CN111274906A - Fingerprint anti-counterfeiting method and device - Google Patents

Abstract

The invention discloses a fingerprint anti-counterfeiting method and device. The method includes: forming an anti-counterfeiting detection light spot with a preset pattern, and using the anti-counterfeiting detection light spot to illuminate a target object, the anti-counterfeiting detection light spot includes a light-emitting area and a non-light-emitting area area, the detection light emitted by the light-emitting area is at least partially reflected by the target object; an anti-counterfeiting image is formed by receiving the light reflected by the target object and passing through the anti-counterfeiting detection light spot, wherein the anti-counterfeiting image includes mutually separated at least one first fingerprint feature and at least one second fingerprint feature, wherein the first fingerprint feature and the second fingerprint feature are images of fingerprint information reflected from the same light-emitting area mapped to the photosensitive unit; processing the first fingerprint The target object is identified as a three-dimensional finger or a two-dimensional finger based on the information of the feature and/or the second fingerprint feature. The invention can accurately identify the 2D fake fingerprint, thereby improving the security of the fingerprint identification device.

Description

Fingerprint anti-counterfeiting method and device

technical field

The invention relates to the technical field of optical fingerprint identification, in particular to a fingerprint anti-counterfeiting method and device.

Background technique

With the rapid development of communication technologies, users' demands for mobile terminals are increasing, and at the same time, the requirements for the use experience of mobile terminals are also getting higher and higher. In order to better meet the needs of users, fingerprint identification, as a relatively mature biometric identification technology, has been widely used in mobile terminals. Among them, the core part of the mobile terminal to realize fingerprint recognition is the optical fingerprint sensor.

As shown in FIG. 1, a general optical fingerprint sensor includes: a sensor pixel array, a lens, a light shielding layer, an OLED (Organic Light-Emitting Diode) screen and a transparent layer. When in use, the front of the OLED screen emits detection light, the detection light is reflected by the finger pressed on the screen, and concentrated into the sensor pixel array under the lens through the OLED screen. After the sensor pixel array receives the detection light, it can obtain the fingerprint indicating the fingerprint. Optical image. Due to the difference in light intensity reflected by the peaks and valleys of fingerprints, clear fingerprint texture pictures can be taken. The fingerprint texture image is a two-dimensional grayscale image.

However, the applicant found that: since the fingerprint texture picture corresponding to the fingerprint signal carried by the finger reflected light is a grayscale image, it can only reflect the plane contrast, so it is easy to be attacked by 2D (two-dimensional plane) fake fingerprints, resulting in the The device security of an optical fingerprint sensor is insufficient.

SUMMARY OF THE INVENTION

Based on the aforementioned defects of the prior art, embodiments of the present invention provide a fingerprint anti-counterfeiting method and device, which can accurately identify 2D fake fingerprints, thereby improving the security of fingerprint identification equipment.

In order to achieve the above objects, the present invention provides the following technical solutions.

A fingerprint anti-counterfeiting method, comprising:

An anti-counterfeiting detection light spot with a preset pattern is formed, and the anti-counterfeiting detection light spot is used to illuminate the target object, the anti-counterfeiting detection light spot includes a light-emitting area and a non-light-emitting area, and the detection light emitted by the light-emitting area is at least partially blocked by the target object reflection;

Receiving the light reflected by the target object and passing through the anti-counterfeiting detection light spot to form an anti-counterfeiting image, wherein the anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature separated from each other, the first fingerprint The feature and the second fingerprint feature are images of the fingerprint information reflected from the same light-emitting area mapped to the photosensitive unit;

The information of the first fingerprint feature and/or the second fingerprint feature is processed to identify the target object as a three-dimensional finger or a two-dimensional finger.

In a preferred embodiment, the area of the non-light-emitting region is larger than that of the light-emitting region.

In a preferred embodiment, the area ratio of the light-emitting area and the non-light-emitting area in the anti-counterfeiting detection light spot pattern is greater than 1:19 and less than 1:1.

In a preferred embodiment, the anti-counterfeiting detection light spot is a light and dark striped light spot.

In a preferred embodiment, the width ratio of bright stripes to dark stripes in the striped light spot is 3:17.

In a preferred embodiment, the anti-counterfeiting detection light spot further includes any one of the following: a light and dark annular stripe light spot extending from the center to the periphery; or along the first direction and perpendicular to the first direction Light and dark grid light spots extending in the second direction; or, the light-emitting area is a plurality of discontinuous light-emitting parts formed on the non-light-emitting area.

In a preferred embodiment, the fingerprint anti-counterfeiting method further comprises: forming a fingerprint identification light spot to illuminate the target object to collect fingerprint information of the target object.

In a preferred embodiment, processing the information of the first fingerprint feature and/or the second fingerprint feature includes extracting the information corresponding to the two-dimensional finger and the three-dimensional finger, respectively, in the first fingerprint feature and/or the second fingerprint feature. Difference parameter.

In a preferred embodiment, the fingerprint anti-counterfeiting method further comprises: preprocessing the anti-counterfeiting image to obtain a transformed anti-counterfeiting image, and processing the first fingerprint feature and/or the first fingerprint feature and/or the first fingerprint in the transformed anti-counterfeiting image. The target object is identified as a three-dimensional finger or a two-dimensional finger based on the information of the two fingerprint features.

A fingerprint anti-counterfeiting device, the fingerprint anti-counterfeiting device includes: a detection light source, a control unit, an anti-counterfeiting detection light spot, an optical function unit and a photosensitive unit; wherein,

The anti-counterfeiting detection light spot is used as the detection light source to illuminate the target object;

The control unit controls the detection light source to form the anti-counterfeiting detection light spot with a preset pattern; when the light emitted by the detection light source to the target object is reflected back through the anti-counterfeiting detection light spot, the optical function unit is in the An anti-counterfeiting image is formed on the photosensitive unit;

The anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature separated from each other, and the first fingerprint feature and the second fingerprint feature are the fingerprint information reflected from the same location area of the target object and map to image of the photosensitive unit.

In a preferred embodiment, the fingerprint anti-counterfeiting device further comprises a fingerprint identification light spot, the fingerprint identification light spot is used to collect the fingerprint information of the target object, and the pattern of the anti-counterfeiting detection light spot is the same as that of the fingerprint identification light spot. Patterns are different.

In a preferred embodiment, the anti-counterfeiting detection light spot has a light-emitting area and a non-light-emitting area, and the area of the light-emitting area is smaller than that of the non-light-emitting area.

In a preferred embodiment, the anti-counterfeiting detection light spot is a light and dark stripe pattern, and the area of the stripes in the dark area is larger than the area of the stripes in the bright area.

In a preferred embodiment, the ratio of the dark area stripe area to the bright area stripe area is greater than 1:19 and less than 1:1.

In a preferred embodiment, the detection light source is a light source of an OLED screen.

In a preferred embodiment, the optical functional unit includes an optical lens assembly.

The technical scheme of the present invention has the following significant beneficial effects:

Embodiments of the present invention provide a fingerprint anti-counterfeiting method and device, which collect an image of a target object by using an anti-counterfeiting detection light spot with a preset pattern, and the preset pattern of the anti-counterfeiting detection light spot makes at least one of the anti-counterfeiting detection light spots identical The target fingerprint information illuminated by the light-emitting area generates a separate first fingerprint feature and a second fingerprint feature; using the first fingerprint feature and/or the second fingerprint feature corresponds to the target object being a two-dimensional finger and a three-dimensional finger exists The difference is that the target object is distinguished as a three-dimensional finger or a two-dimensional finger, so that the security of the fingerprint identification device can be improved.

With reference to the following description and drawings, specific embodiments of the invention are disclosed in detail, indicating the manner in which the principles of the invention may be employed. It should be understood that embodiments of the present invention are not thereby limited in scope. Embodiments of the invention include many changes, modifications and equivalents within the spirit and scope of the appended claims. Features described and/or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, in combination with, or instead of features in other embodiments .

Description of drawings

The drawings described herein are for explanatory purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes and proportions of the components in the figures are only schematic and are used to help the understanding of the present invention, and do not specifically limit the shapes and proportions of the components of the present invention. Under the teachings of the present invention, those skilled in the art can select various possible shapes and proportions according to specific conditions to implement the present invention. In the attached image:

1 is a schematic structural diagram of an OLED under-screen module in the prior art;

2 is a flowchart of steps of a fingerprint anti-counterfeiting method provided in an embodiment of the present invention;

3 is a schematic diagram of a first anti-counterfeiting detection light spot provided in an embodiment of the present invention;

Fig. 4 is an anti-counterfeiting image formed by a 3D real finger;

Fig. 5 is an anti-counterfeiting image formed by a 2D fake fingerprint;

Fig. 6 is a denoising enhanced image formed after the anti-counterfeiting image formed by a 3D real finger in Fig. 4 is deducted from the reference;

Fig. 7 is a denoising enhanced image formed after the anti-counterfeiting image formed by a 2D fake fingerprint in Fig. 5 is deducted from the reference;

8 is a schematic block diagram of a fingerprint anti-counterfeiting method provided in an embodiment of the present invention;

9 is a schematic diagram of a second type of anti-counterfeiting detection light spot provided in an embodiment of the present invention;

10 is a schematic diagram of a third anti-counterfeiting detection light spot provided in an embodiment of the present invention;

11 is a schematic diagram of a fourth anti-counterfeiting detection light spot provided in an embodiment of the present invention;

FIG. 12 is a block diagram of a fingerprint anti-counterfeiting device provided in an embodiment of the present invention.

Description of reference numbers:

1. Transparent layer;

2. OLED screen; B. Anti-counterfeiting detection light spot;

3, shading layer;

4. Lens;

5. Pixels;

20. Detect light source;

30. Optical functional unit;

50. Photosensitive unit;

6. Control unit;

100. Fingerprint chip module.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The embodiments of the present invention provide a fingerprint anti-counterfeiting method and device, which can accurately distinguish or judge whether it is a two-dimensional fingerprint or a three-dimensional fingerprint, avoid using two-dimensional fingerprint information instead of three-dimensional fingerprint for fingerprint identification or unlocking, and improve the security of fingerprint identification. sex.

Here, the fingerprint anti-counterfeiting method is applied to a mobile phone communication device as an example, but the fingerprint identification device is not limited to be applied to other electronic devices, such as fingerprint locks, or other electronic devices that need to be identified and unlocked by fingerprints.

Among the commonly used mobile communication devices, the display screen of the mobile phone is more commonly used OLED screen. According to the introduction of the OLED screen in the prior art, the OLED screen can be understood as a self-luminous display device. Therefore, in the introduction of this embodiment, the OLED screen can be used as a detection light source for fingerprint detection. For example, on the OLED screen of a mobile phone, the OLED pixel array in the fingerprint sensing area can emit light spots to illuminate the finger to collect the user's fingerprint. The shape of the conventional light spot used for collecting fingerprint images may be circular or other forms, which are referred to as fingerprint identification light spots hereinafter.

The fingerprint identification light spot can be a light spot of any preset pattern, or a full bright light spot, which is not limited here. The fingerprint identification light spot may include any one of the following: a solid color light spot with the same brightness in the predetermined area, and a gradient light spot with the brightness gradually becoming brighter from the center to the periphery in the predetermined area. Wherein, the size, shape, etc. of the predetermined area may be different according to the composition distribution of the hardware structure of the device, and the like. Wherein, when the fingerprint identification light spot is a gradient light spot that gradually becomes brighter from the center to the periphery, the brightness distribution of the collected fingerprint image can be uniform on the plane.

Using the anti-counterfeiting detection light spot can distinguish real fingers and 2D fake fingerprints, so that the fingerprint identification device applying the fingerprint anti-counterfeiting method has anti-counterfeiting function. The present application will be described in detail below with reference to the specific drawings and embodiments.

Referring to FIG. 2, an embodiment of the present application provides a fingerprint anti-counterfeiting method, and the fingerprint anti-counterfeiting method may include:

Step S10 : forming an anti-counterfeiting detection light spot with a preset pattern, and using the anti-counterfeiting detection light spot to illuminate the target object, the anti-counterfeiting detection light spot includes a light-emitting area and a non-light-emitting area, and the detection light emitted by the light-emitting area is at least partially Describe the target object reflection;

Step S12: Receiving the light reflected by the target object and passing through the anti-counterfeiting detection light spot to form an anti-counterfeiting image, wherein the anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature separated from each other, the The first fingerprint feature and the second fingerprint feature are images of the fingerprint information reflected from the same light-emitting area of the target object mapped to the photosensitive unit;

Step S14: Process the information of the first fingerprint feature and/or the second fingerprint feature to identify the target object as a three-dimensional finger or a two-dimensional finger.

In this embodiment, lighting the anti-counterfeiting detection light spot with the preset pattern can be realized after receiving a predetermined activation signal. Specifically, the predetermined start signal may vary according to specific application scenarios, which is not specifically limited in this application. For example, when the fingerprint anti-counterfeiting method is applied to an electronic device having a fingerprint identification area, the activation signal may be a signal generated by a user's finger touch or press.

When the start signal is received, the light spot can be lit. Specifically, the lighted light spot may include an anti-counterfeiting detection light spot for distinguishing a three-dimensional finger from a two-dimensional finger. In addition, the illuminated light spot may also include a fingerprint identification light spot for collecting fingerprint images. In this specific embodiment, the anti-counterfeiting detection light spot is different from the conventional fingerprint identification light spot: the anti-counterfeiting detection light spot is not used to collect the fingerprint information of the target object, but the target object is a two-dimensional finger or a three-dimensional finger. differentiate. Therefore, the anti-counterfeiting detection light spot is not used to detect the detailed fingerprint information of the target object, but to judge whether the target finger is a two-dimensional finger or a three-dimensional finger. In some electronic devices for fingerprint authentication, the light spot for collecting fingerprint information may include these two light spots, the fingerprint identification light spot and the anti-counterfeiting detection light spot.

Wherein, the anti-counterfeiting detection light spot is a light spot with a preset pattern. Specifically, the anti-counterfeiting detection light spot may include: a light-emitting area and a non-light-emitting area. The region where the light-emitting region and the non-light-emitting region are bounded and transitioned is a border region. Wherein, the preset pattern may be formed by cooperation of the light-emitting area and the non-light-emitting area in the light spot, and the boundary area is the boundary of the preset pattern. Certainly, the specific shape of the preset pattern can be adaptively designed according to the actual application, which is not limited in this application.

Wherein, the area of the light-emitting area in the anti-counterfeiting detection light spot is smaller than the area of the non-light-emitting area, so as to ensure that the generated anti-counterfeiting image can have an image with a clear boundary between light and dark, thereby generating the first fingerprint feature and the second fingerprint feature that are separated from each other. Fingerprint features.

In this embodiment, in the anti-counterfeiting detection light spot, the area ratio of the light-emitting area and the non-light-emitting area needs to be reasonably selected. In the embodiment of the anti-counterfeiting detection light spot for some preset patterns, if the area ratio of the two is too small, that is, the light-emitting area is too small relative to the area of the non-light-emitting area, for example, the area of the light-emitting area and the non-light-emitting area of the anti-counterfeiting detection light spot is less than 1 : 19, the light source is not enough; if the light-emitting area is too large relative to the area of the non-light-emitting area, the coincidence of the light-emitting area of the finger feature and the false-finger feature light-emitting area will affect the features on the separated first fingerprint feature and/or the second fingerprint feature parameters, resulting in weak differences between two-dimensional and three-dimensional target objects based on the feature parameters, and cannot be distinguished. Therefore, for the embodiments of the anti-counterfeiting detection light spots of these preset patterns, the area ratio of the light-emitting area and the non-light-emitting area of the anti-counterfeiting detection light spot can be set to be greater than 1:19 and less than 1:1.

In the embodiments provided in this application, the shape and area of the anti-counterfeiting detection light spot can be preferably set as required. Please refer to FIG. 3 , in some embodiments, the anti-counterfeiting detection light spot B is a light spot with alternating light and dark. In this embodiment, the light and dark striped light spot is mainly used as an example for detailed description, and the specific description of this embodiment can be adaptively referred to for the detection principles and technical effects of other anti-counterfeiting detection light spots.

As shown in FIG. 3 , the anti-counterfeiting detection light spot B may be a light and dark striped light spot extending along the first direction, including bright stripes and dark stripes. Compared with the anti-counterfeiting detection light spots of other patterns, the anti-counterfeiting detection light spot B of this pattern has better robustness due to the lower requirement for calibration between system positions. In the anti-counterfeiting retrieval light spot of this preset pattern, the ratio of the width of the bright stripes to the dark stripes can be 3:17.

In this embodiment, the anti-counterfeiting detection light spot B can be a one-dimensional light spot, for example, a line-to-light spot, as shown in FIG. 3 , on the one hand, it is beneficial to reduce the complexity of subsequent image and data processing, and on the other hand, it is also beneficial to ensure The accuracy and reliability of fingerprint anti-counterfeiting identification. In addition, the cost of forming the anti-counterfeiting detection light spot B is relatively low. The anti-counterfeiting detection light spot B has bright and dark striped light spots extending along the first direction. The bright stripes and dark stripes of the striped spot are parallel to each other. The ratio of the width of the bright stripes to the dark stripes is 3:17, so as to facilitate the formation of an anti-counterfeiting image capable of significantly identifying 2D fake fingerprints (ie, two-dimensional fake fingers).

In some specific electronic devices using fingerprint identification and/or anti-counterfeiting chips, the fingerprint identification light spot and the anti-counterfeiting detection light spot B can be lit by the same set of detection light sources. The detection light source may be a light source provided by a self-luminous OLED screen, or may be other detection light sources outside the screen. In the example in which the fingerprint identification light spot and the anti-counterfeiting detection light spot B are lit by the same set of detection light sources, the fingerprint identification light spot and the anti-counterfeiting detection light spot B can be lit at different times. range, i.e. two different patterns of light blobs that may be harder to detect by the human eye.

In the electronic equipment applied to fingerprint identification and anti-counterfeiting, it is necessary to use the fingerprint identification light spot to collect the fingerprint image. After the fingerprint image is collected, the collected fingerprint image can be subsequently compared with the stored fingerprint image. If the comparison is successful, it can be further determined whether the fingerprint is a 2D fake fingerprint.

In this embodiment, after the anti-counterfeiting detection light spot B is turned on, the detection light emitted by the light-emitting area is at least partially reflected by the target object, and is received by the photosensitive unit after passing through the anti-counterfeiting detection light spot B, forming an anti-counterfeiting unit in the sensory unit. image. Wherein, the target fingerprint information illuminated by at least one same light-emitting area in the false detection light spot B generates an anti-counterfeiting image. The anti-counterfeiting image includes a first fingerprint feature and a second fingerprint feature that are separated from each other. The first fingerprint feature and the second fingerprint feature are images of fingerprint information reflected from the same light-emitting area mapped to the photosensitive unit. Subsequently, the first fingerprint feature and/or the second fingerprint feature may be used to distinguish the target object as a three-dimensional finger or a two-dimensional finger by using the difference between the target object being a two-dimensional finger and a three-dimensional finger.

It should be noted here that the fingerprint information reflected by the same light-emitting area has a one-to-one correspondence with the first fingerprint feature and the second fingerprint feature separated in the anti-counterfeiting image. That is to say, the fingerprint information reflected by the same light-emitting area can be reflected by the separated first fingerprint feature and second fingerprint feature.

In one embodiment, the fingerprint identification light spot or the anti-counterfeiting detection light spot B can be lit by an OLED screen. The OLED screen includes a glass layer having opposing first and second surfaces. The distance between the first surface and the second surface is H. The first surface is provided with a detection area for contacting with the user's finger. Wherein, the detection area may be a local area on the OLED screen, and certainly may be the entire OLED screen.

In this embodiment, the predetermined pattern of the anti-counterfeiting detection light spot is the striped pattern with alternating light and dark as shown in FIG. 3 as an example for description.

Specifically, corresponding to the same luminous bright stripe area, strip-shaped fingerprint information of large-angle reflection and small-angle reflection will be formed in the anti-counterfeiting image collected by the image collector. Please refer to the corresponding 3D finger and 2D finger images in the anti-counterfeiting images collected on Figures 4 and 5. In the anti-counterfeiting images shown in Fig. 4 and Fig. 5, the target object illuminated by the same bright stripe area will generate the first fingerprint feature and the second fingerprint feature separated from each other in Fig. 4 and Fig. 5, for example, Fig. 4 The middle stripe ① is the second fingerprint feature, and the stripe ② is the first fingerprint feature; in FIG. 5 , the stripe ① is the second fingerprint feature, and the stripe ② is the first fingerprint feature. The fingerprint information in stripe 1 and stripe 2 comes from the same bright stripe detection light irradiating the target object, and the detection light reflected by the target object enters the image collector through the anti-counterfeiting detection spot.

The characteristics of each column of spots in Figures 4 and 5 are different. Assuming that the fingerprint features ②, ④, and ⑥ in FIG. 4 are the first fingerprint features corresponding to the bright stripes, the feature parameter of the first fingerprint feature—the valley ridge has a large contrast between light and dark, and can be distinguished by the naked eye. The first fingerprint features ②, ④, ⑥ in FIG. 5 corresponding to FIG. 4 also have fingerprint information, but the feature parameter of the first fingerprint feature—the valley ridge light and dark contrast is weak and cannot be distinguished by the naked eye. Since FIG. 4 and FIG. 5 respectively correspond to a three-dimensional finger and a two-dimensional finger, in this embodiment, the difference in the characteristic parameter of the contrast between valley and ridge in the first fingerprint feature can be directly used to distinguish a two-dimensional finger from a three-dimensional finger .

Of course, in this anti-counterfeiting image, in order to distinguish whether the target object is a two-dimensional finger or a three-dimensional finger, the anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature corresponding to the same light-emitting area and separated from each other. As in the above embodiments, there are actually multiple light-emitting regions, so in fact, each light-emitting region has its corresponding first fingerprint feature and second fingerprint feature. When there are multiple first fingerprint features and second fingerprint features in the anti-counterfeiting image, more comparison and reference data are provided for anti-counterfeiting judgment, which can further improve the accuracy of anti-counterfeiting judgment. Here, the scope of the present application is not limited to that the anti-counterfeiting image must contain a plurality of mutually separated first fingerprint features and second fingerprint features corresponding to a plurality of light-emitting regions.

In the specific embodiment exemplified above, the anti-counterfeiting image obtained without near-algorithm processing can use the difference in the characteristic parameter of the contrast of valleys and ridges in the first fingerprint feature to determine whether the target object is a two-dimensional finger or a three-dimensional finger. Specifically, a threshold can be set for this characteristic parameter. When the characteristic parameter is less than a certain value, the target object is determined to be a two-dimensional finger; when the characteristic parameter is greater than a certain threshold, the target object is determined to be a three-dimensional finger.

In other embodiments, the image obtained by the image collector can be processed by algorithm to make it more optimized, so as to improve the accuracy of judgment.

Specifically, a set of reference images can be collected and stored in advance, and then it can be further judged based on the reference images to identify whether it is a 2D fake fingerprint. Specifically, the reference image may be a light spot image obtained by using the anti-counterfeiting detection light spot B to perform multiple real finger pressings. The main purpose of using this benchmark map is to deduct differences in dynamic background, ambient light, and shading.

The collected anti-counterfeiting image can be deducted from a reference by using a preset reference map, and the anti-counterfeiting image can be converted into a denoising enhanced image. According to the denoised enhanced image, it is judged whether the collected anti-counterfeiting image is a 2D fake fingerprint.

Specifically, by deducting the reference image, the group of light spots of the 3D real finger can be distinguished. For details, please refer to Figure 6 and Figure 7. For example, the areas ① and ⑤ in Fig. 6 show the second fingerprint features corresponding to different light-emitting stripe regions. The second fingerprint feature is a fingerprint feature formed by a small-angle reflection signal. The difference in the grayscale of the valley and ridge is small. The fingerprint features disappear; while the regions ②, ④, and ⑥ correspond to the first fingerprint features of ②, ④, and ⑥ shown in Figure 4, which come from the fingerprint features formed by large-angle reflection signals. The fingerprint features are still retained after the image.

By deducting the reference image, a group of light spots of the 2D fake fingerprint all present fingerprint features. As shown in Figure 7, the first fingerprint feature and the second fingerprint feature are almost indistinguishable from each other and before.

Therefore, the fingerprint anti-counterfeiting method provided in this embodiment can also judge whether the target object is a two-dimensional finger or a three-dimensional finger according to the difference of the second fingerprint feature in the collected anti-counterfeiting image according to the denoising enhanced image. Specifically, it can be identified whether there is local distortion in the second fingerprint feature, and if there is no local distortion, it is determined as a two-dimensional fake fingerprint. Or, it can be judged according to the difference between the brightness and darkness of the valley and ridge in the identified first fingerprint feature.

In the two embodiments exemplified above, the anti-counterfeiting image has formed a first fingerprint feature (eg, regions ②, ④, ⑥) and a second fingerprint feature (eg, regions ①, ⑤). Among them, in the original obtained image, the first fingerprint feature can distinguish between a real 3D finger and a fake 2D fake fingerprint due to the principle explained above. In addition, in another embodiment, after the anti-counterfeiting image is processed by the algorithm, the second fingerprint feature can also extract certain anti-counterfeiting features. According to the imaging principle, the light-dark transition area of the anti-counterfeiting detection light spot B is very sensitive to the height information of the reflective surface. , mainly as follows: There is a height difference between the valleys and ridges of the real 3D finger surface texture, and the fingerprint pattern formed at the edge of the light spot will be distorted; therefore, the second fingerprint features (such as areas ①, ⑤) can be identified by algorithm using an algorithm. feature.

In other embodiments of the anti-counterfeiting method of the present application, due to the different algorithms of the anti-counterfeiting image, the difference between the first fingerprint feature and/or the second fingerprint feature in the anti-counterfeiting pattern will be different. The two ways to extract the first fingerprint feature or the second fingerprint feature respectively correspond to the difference between the two-dimensional finger and the three-dimensional finger, but are not limited thereto.

In a practical application scenario, based on the fingerprint anti-counterfeiting method provided by the present application, a preliminary fingerprint information identification can be performed on a fingerprint image by using a fingerprint identification light spot. If it is clearly believed that the fingerprint information of the target object cannot be matched, the anti-counterfeiting detection light spot B does not need to be lit, saving time. If the fingerprint recognition light spot matches the fingerprint information obtained by the target object successfully, the anti-counterfeiting detection light spot B can be lit to determine whether the finger is 2D finger information or 3D finger information, so as to avoid the successful use of the 2D fake finger of the matcher's fingerprint. Unlock security devices to improve the security of fingerprint unlocking of electronic devices.

An embodiment in which the fingerprint anti-counterfeiting method is specifically applied to an electronic device to realize anti-counterfeiting will be described with reference to FIG. 8 . Based on the flowchart shown in FIG. 8 , the fingerprint anti-counterfeiting of the electronic device may include the following steps:

Step S11: lighting the fingerprint identification light spot for collecting the fingerprint image after receiving the predetermined start signal;

Step S12: collecting a fingerprint image after the fingerprint identification light spot is bright;

Step S13: Compare the collected fingerprint image with the stored fingerprint image;

Step S14: if the comparison is successful, light up the anti-counterfeiting detection light spot B used to collect the anti-counterfeiting image, the anti-counterfeiting detection light spot B includes: a light-emitting area and a non-light-emitting area, and the area of the light-emitting area is smaller than the area of the non-light-emitting area ;

Step S15: After the anti-counterfeiting detection light spot B is lit, an anti-counterfeiting image is collected, and the anti-counterfeiting image 6 includes: separated first fingerprint features and second fingerprint features;

Step S16: using the preset reference map, deducting the reference of the collected anti-counterfeiting image, and converting it into a denoising enhanced image;

Step S17: Determine whether the collected anti-counterfeiting image is a 2D fake fingerprint according to the denoised enhanced image.

In this embodiment, for each specific step in the above-mentioned steps, reference may be made to the specific description of the above-mentioned embodiment, which will not be repeated in this application.

On the whole, using the fingerprint anti-counterfeiting method provided by the embodiment of the present application, by lighting a new light spot with alternating light and dark, the anti-counterfeiting detection light spot can be collected by using the light spot. The bright target fingerprint information generates an anti-counterfeiting image, and the anti-counterfeiting image includes a first fingerprint feature and a second fingerprint feature separated from each other; using the first fingerprint feature and/or the second fingerprint feature corresponding to the target object is a two-dimensional The difference between a finger and a three-dimensional finger can distinguish the target object as a three-dimensional finger or a two-dimensional fingerprint, thereby improving the security of the fingerprint identification device.

In some other embodiments, the anti-counterfeiting detection light spot B may further include any one of the following: a light and dark annular striped light spot extending from the center to the periphery, along the first direction and with the first Light and dark grid light spots extending in a second direction perpendicular to the direction; or, the light-emitting area is a plurality of discontinuous light-emitting parts formed on the non-light-emitting area.

As shown in FIG. 9 , the anti-counterfeiting detection light spot B may be a light and dark annular striped light spot extending from the center to the periphery. When the anti-counterfeiting detection light spot B is the above-mentioned annular striped light spot, it corresponds to a two-dimensional light spot, which is beneficial to identify some special fingerprints that may not be well identified by the one-dimensional light spot. When the fingerprint to be recognized is a one-dimensional fingerprint as a whole and is parallel to the anti-counterfeiting detection light spot B, a two-dimensional light spot is required for identification.

Specifically, the annular striped light spot may be in a ring shape. Due to the brightness attenuation of the lens, the brightness attenuation of the lens may overlap with the attenuation of the light and shade of the light spot, causing interference. In order to avoid the above interference, the center of the annular striped light spot is aligned with the center of the module lens 4 .

As shown in FIG. 10 , the anti-counterfeiting detection light spot B may be a light and dark grid light spot extending along a first direction and a second direction perpendicular to the first direction.

As shown in FIG. 11 , the anti-counterfeiting detection light spot B may be a plurality of discontinuous light-emitting parts formed on the non-light-emitting area. Specifically, the light-emitting portion may be in the shape of a "cross" as shown in FIG. 6 . Of course, the light-emitting portion may also have other shapes, which are not specifically limited herein.

Based on the fingerprint anti-counterfeiting method provided by the above embodiments, the present application further provides a fingerprint anti-counterfeiting device.

For a schematic diagram of a specific embodiment of the fingerprint anti-counterfeiting device in this application, please refer to FIG. 12 . The fingerprint anti-counterfeiting device may include: a detection light source 20 , a control unit 6 , an anti-counterfeiting detection light spot B, an optical function unit 30 and a photosensitive unit 50 . In a specific embodiment, the detection light source may be a self-luminous screen such as an OLED screen as the detection light source 20 . The OLED screen can be used to form a fingerprint identification light spot and an anti-counterfeiting detection light spot B. For example, the anti-counterfeiting detection light spot B is formed in a local area of the OLED screen. The local area may be a fingerprint detection area. The control unit 6 can control the fingerprint identification light spot and the anti-counterfeiting detection light spot B to be displayed on the OLED screen. For the same OLED screen, the control unit 6 can control the lighting sequence of the fingerprint identification light spot and the anti-counterfeiting detection light spot B according to a predetermined sequence. Of course, in other embodiments, the detection light source is not limited to being an OLED screen, but other detection light sources separately provided for the fingerprint anti-counterfeiting device, which will not be listed in detail here.

The control unit 6 controls the detection light source 20 to form the anti-counterfeiting detection light spot B. As shown in an embodiment shown in FIG. 12 , the control unit 6 may include: a sensor control unit and an electronic device control center. The detection light source can be controlled by a sensor control unit, or can be controlled by an electronic device control center. The fingerprint anti-counterfeiting device may be provided with a fingerprint identification area. When the fingerprint identification area receives a predetermined signal of the target object, for example, a user's finger pressing signal, touch signal and other signals, the signal can be transmitted to the control unit 6 . After the control unit 6 receives the signal, it can control the detection light source 20 to form an anti-counterfeiting detection light spot B. In this embodiment, the self-luminous display screen can be directly used as the detection light source 20 .

The light emitted by the anti-counterfeiting detection light spot B to the target object is reflected back through the anti-counterfeiting detection light spot B and the optical function unit 30 to form an anti-counterfeiting image on the photosensitive unit 50 . Wherein, the anti-counterfeiting image obtained by the anti-counterfeiting detection light spot B includes at least one first fingerprint feature and at least one second fingerprint feature separated by the fingerprint region of the target object illuminated by the same light-emitting area of the anti-counterfeiting detection light spot B. Subsequently, the anti-counterfeiting image of the photosensitive unit 50 can be transmitted to the control unit 6, and the control unit 6 determines whether the target object is a three-dimensional real finger or a two-dimensional fake fingerprint. Although in this embodiment, the optical function unit 30 is disposed directly above the photosensitive unit 50, in other embodiments, due to the difference in the optical path of the reflected fingerprint signal, the optical function unit is not necessarily located completely directly above or slightly above the photosensitive unit 50. A certain position offset is also possible.

Wherein, in this embodiment, the optical function unit 30 may include an optical lens assembly. Other focusing elements under the optical lens, such as microlenses or other optical elements, may also be included. The optical functional unit 30 may be a microlens structure and/or a collimation structure, so as to image the fingerprint signal passing through the anti-counterfeiting detection light spot in the photosensitive unit 50 .

Specifically, the control unit 6 can store the control logic of the fingerprint anti-counterfeiting method, so that the electronic device that should recognize the fingerprint sensor can perform the steps in the fingerprint anti-counterfeiting method. The specific identification process is not repeated here. The fingerprint identification device may specifically be an electronic device with fingerprint identification requirements, such as a mobile phone, a tablet, a computer, and the like. The control unit 6 may include an electronic device control center and a sensor control unit. Wherein, the optical function unit 30 , the photosensitive unit 50 and the sensor control unit may be integrated in the fingerprint chip module 100 .

In addition, the fingerprint anti-counterfeiting device may further include a fingerprint identification light spot. The fingerprint identification spot is used to collect more accurate fingerprint information of the target object, and its function is different from the anti-counterfeiting detection spot. Generally speaking, the pattern of the anti-counterfeiting detection light spot B is different from the pattern of the fingerprint identification light spot. The pattern of the anti-counterfeiting detection light spot is mainly used to distinguish whether the fingerprint of the target object is two-dimensional fingerprint information or three-dimensional fingerprint information.

On the whole, the fingerprint anti-counterfeiting device can achieve the technical effects that the above-mentioned fingerprint anti-counterfeiting method can achieve. For specific settings and identification principles, please refer to the specific description of the above-mentioned fingerprint anti-counterfeiting method, which will not be repeated in this application.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of" describing a combination shall include the identified element, ingredient, component or step as well as other elements, components, components or steps that do not materially affect the essential novel characteristics of the combination. Use of the terms "comprising" or "comprising" to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments consisting essentially of those elements, ingredients, components or steps. By using the term "may" herein, it is intended to indicate that "may" include any described attributes that are optional. A plurality of elements, components, components or steps can be provided by a single integrated element, component, component or step. Alternatively, a single integrated element, component, component or step may be divided into separate multiple elements, components, components or steps. The disclosure of "a" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments may be referred to each other. The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

Claims (16)

1. a fingerprint anti-counterfeiting method, is characterized in that, comprises: An anti-counterfeiting detection light spot with a preset pattern is formed, and the anti-counterfeiting detection light spot is used to illuminate the target object, the anti-counterfeiting detection light spot includes a light-emitting area and a non-light-emitting area, and the detection light emitted by the light-emitting area is at least partially blocked by the target object reflection; Receiving the light reflected by the target object and passing through the anti-counterfeiting detection light spot to form an anti-counterfeiting image, wherein the anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature separated from each other, the first fingerprint The feature and the second fingerprint feature are images of the fingerprint information reflected from the same light-emitting area mapped to the photosensitive unit; The information of the first fingerprint feature and/or the second fingerprint feature is processed to identify the target object as a three-dimensional finger or a two-dimensional finger. 2 . The fingerprint anti-counterfeiting method according to claim 1 , wherein the area of the non-light-emitting region is larger than that of the light-emitting region. 3 . 3 . The fingerprint anti-counterfeiting method according to claim 2 , wherein the area ratio of the light-emitting area and the non-light-emitting area in the pattern of the anti-counterfeiting detection light spot is greater than 1:19 and less than 1:1. 4 . 4 . The fingerprint anti-counterfeiting method according to claim 2 , wherein the anti-counterfeiting detection light spot is a light and dark striped light spot. 5 . 5 . The fingerprint anti-counterfeiting method according to claim 4 , wherein the width ratio of bright stripes to dark stripes in the striped light spot is 3:17. 6 . 6. The fingerprint anti-counterfeiting method according to claim 2, wherein the anti-counterfeiting detection light spot further comprises any one of the following: A light and dark annular striped light spot extending from the center to the periphery; or a light and dark grid light spot extending along a first direction and a second direction perpendicular to the first direction; or, the light-emitting area is in the A plurality of discontinuous light-emitting parts are formed on the non-light-emitting region. 7 . The fingerprint anti-counterfeiting method according to claim 1 , further comprising: forming a fingerprint identification light spot to illuminate the target object to collect fingerprint information of the target object. 8 . 8. The fingerprint anti-counterfeiting method according to claim 1, wherein processing the information of the first fingerprint feature and/or the second fingerprint feature comprises extracting the first fingerprint feature and/or the second fingerprint feature respectively. The difference parameters corresponding to 2D fingers and 3D fingers. 9 . The fingerprint anti-counterfeiting method according to claim 1 , wherein the fingerprint anti-counterfeiting method further comprises: preprocessing the anti-counterfeiting image to obtain a transformed anti-counterfeiting image, and processing the transformed anti-counterfeiting image. 10 . The target object is identified as a three-dimensional finger or a two-dimensional finger based on the information of the first fingerprint feature and/or the second fingerprint feature. 10. A fingerprint anti-counterfeiting device, characterized in that the fingerprint anti-counterfeiting device comprises: a detection light source, a control unit, an anti-counterfeiting detection light spot, an optical function unit and a photosensitive unit; wherein, The anti-counterfeiting detection light spot is used as the detection light source to illuminate the target object; The control unit controls the detection light source to form the anti-counterfeiting detection light spot with a preset pattern; when the light emitted by the detection light source to the target object is reflected back through the anti-counterfeiting detection light spot, the optical function unit is in the An anti-counterfeiting image is formed on the photosensitive unit; The anti-counterfeiting image includes at least one first fingerprint feature and at least one second fingerprint feature separated from each other, and the first fingerprint feature and the second fingerprint feature are the fingerprint information reflected from the same location area of the target object and map to The image of the photosensitive unit. 11 . The fingerprint anti-counterfeiting device according to claim 10 , further comprising a fingerprint identification light spot, the fingerprint identification light spot is used to collect the fingerprint information of the target object, and the pattern of the anti-counterfeiting detection light spot is related to the fingerprint. 12 . Identify the patterns of the light spots are different. 12 . The fingerprint anti-counterfeiting device according to claim 10 , wherein the anti-counterfeiting detection light spot has a light-emitting area and a non-light-emitting area, and the area of the light-emitting area is smaller than the non-light-emitting area. 13 . 13 . The fingerprint anti-counterfeiting device according to claim 12 , wherein the anti-counterfeiting detection light spot is a light and dark stripe pattern, and the area of the stripe in the dark area is larger than the area of the stripe in the bright area. 14 . 14 . The fingerprint anti-counterfeiting device according to claim 13 , wherein the ratio of the dark area stripe area to the bright area stripe area is greater than 1:19 and less than 1:1. 15 . 15. The fingerprint anti-counterfeiting device according to claim 10, wherein the detection light source is a light source of an OLED screen. 16. The fingerprint anti-counterfeiting device according to claim 11, wherein the optical function unit comprises an optical lens assembly.

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