, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Fig. 1 is a flowchart of a first embodiment of a fingerprint identification method according to an embodiment of the present application. As shown in fig. 1, the fingerprint identification method provided in the embodiment of the present application may include the following steps:

step 11: acquiring a first fingerprint image and a second fingerprint image which are acquired at different moments.

In the embodiment of the application, the terminal device is provided with the optical fingerprint sensor, and when the user has an identification request, the user sends the identification request by pressing the optical fingerprint sensor on the terminal device, so that the terminal device acquires a fingerprint image to be identified based on the acquired identification request of the user and according to the identification request.

Exemplarily, optical fingerprint sensor in this embodiment is optical fingerprint module under the screen, and it is used for gathering fingerprint image, and the characteristic that probably possesses is gather multiframe fingerprint image in the short time.

In practical applications, any kind of false fingerprint can show different characteristics from a live fingerprint under the pressing action of different pressures. The living fingerprint corresponds to different fingerprint images under different pressing pressures, the fingerprint image corresponding to the two-dimensional 2D false fingerprint basically does not change when the pressing pressure changes, and the fingerprint image corresponding to the three-dimensional 3D false fingerprint under different pressing pressures and the living fingerprint have different effects. Therefore, in the embodiment of the application, based on the above features of the fake fingerprint and the live fingerprint, when the user presses the optical fingerprint sensor of the terminal device, the optical fingerprint sensor may capture a plurality of fingerprint images at different times, so that the terminal device may capture the first fingerprint image and the second fingerprint image captured at different times.

It is worth mentioning that, in the embodiment of the present application, the acquisition time interval of the first fingerprint image and the second fingerprint image satisfies the preset time interval threshold.

Specifically, each fingerprint image acquired by the optical fingerprint sensor corresponds to an acquisition time, and therefore, in this embodiment, in order to ensure that two fingerprint images acquired by the terminal device are obtained by acquiring a real fingerprint, the acquisition time interval between the first fingerprint image and the second fingerprint image satisfies a preset time interval threshold.

Illustratively, the acquisition time of the first fingerprint image and the acquisition time of the second fingerprint image cannot be greater than a preset time interval threshold, so as to ensure the security of the terminal device for fingerprint identification.

Step 12: and determining a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image.

Because the fingerprint of the user has different lines, the ridge areas of the fingerprint images with different pressing force degrees are different, and the area occupied by the ridge of the fingerprint image with the larger pressing force degree is larger. Therefore, in this embodiment, by analyzing the actual calculated areas of the first fingerprint image and the second fingerprint image, the first pressure value corresponding to the first fingerprint image and the second pressure value corresponding to the second fingerprint image can be determined.

The implementation principle of this step can be referred to the following description in the embodiment shown in fig. 6, and is not described here again.

Step 13: when the first pressure value and the second pressure value meet different pressure levels and the first fingerprint image and the second fingerprint image are both obtained by collecting real fingerprints, the successful identification is determined.

Wherein the pressure rating comprises: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

In practical application, the optical underscreen fingerprint identification scheme on the existing terminal equipment is easily broken by a fake fingerprint film made of cheap materials by lawbreakers, so that great potential safety hazards are brought to consumers. Therefore, the first fingerprint image and the second fingerprint image which are acquired under different pressing strength can be utilized, whether the pressure values corresponding to the first fingerprint image and the second fingerprint image meet different pressure levels or not is judged to ensure that the user can press the fingerprint sensor under different pressing strength, and the acquired fingerprint image is ensured to be from a living body by judging that the first fingerprint image and the second fingerprint image are both acquired by acquiring real fingerprints.

Specifically, the terminal device collects a first fingerprint image and a second fingerprint image of a user fingerprint at different moments and under different pressing force degrees, firstly judges whether the obtained first fingerprint image and the obtained second fingerprint image accord with the pressing force degrees, then judges whether the first fingerprint image and the second fingerprint image under the different pressing force degrees are both obtained by collecting real fingerprints, and only determines that a user sending an identification request is a legal user if both the first fingerprint image and the second fingerprint image are obtained by collecting real fingerprints.

According to the fingerprint identification method provided by the embodiment of the application, the first fingerprint image and the second fingerprint image which are acquired at different moments are acquired, the first pressure value corresponding to the first fingerprint image and the second pressure value corresponding to the second fingerprint image are determined, different pressure levels are met at the first pressure value and the second pressure value, when the first fingerprint image and the second fingerprint image are acquired by acquiring real fingerprints, the successful identification is determined, whether the acquired fingerprint images are acquired by acquiring fake fingerprints can be detected without acquiring fingerprints by using a high-definition optical fingerprint sensor, the cost is reduced, the problem of limitation of the existing size, power consumption and the like is solved, the fingerprint identification safety is improved, and the user experience is improved.

For example, in a possible design of the embodiment of the present application, fig. 2 is a schematic flowchart of a second embodiment of a fingerprint identification method provided in the embodiment of the present application. As shown in fig. 2, in the embodiment of the present application, the step 11 may be implemented by:

step 21: gather multiframe fingerprint image when user's single pressed fingerprint sensor, each frame fingerprint image carries respective collection time and collection pressure value.

For example, in the embodiment of the application, for a certain type of terminal device, the terminal device is provided with a pressure fingerprint sensor, which can record the variation trend of the pressure value and the pressing time of a user in a single pressing process, and acquire multiple frames of fingerprint images, wherein each frame of fingerprint image carries the respective acquisition time and acquisition pressure value.

For example, fig. 3 is a schematic diagram of the variation of the pressure value and the pressing time in a single pressing process. As shown in fig. 3, the pressure fingerprint sensor may collect multiple frames of fingerprint images during a single pressing process of the user, for example, as shown in fig. 3, 5 frames of fingerprint images may be collected during a single pressing process, where each frame of fingerprint image carries a collection time and a collection pressure value.

Step 22: and acquiring a first fingerprint image and a second fingerprint image from the multiple fingerprint images based on the acquisition time and the acquisition pressure value carried by each fingerprint image.

In this embodiment, after acquiring multiple frames of fingerprint images, the terminal device may select two fingerprint images satisfying the pressure condition from the acquired multiple frames of fingerprint images based on the acquisition time and the acquisition pressure value carried by each frame of fingerprint image.

Specifically, the terminal device selects one fingerprint image with a pressure value meeting a first pressure level from multiple fingerprint images according to the acquisition time and the acquisition pressure value carried by each fingerprint image, calculates the pressure value corresponding to the fingerprint image based on the gray value of each pixel in the fingerprint image and the size area of the fingerprint image, judges whether the pressure value corresponding to the fingerprint image meets the first pressure level, and determines that the fingerprint image is the first fingerprint image if the pressure value meets the first pressure level.

And similarly, selecting one frame of fingerprint image with a pressure value meeting the second pressure level from the multiple fingerprint images based on the acquisition time and the acquisition pressure value carried by each frame of fingerprint image, then calculating the pressure value corresponding to the fingerprint image, judging whether the pressure value corresponding to the fingerprint image meets the second pressure level, and if so, determining that the fingerprint image is the second fingerprint image.

Further, in order to ensure the security of fingerprint identification of the terminal device, the time interval between the collection times of the first fingerprint image and the second fingerprint image determined above needs to satisfy a preset time interval threshold.

Specifically, the acquisition time interval of the first fingerprint image and the acquisition time of the second fingerprint image are calculated according to the acquisition time of the first fingerprint image and the acquisition time of the second fingerprint image, then whether the acquisition time interval is smaller than a preset time interval threshold value or not is judged, and if yes, the first fingerprint image and the second fingerprint image are determined to meet the requirements.

According to the fingerprint identification method provided by the embodiment of the application, a plurality of frames of fingerprint images are acquired when a user presses a fingerprint sensor once, each frame of fingerprint image carries respective acquisition time and acquisition pressure value, and a first fingerprint image and a second fingerprint image are acquired from the plurality of frames of fingerprint images based on the acquisition time and the acquisition pressure value carried by each frame of fingerprint image. That is, press down alright determine the first fingerprint image and the second fingerprint image that meet the requirements through user's single, need not additionally to increase the sensor, only utilize current fingerprint sensor alright realize fingerprint image's collection, save the cost, the technological problem of having avoided increasing fingerprint sensor under the display screen, can detect false fingerprint membrane of 2D and the false fingerprint membrane of 3D more effectively, the discernment security of increase, in addition, need not the user and carry out additional operation, only need normally to use the fingerprint to verify, user experience has been improved.

For example, in another possible design of the embodiment of the present application, fig. 4 is a schematic flowchart of a third embodiment of a fingerprint identification method provided in the embodiment of the present application. As shown in fig. 4, in the embodiment of the present application, the step 11 may be implemented by:

step 41: a first fingerprint image of a user pressing a fingerprint sensor is acquired.

For example, in this embodiment, for some terminal devices, the fingerprint sensor can only acquire one fingerprint image during a single pressing process of the user, so that the user is required to perform two pressing processes if two fingerprint images with different pressing pressures are to be acquired.

Specifically, the terminal device acquires a first fingerprint image of the user in a single pressing process by using the fingerprint sensor. Optionally, the terminal device further records the acquisition time of the first fingerprint image, so that when the terminal device acquires the second fingerprint image, the acquisition time and the acquisition time of the second fingerprint image are used to determine whether the acquisition time of the two fingerprint images meets the time requirement.

Step 42: and calculating a first pressure value corresponding to the first fingerprint image, and determining the pressure grade to which the first pressure value belongs.

Optionally, after the terminal device acquires the first fingerprint image, the terminal device first acquires the gray value of each pixel in the first fingerprint image, and determines the first pressure value based on the gray values of all pixels in the first fingerprint image.

For example, in this embodiment, a first pressure level and a second pressure level are preset in the terminal device, a pressure value smaller than the first pressure threshold belongs to the first pressure level, a pressure value larger than the second pressure threshold belongs to the second pressure level, and the second pressure threshold is larger than the first pressure threshold.

In this embodiment, the pressure class to which the first pressure value belongs is determined by comparing the first pressure value with the first pressure threshold and the second pressure threshold, that is, if the first pressure value is less than or equal to the first pressure threshold, it is determined that the first pressure value belongs to the first pressure class, if the first pressure value is greater than or equal to the second pressure threshold, it is determined that the first pressure value belongs to the second pressure class, and if the first pressure value is between the first pressure threshold and the second pressure threshold, it is determined that the first pressure value does not meet the pressure requirement, and the first pressure value is discarded.

Step 43: and sending a pressing indication based on the pressure grade to which the first pressure value belongs, wherein the pressing indication is used for indicating a user to press the fingerprint sensor with a pressure strength different from the pressure grade to which the first pressure value belongs.

In this embodiment, in order to acquire two fingerprint images satisfying different pressure levels, after determining the level pressure to which the first pressure value corresponding to the first fingerprint image belongs, a pressure instruction may be issued to instruct a user to press the fingerprint sensor according to a pressing force degree different from the first pressure value, so as to acquire a second fingerprint image whose pressure level satisfies a requirement.

For example, in this embodiment, the terminal device may issue the pressing instruction in a voice manner, for example, issue "please press with gravity" when it is determined that the first pressure value belongs to the first pressure level, issue "please press with light force" when it is determined that the first pressure value belongs to the second pressure level, and so on.

Optionally, the terminal device may further send a press prompt in a text manner, for example, by displaying "please press with gravity" or "please press with light force" on the user interaction interface, the user is prompted to press with corresponding force.

Step 44: a second fingerprint image of the user when pressing the fingerprint sensor based on the press indication is acquired.

In this embodiment, after the user obtains the pressing instruction sent by the terminal device, the user can press the fingerprint sensor according to the pressing instruction, so that the terminal device can obtain the second fingerprint image acquired by the fingerprint sensor.

It should be noted that after the second fingerprint image is acquired, the terminal device further needs to determine a second pressure value corresponding to the second fingerprint image according to the gray value of each pixel in the second fingerprint image, and then determines whether the second pressure value and the first pressure value belong to different pressure levels, if yes, it is determined that the acquired second fingerprint image meets the pressure requirement, otherwise, it is determined that the acquired second fingerprint image does not meet the pressure requirement, and the second fingerprint image needs to be acquired again.

Further, in order to ensure the security of fingerprint identification of the terminal device, in the embodiment of the present application, it is also necessary to determine that the acquired collection time interval between the first fingerprint image and the second fingerprint image needs to meet a preset time interval threshold. For implementation of the judgment, reference may be made to the descriptions of the above embodiments, which are not described herein again.

According to the fingerprint identification method provided by the embodiment of the application, the first fingerprint image when the user presses the fingerprint sensor is obtained, the first pressure value corresponding to the first fingerprint image is calculated, the pressure grade to which the first pressure value belongs is determined, the pressing indication is sent based on the pressure grade to which the first pressure value belongs, the pressing indication is used for indicating the user to press the fingerprint sensor with pressure force different from the pressure grade to which the first pressure value belongs, and finally the second fingerprint image when the user presses the fingerprint sensor based on the pressing indication is obtained. In the technical scheme, the function of the fingerprint sensor is not limited, and only the user needs to press twice based on the press prompt, so that the implementation scheme is simple and easy to implement.

For example, in yet another possible design of the embodiment of the present application, fig. 5 is a schematic flowchart of a fourth embodiment of a fingerprint identification method provided in the embodiment of the present application. As shown in fig. 5, in the embodiment of the present application, the step 11 may be implemented by:

step 51: the method comprises the steps of collecting multi-frame fingerprint images when a user presses a fingerprint sensor once, wherein each frame of fingerprint image carries respective collection time.

Optionally, for some fingerprint sensors only having the function of acquiring multiple fingerprint images, the terminal device may acquire multiple fingerprint images during a single pressing process of the user, but because the terminal device does not have a pressure detection function, in this embodiment, the terminal device acquires multiple fingerprint images through the fingerprint sensor, where each fingerprint image may carry respective acquisition time.

Step 52: and calculating the pressure value corresponding to each frame of fingerprint image.

Optionally, in this embodiment, a pressure value corresponding to each frame of fingerprint image may be calculated by a certain pressure detection method. For example, the corresponding pressure value is determined by the gray value of each pixel in each frame of the fingerprint image.

For the implementation principle of this step, reference may be made to the following description of the embodiment shown in fig. 6, and details are not described here.

Step 53: and acquiring a first fingerprint image and a second fingerprint image of which the pressure values belong to different pressure levels respectively from the multiple fingerprint images based on the pressure value corresponding to each fingerprint image.

In this embodiment, after the terminal device obtains the pressure value corresponding to each frame of fingerprint image, it may directly obtain two fingerprint images respectively belonging to different pressure levels from the multiple frames of fingerprint images based on the pressure value of each frame of fingerprint image, for example, a first pressure value corresponding to a first fingerprint image belongs to a first pressure level, and a pressure value corresponding to a second fingerprint image belongs to a second pressure level; or the first pressure value corresponding to the first fingerprint image belongs to the second pressure level, and the pressure value corresponding to the second fingerprint image belongs to the first pressure level.

According to the fingerprint identification method provided by the embodiment of the application, multiple frames of fingerprint images are acquired when a user presses a fingerprint sensor once, each frame of fingerprint image carries respective acquisition time, the pressure value corresponding to each frame of fingerprint image is calculated, and the first fingerprint image and the second fingerprint image of which the pressure values belong to different pressure levels are acquired from the multiple frames of fingerprint images based on the pressure value corresponding to each frame of fingerprint image. According to the technical scheme, the multi-frame images can be acquired through single pressing of the user, the first fingerprint image and the second fingerprint image which meet the requirements are determined through calculating the pressure value of each frame of fingerprint image, and the implementation scheme is simple.

Exemplarily, on the basis of any of the above embodiments, fig. 6 is a schematic flowchart of a fifth embodiment of a fingerprint identification method provided in the embodiment of the present application. As shown in fig. 6, in the embodiment of the present application, for any one of the first fingerprint image and the second fingerprint image, determining the pressure value corresponding to the fingerprint image may be implemented by:

step 61: an effective calculated area of the fingerprint image is determined.

In this embodiment, the fingerprint image is a gray scale map, and each pixel in the fingerprint image can be represented by a gray scale value, where the gray scale value of black is 0 and the gray scale value of white is 255. Thus, the grayscale value of each pixel in the fingerprint image may be represented by one of a range of grayscale values [0, 255], where the greater the grayscale value, the more white the grayscale value of the pixel is.

Illustratively, for a fingerprint image img [ h, w ] having an image height h and an image width w, the range of gray scale values for the pixel at the (i, j) position is [0, 255], where 0 ≦ i ≦ h-1 and 0 ≦ j ≦ w-1.

In this embodiment, if a pressure value corresponding to each fingerprint image is to be calculated, an imaging area coefficient of the fingerprint image is first determined, an actual imaging area in the fingerprint image is determined according to a gray value of each pixel in the fingerprint image and a preset gray threshold, and an effective calculation area of the fingerprint image is determined according to the imaging area coefficient and the actual imaging area.

Illustratively, in this embodiment, the determining the imaging area coefficient of the fingerprint image specifically includes the following steps:

a1: and counting the number of imaging pixels in the fingerprint image, wherein the imaging pixels refer to pixels with gray values not being white.

In this embodiment, since some white unimaged portions may be included in the fingerprint image, the present embodiment may determine the number of imaged pixels in the fingerprint image by the gray-scale values of black and white.

Specifically, since the gray scale value of black is 0 and the gray scale value of white is 255, it is possible to determine whether each pixel in the fingerprint image is an imaged pixel based on whether the gray scale value of it is not 255. Specifically, if the gradation value of the pixel at the img (i, j) position is 255, the pixel is not the imaging pixel, and if the gradation value of the pixel at the img (i, j) position is 255, the pixel is not the imaging pixel.

Illustratively, the following expression q (x) denotes whether the pixel at the img (i, j) position is imaged, and the formula is as follows:

accordingly, the fingerprint image img [ h, w ]]The number of imaging pixels can be expressed as

A2: and determining the imaging area coefficient of the fingerprint image according to the number of the imaging pixels in the fingerprint image and the number of theoretical pixels included in the fingerprint image.

Illustratively, in the present embodiment, for a fingerprint image img [ h, w ] having an image height h and an image width w, the number of theoretical pixels (i.e., the theoretical area) included in the fingerprint image img [ h, w ] is h × w. Thus, the imaging area coefficient k of the fingerprint image img [ h, w ] can be expressed by the following formula:

for example, in this embodiment, the determining the actual imaging area in the fingerprint image according to the grayscale value of each pixel in the fingerprint image and the preset grayscale threshold may be implemented by:

b1: and determining effective pixels in the fingerprint image, wherein the effective pixels refer to pixels with the gray values smaller than a preset gray threshold value.

In this embodiment, a preset grayscale threshold may be set in the terminal device, and after the grayscale value of each pixel in the fingerprint image is obtained, whether each pixel is an effective pixel is determined by determining a size relationship between the grayscale value of each pixel and the preset grayscale threshold.

Illustratively, when the gray value of a certain pixel of the fingerprint image is less than the preset gray threshold t, the pixel is considered as an effective pixel. Alternatively, whether the pixel at the img (i, j) position is an effective pixel is expressed by p (x) as follows:

b2: and determining the actual imaging area in the fingerprint image according to the number of the effective pixels in the fingerprint image.

In the present embodiment, for a fingerprint image img [ h, w ] with an image height h and an image width w]The fingerprint image img [ h, w]The number of the middle effective pixels, namely the actual imaging area in the fingerprint image can be expressed as

Accordingly, in the embodiment of the present application, the effective calculated area of the fingerprint image may be determined according to the calculated imaging area coefficient and the actual imaging area.

Specifically, the effective calculation area a of the fingerprint image can be represented by the following formula:

it should be noted that, the effective calculation area of the fingerprint image can be obtained by using the above calculation method for the pressure values of the first fingerprint image and the second fingerprint image. The effective areas of the fingerprint images are different under different pressing force degrees.

For example, fig. 7 is a schematic diagram of the texture of the first fingerprint image. Fig. 8 is a schematic diagram of the texture of the second fingerprint image. A first pressure value corresponding to the first fingerprint image belongs to a first pressure grade, and a second pressure value corresponding to the second fingerprint image belongs to a second pressure grade. Illustratively, as shown in fig. 7 and 8, when the preset grayscale threshold t is equal to 100, the effective calculated area of the first fingerprint image obtained by the implementation of step 51 is 4516, and the effective calculated area of the second fingerprint image is 5426.

Step 62: and determining a pressure value corresponding to the fingerprint image according to the corresponding relation between the preset area and the pressure value.

In this embodiment, the terminal device stores the corresponding relationship between the area and the pressure value in advance, so that after the terminal device obtains the effective calculated area of the fingerprint image, the pressure value corresponding to the effective calculated area, that is, the pressure value corresponding to the fingerprint image, can be determined by querying the preset corresponding relationship between the area and the pressure value.

For example, according to the effective calculated area in the first fingerprint image and the corresponding relationship between the preset area and the pressure value, the pressure value corresponding to the first fingerprint image may be determined. And determining the pressure value corresponding to the second fingerprint image according to the effective calculation area in the second fingerprint image and the corresponding relation between the preset area and the pressure value.

The fingerprint identification method provided by the embodiment of the application determines the imaging area coefficient of the fingerprint image by counting the number of imaging pixels in the fingerprint image, wherein the imaging pixels are pixels with gray values not being white, and determines the imaging area coefficient of the fingerprint image according to the number of the imaging pixels in the fingerprint image and the number of theoretical pixels included in the fingerprint image. In the technical scheme, the corresponding pressure value range can be calculated according to the fingerprint image, the obtained pressure value is accurate, and a foundation is laid for subsequent accurate fingerprint identification.

As an example, on the basis of the foregoing embodiments, fig. 9 is a schematic flowchart of a sixth embodiment of a fingerprint identification method provided in this application embodiment. As shown in fig. 9, in the embodiment of the present application, the method may further include the steps of:

step 91: and determining the pressure grade to which the first pressure value belongs.

Optionally, in an embodiment of the present application, after obtaining a first pressure value corresponding to the first fingerprint image, a relationship between the first pressure value and a first pressure threshold and a second pressure threshold is determined.

For example, if the first pressure value is less than or equal to the first pressure threshold, it is determined that the first pressure value corresponding to the first fingerprint image belongs to the first pressure level; and if the first pressure value is greater than or equal to the second pressure threshold value, determining that the first pressure value corresponding to the first fingerprint image belongs to the second pressure level. And if the first pressure value is larger than the first pressure threshold value and smaller than the second pressure threshold value, determining that the first fingerprint image does not meet the acquisition requirement, and discarding the first fingerprint image.

And step 92: and when the first pressure value belongs to the first pressure level, judging whether the first fingerprint image is obtained by acquiring a real fingerprint.

Optionally, as an example, if the first pressure value belongs to the first pressure level, it may be first detected whether the first fingerprint image is obtained by acquiring a real fingerprint, and then it is determined whether to judge the pressure level to which the second pressure value belongs according to a detection result of the first fingerprint image.

Step 93: and when the first fingerprint image is obtained by collecting the real fingerprint, judging whether the second pressure value belongs to a second pressure grade.

For example, in this embodiment, when the first fingerprint image is obtained by acquiring an authentic fingerprint, it may be determined whether the second pressure value belongs to the second pressure level. When the first fingerprint image is not obtained by collecting the real fingerprint, the first fingerprint image can be directly abandoned, and the fingerprint identification is determined to fail.

Step 94: and when the second pressure value belongs to the second pressure level, judging whether the second fingerprint image is obtained by acquiring the real fingerprint.

In this embodiment, when the first fingerprint image is obtained by collecting the real fingerprint and the second pressure value belongs to the second pressure level, whether the second fingerprint image is obtained by collecting the real fingerprint is determined by judging again, and whether the identification is successful is determined according to the judgment result of the second fingerprint image.

According to the fingerprint identification method provided by the embodiment of the application, whether the first fingerprint image is obtained by collecting the real fingerprint or not is judged by determining the pressure grade to which the first pressure value belongs when the first pressure value belongs to the first pressure grade, whether the second pressure value belongs to the second pressure grade or not is judged when the first fingerprint image is obtained by collecting the real fingerprint, and whether the second fingerprint image is obtained by collecting the real fingerprint or not is judged when the second pressure value belongs to the second pressure grade. In the technical scheme, after the pressure value judgment and the judgment of the true and false fingerprints from the collected first fingerprint image are carried out, the pressure value judgment and the judgment of the true and false fingerprints from the second fingerprint image are carried out only when the first fingerprint image is successfully identified, and the implementation mode is simple, easy to realize and capable of improving the identification efficiency and the identification safety.

As another example, on the basis of the foregoing embodiments, fig. 10 is a flowchart illustrating a seventh embodiment of a fingerprint identification method according to the present application. As shown in fig. 10, in an embodiment of the present application, the method may further include the steps of:

step 101: and determining the pressure grade of the first pressure value and the pressure grade of the second pressure value.

In an embodiment of the application, after acquiring two fingerprint images, for example, a first fingerprint image and a second fingerprint image, a terminal device determines a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image, and determines a relationship between the first pressure value and a first pressure threshold and a second pressure threshold, and a relationship between the second pressure value and the first pressure threshold and the second pressure threshold, respectively, so as to determine a pressure level to which the first pressure value belongs and a pressure level to which the second pressure value belongs.

Step 102: and judging whether the first pressure value and the second pressure value belong to different pressure levels.

For example, if the first pressure value is less than or equal to the first pressure threshold and the second pressure value is greater than or equal to the second pressure threshold, or if the first pressure value is greater than or equal to the second pressure threshold and the second pressure value is less than or equal to the first pressure threshold, it is determined that the first pressure value corresponding to the first fingerprint image and the second pressure value corresponding to the second fingerprint image belong to different pressure levels, otherwise, it is determined that the first fingerprint image and/or the second fingerprint image do not meet the acquisition requirement of the image, the first fingerprint image and/or the second fingerprint image are discarded, and the fingerprint image is acquired again.

Step 103: and when the first pressure value and the second pressure value belong to different pressure levels, judging whether the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint.

As an example, when it is determined that the first pressure value and the second pressure value belong to different pressure levels based on step 102, it is determined whether the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint, and it is determined whether the identification is successful according to the determination result of the first fingerprint image and the second fingerprint image.

It will be appreciated that successful identification is only determined if both the first fingerprint image and the second fingerprint image were obtained from the acquisition of a true fingerprint, otherwise the identification is determined to have failed.

According to the fingerprint identification method provided by the embodiment of the application, whether the first pressure value and the second pressure value belong to different pressure levels is judged by determining the pressure level to which the first pressure value belongs and the pressure level to which the second pressure value belongs, and whether the first fingerprint image and the second fingerprint image are obtained by collecting real fingerprints is judged when the first pressure value and the second pressure value belong to different pressure levels. In the technical scheme, the pressure value of the two collected fingerprint images is judged, if the two fingerprint images meet the pressure requirement, the true and false fingerprint judgment is executed, the realization mode is easy to realize, and the identification efficiency and the identification safety can be ensured.

Illustratively, on the basis of the embodiments shown in fig. 9 and 10, for any one of the first fingerprint image and the second fingerprint image, determining whether the fingerprint image is obtained by acquiring an authentic fingerprint may be implemented by:

Specifically, in this embodiment, for the first fingerprint image, the first fingerprint image is input to the fingerprint identification model, and whether the first fingerprint image is obtained by collecting a real fingerprint is determined. Similarly, for the second fingerprint image, the second fingerprint image is input into the fingerprint identification model, and whether the second fingerprint image is obtained by collecting a real fingerprint is judged. The method may detect whether the input fingerprint image is from a live fingerprint.

In this embodiment, the terminal device first collects a plurality of true fingerprint images obtained by collecting a true fingerprint and false fingerprint images obtained by collecting a false fingerprint, and trains the deep learning model based on the true fingerprint images, the false fingerprint images and the convolutional neural network, so as to finally obtain a trained fingerprint identification model. When the fingerprint identification model is used, a fingerprint image needing to be judged is input into the fingerprint identification model, and a judgment result is determined according to the output of the fingerprint identification model.

It should be noted that, in practical applications, the terminal device may first acquire a first fingerprint image when the user presses the finger based on the first pressing force (e.g., light force), and determine whether the acquired first fingerprint image meets a pressing requirement of the first pressing force. And if the obtained first fingerprint image meets the requirement of pressing by the first pressing force, executing judgment on whether the first fingerprint image is obtained by collecting a real fingerprint. If the first fingerprint image is determined to be obtained by collecting the real fingerprint, a second fingerprint image when the user presses the finger based on a second pressing force (for example, the gravity) is obtained, whether the obtained second fingerprint image meets the pressing requirement of the second pressing force is judged, and if yes, whether the second fingerprint image is obtained by collecting the real fingerprint is judged. When the first fingerprint image and the second fingerprint image are determined to meet the requirement of the pressing strength and are acquired by collecting the real fingerprint, the successful identification is determined, so that the safety of fingerprint identification is ensured.

In this embodiment, when determining whether the first fingerprint image meets the requirement of the first pressing force degree press and determining whether the second fingerprint image meets the requirement of the second pressing force degree press, it is necessary to obtain the pressure value corresponding to the fingerprint image from the fingerprint image itself according to the steps of the embodiment shown in fig. 6. By the method, a lawbreaker can be prevented from using an unsatisfactory fake fingerprint deception system for fingerprint identification.

Optionally, the implementation manner of determining whether the first fingerprint image is obtained by collecting a real fingerprint and determining whether the second fingerprint image is obtained by collecting a real fingerprint may be that a true and false fingerprint determination model based on a convolutional neural network is input to the fingerprint image, and the model determines whether the fingerprint is obtained by collecting a real fingerprint. It is understood that the true and false fingerprint judgment model is a model trained in advance based on a historical fingerprint image for identifying whether an input fingerprint image is obtained by acquiring a true fingerprint.

Further, in the embodiment of the application, when the first fingerprint image and the second fingerprint image are collected, the fingerprint image carries the collection time, and it is ensured that the time interval of the collection time of the first fingerprint image and the collection time of the second fingerprint image is smaller than a preset time interval threshold value, so that the security of the fingerprint identification of the terminal device is ensured.

Fig. 11 is a schematic structural diagram of an embodiment of a fingerprint identification device according to the present application. The device can be integrated in the terminal equipment and can also be realized by the terminal equipment. As shown in fig. 11, the apparatus may include: an acquisition module 111, a processing module 112 and a determination module 113.

The acquiring module 111 is configured to acquire a first fingerprint image and a second fingerprint image acquired at different times;

the processing module 112 is configured to determine a first pressure value corresponding to the first fingerprint image and a second pressure value corresponding to the second fingerprint image;

the determining module 113 is configured to determine that the identification is successful when the first pressure value and the second pressure value satisfy different pressure levels and both the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint.

For example, in this embodiment, the acquisition time interval between the first fingerprint image and the second fingerprint image satisfies a preset time interval threshold.

For example, in a possible design of this embodiment, the obtaining module 111 has a function of collecting multiple frames of fingerprint images when the user presses the fingerprint sensor once, each frame of fingerprint image carries a respective collecting time and collecting pressure value, and based on the collecting time and collecting pressure value carried by each frame of fingerprint image, the first fingerprint image and the second fingerprint image are obtained from the multiple frames of fingerprint images.

For example, in another possible design of this embodiment, the obtaining module 111 is configured to obtain the first fingerprint image when a user presses a fingerprint sensor, calculate a first pressure value corresponding to the first fingerprint image, determine a pressure level to which the first pressure value belongs, issue a pressing instruction based on the pressure level to which the first pressure value belongs, where the pressing instruction is used to instruct the user to press the fingerprint sensor with a pressure strength different from the pressure level to which the first pressure value belongs, and obtain the second fingerprint image when the user presses the fingerprint sensor based on the pressing instruction.

For example, in another possible design of this embodiment, the obtaining module 111 is specifically configured to collect multiple frames of fingerprint images when a user presses a fingerprint sensor once, where each frame of fingerprint image carries a respective collecting time, calculate a pressure value corresponding to each frame of fingerprint image, and obtain, based on the pressure value corresponding to each frame of fingerprint image, the first fingerprint image and the second fingerprint image whose pressure values respectively belong to different pressure levels from the multiple frames of fingerprint images.

For example, in any possible design of the embodiment of the present application, for any one of the first fingerprint image and the second fingerprint image, the processing module 112 is specifically configured to determine an effective calculation area of the fingerprint image, and determine a pressure value corresponding to the fingerprint image according to a preset corresponding relationship between the area and the pressure value.

Optionally, the processing module 112 is specifically configured to determine an imaging area coefficient of the fingerprint image, determine an actual imaging area in the fingerprint image according to a gray value of each pixel in the fingerprint image and a preset gray threshold, and determine an effective calculation area of the fingerprint image according to the imaging area coefficient and the actual imaging area.

In this embodiment, the processing module 112 is specifically configured to count the number of imaging pixels in the fingerprint image, where the imaging pixels are pixels with gray values that are not white, and determine the imaging area coefficient of the fingerprint image according to the number of imaging pixels in the fingerprint image and the number of theoretical pixels included in the fingerprint image.

In this embodiment, the processing module 112 is specifically configured to determine effective pixels in the fingerprint image, where the effective pixels are pixels with a gray value smaller than a preset gray threshold, and determine an actual imaging area in the fingerprint image according to the number of the effective pixels in the fingerprint image.

Illustratively, in one possible design of this embodiment, the pressure levels include: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

As an example, the processing module 112 is further configured to determine a pressure level to which the first pressure value belongs, determine whether the first fingerprint image is obtained by capturing an authentic fingerprint when the first pressure value belongs to the first pressure level, determine whether the second pressure value belongs to the second pressure level when the first fingerprint image is obtained by capturing an authentic fingerprint, and determine whether the second fingerprint image is obtained by capturing an authentic fingerprint when the second pressure value belongs to the second pressure level.

As another example, the processing module 112 is further configured to determine a pressure level to which the first pressure value belongs and a pressure level to which the second pressure value belongs, determine whether the first pressure value and the second pressure value belong to different pressure levels, and determine whether the first fingerprint image and the second fingerprint image are obtained by acquiring a real fingerprint when the first pressure value and the second pressure value belong to different pressure levels.

In any of the foregoing possible designs of the embodiment of the present application, for any one of the first fingerprint image and the second fingerprint image, the processing module 112 is further specifically configured to input the fingerprint image into a fingerprint identification model, and determine whether the fingerprint image is obtained by acquiring a real fingerprint, where the fingerprint identification model is a pre-trained model for identifying whether the input fingerprint image is obtained by acquiring a real fingerprint.

The fingerprint identification apparatus of this embodiment may be used to execute the implementation schemes of the method embodiments shown in fig. 1 to fig. 10, and the specific implementation manner and the technical effect are similar and will not be described again here.

It should be noted that the division of the modules of the above apparatus is only a logical division, and the actual implementation may be wholly or partially integrated into one physical entity, or may be physically separated. And these modules can be realized in the form of software called by processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of calling software by the processing element, and part of the modules can be realized in the form of hardware. For example, the determining module may be a processing element separately set up, or may be implemented by being integrated in a chip of the apparatus, or may be stored in a memory of the apparatus in the form of program code, and the function of the determining module is called and executed by a processing element of the apparatus. Other modules are implemented similarly. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element described herein may be an integrated circuit having signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in the form of software.

For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others. For another example, when some of the above modules are implemented in the form of a processing element scheduler code, the processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor that can call program code. As another example, these modules may be integrated together, implemented in the form of a system-on-a-chip (SOC).

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a readable storage medium or transmitted from one readable storage medium to another readable storage medium, for example, the computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Fig. 12 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 12, the terminal device may include: the device comprises a processor 121, a memory 122, a communication interface 123 and a system bus 124, wherein the memory 122 and the communication interface 123 are connected with the processor 121 through the system bus 124 and complete mutual communication, the memory 122 is used for storing computer execution instructions, the communication interface 123 is used for communicating with other devices, and the processor 121 implements the implementation scheme of the method embodiment shown in fig. 1 to 10 when executing the computer execution instructions.

The system bus mentioned in fig. 12 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The system bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus. The communication interface is used for realizing communication between the database access device and other equipment (such as a client, a read-write library and a read-only library). The memory may comprise Random Access Memory (RAM) and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.

The processor may be a general-purpose processor, including a central processing unit CPU, a Network Processor (NP), and the like; but also a digital signal processor DSP, an application specific integrated circuit ASIC, a field programmable gate array FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components.

The present application further provides a computer-readable storage medium, which stores instructions that, when executed on a computer, cause the computer to perform the method according to the embodiments shown in fig. 1 to 10.

Illustratively, the embodiment of the present application further provides a chip for executing the instructions, where the chip is used to execute the method in the embodiments shown in fig. 1 to 10.

In the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship; in the formula, the character "/" indicates that the preceding and following related objects are in a relationship of "division". "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

It is to be understood that the various numerical references referred to in the embodiments of the present application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of the present application.

It should be understood that, in the embodiment of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiment of the present application.

Claims

1. A fingerprint identification method, comprising:

2. The method according to claim 1, characterized in that the acquisition time interval of the first fingerprint image and the second fingerprint image satisfies a preset time interval threshold.

3. The method according to claim 1 or 2, wherein said acquiring a first fingerprint image and a second fingerprint image acquired at different times comprises:

4. The method according to claim 1 or 2, wherein said acquiring a first fingerprint image and a second fingerprint image acquired at different times comprises:

acquiring the first fingerprint image when a user presses a fingerprint sensor;

5. The method according to claim 1 or 2, wherein said acquiring a first fingerprint image and a second fingerprint image acquired at different times comprises:

calculating a pressure value corresponding to each frame of fingerprint image;

6. The method according to any one of claims 1-5, wherein determining a pressure value corresponding to a fingerprint image for any one of the first fingerprint image and the second fingerprint image comprises:

determining an effective calculated area of the fingerprint image;

7. The method of claim 6, wherein determining the effective computed area of the fingerprint image comprises:

determining an imaging area coefficient of the fingerprint image;

8. The method of claim 7, wherein determining the imaging area coefficient for the fingerprint image comprises:

9. The method according to claim 7, wherein the determining the actual imaging area in the fingerprint image according to the gray scale value of each pixel in the fingerprint image and a preset gray scale threshold value comprises:

10. The method of any of claims 1-9, wherein the pressure rating comprises: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

11. The method of claim 10, further comprising:

determining the pressure grade of the first pressure value;

12. The method of claim 10, further comprising:

13. The method according to claim 11 or 12, wherein for any one of the first fingerprint image and the second fingerprint image, determining whether a fingerprint image was obtained by capturing an authentic fingerprint comprises:

14. A fingerprint recognition device, comprising: the device comprises an acquisition module, a processing module and a determination module;

15. The apparatus of claim 14, wherein the acquisition time interval of the first fingerprint image and the second fingerprint image satisfies a preset time interval threshold.

16. The device according to claim 14 or 15, wherein the obtaining module is configured to obtain multiple frames of fingerprint images of a user pressing the fingerprint sensor at a single time, each frame of fingerprint image carries a respective obtaining time and a respective obtaining pressure value, and obtain the first fingerprint image and the second fingerprint image from the multiple frames of fingerprint images based on the obtaining time and the respective obtaining pressure value carried by each frame of fingerprint image.

17. The apparatus according to claim 14 or 15, wherein the acquiring module is configured to acquire the first fingerprint image when a user presses a fingerprint sensor, calculate a first pressure value corresponding to the first fingerprint image, determine a pressure level to which the first pressure value belongs, issue a pressing indication based on the pressure level to which the first pressure value belongs, the pressing indication being configured to instruct the user to press the fingerprint sensor with a pressure intensity different from the pressure level to which the first pressure value belongs, and acquire the second fingerprint image when the user presses the fingerprint sensor based on the pressing indication.

18. The apparatus according to claim 14 or 15, wherein the obtaining module is specifically configured to collect multiple frames of fingerprint images of a user pressing the fingerprint sensor once, each frame of fingerprint image carries a respective collecting time, calculate a pressure value corresponding to each frame of fingerprint image, and obtain the first fingerprint image and the second fingerprint image, of which the pressure values respectively belong to different pressure levels, from the multiple frames of fingerprint images based on the pressure value corresponding to each frame of fingerprint image.

19. The apparatus according to any one of claims 14 to 18, wherein the processing module is specifically configured to determine, for any one of the first fingerprint image and the second fingerprint image, an effective calculation area of the fingerprint image, and determine a pressure value corresponding to the fingerprint image according to a preset correspondence relationship between the area and the pressure value.

20. The apparatus according to claim 19, wherein the processing module is specifically configured to determine an imaging area coefficient of the fingerprint image, determine an actual imaging area in the fingerprint image according to a gray-level value of each pixel in the fingerprint image and a preset gray-level threshold, and determine an effective calculated area of the fingerprint image according to the imaging area coefficient and the actual imaging area.

21. The apparatus according to claim 20, wherein the processing module is specifically configured to count a number of imaging pixels in the fingerprint image, where the imaging pixels are pixels with gray values that are not white, and determine the imaging area coefficient of the fingerprint image according to the number of imaging pixels in the fingerprint image and a theoretical number of pixels included in the fingerprint image.

22. The apparatus according to claim 20, wherein the processing module is specifically configured to determine effective pixels in the fingerprint image, where the effective pixels are pixels with a gray value smaller than a preset gray threshold, and determine an actual imaging area in the fingerprint image according to the number of the effective pixels in the fingerprint image.

23. The apparatus of any one of claims 14-22, wherein the pressure rating comprises: a first pressure level less than a first pressure threshold and a second pressure level greater than a second pressure threshold, the second pressure threshold being greater than the first pressure threshold.

24. The apparatus of claim 23, wherein the processing module is further configured to determine a pressure level to which the first pressure value belongs, determine whether the first fingerprint image was obtained by capturing an authentic fingerprint when the first pressure value belongs to the first pressure level, determine whether the second pressure value belongs to a second pressure level when the first fingerprint image was obtained by capturing an authentic fingerprint, and determine whether the second fingerprint image was obtained by capturing an authentic fingerprint when the second pressure value belongs to the second pressure level.

25. The apparatus of claim 23, wherein the processing module is further configured to determine a pressure class to which the first pressure value belongs and a pressure class to which the second pressure value belongs, determine whether the first pressure value and the second pressure value belong to different pressure classes, and determine whether the first fingerprint image and the second fingerprint image are obtained by collecting a real fingerprint when the first pressure value and the second pressure value belong to different pressure classes.

26. The apparatus according to claim 24 or 25, wherein the processing module is further specifically configured to, for any one of the first fingerprint image and the second fingerprint image, input the fingerprint image into a fingerprint identification model, and determine whether the fingerprint image is obtained by collecting an authentic fingerprint, where the fingerprint identification model is a pre-trained model for identifying whether the input fingerprint image is obtained by collecting an authentic fingerprint.

27. A terminal device comprising a processor, a memory and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the method according to any of the preceding claims 1-13 when executing the program.

28. A storage medium having stored therein instructions which, when run on a computer, cause the computer to perform the method of any one of claims 1-13.