CN113139414B - Optical fingerprint recognition and anti-counterfeiting method and system - Google Patents
Optical fingerprint recognition and anti-counterfeiting method and system Download PDFInfo
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- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
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- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
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Abstract
本发明公开了一种光学指纹识别和防伪方法及系统，该方法包括：形成指纹识别光斑，形成具有预设图案的防伪检测光斑，提供感光单元，分别接收目标对象在指纹识别光斑照射和在防伪检测光斑照射下的所携带的指纹信息，感光单元所接收的目标对象在防伪检测光斑照射下所携带的指纹信息而形成指纹防伪图像；依据指纹防伪图像判断目标对象为二维手指或者三维手指；防伪检测光斑的预设图案包括发光强度相异的第一检测区和第二检测区；提取指纹防伪图像中二维手指和三维手指对应的差异化特征参数而判断目标对象为二维手指或者三维手指。本发明能够准确识别出2D假指纹，从而提高指纹识别设备的安全性。
The present invention discloses an optical fingerprint recognition and anti-counterfeiting method and system, the method comprising: forming a fingerprint recognition light spot, forming an anti-counterfeiting detection light spot with a preset pattern, providing a photosensitive unit, receiving fingerprint information carried by a target object under the irradiation of the fingerprint recognition light spot and the anti-counterfeiting detection light spot respectively, the fingerprint information carried by the target object under the irradiation of the anti-counterfeiting detection light spot received by the photosensitive unit forms a fingerprint anti-counterfeiting image; judging the target object as a two-dimensional finger or a three-dimensional finger according to the fingerprint anti-counterfeiting image; the preset pattern of the anti-counterfeiting detection light spot includes a first detection area and a second detection area with different luminous intensities; extracting the differential feature parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image to judge the target object as a two-dimensional finger or a three-dimensional finger. The present invention can accurately identify 2D fake fingerprints, thereby improving the security of fingerprint recognition equipment.
Description
Technical Field
The invention relates to the field of optical fingerprint identification, in particular to an optical fingerprint identification and anti-counterfeiting method and system.
Background
With the rapid development of communication technology, users have increasingly demanded mobile terminals, and meanwhile, the demands on the use experience of the mobile terminals have also become higher. In order to better meet the use demands of users, fingerprint identification is used as a mature biological identification technology and is widely applied to mobile terminals. The core part of the mobile terminal for realizing fingerprint identification is an optical fingerprint sensor.
As shown in fig. 1, a general optical fingerprint sensor includes a sensor pixel array, a lens 4, a Light shielding layer 3, an OLED (Organic Light-Emitting Diode) screen, and a transparent layer 1. When the fingerprint sensor is used, the front surface of the OLED screen 2 emits detection light, the detection light is reflected by a finger pressed on the screen, the detection light is converged into a sensor pixel array below the lens 4 through the OLED screen 2, and after receiving the detection light, the sensor pixel array can acquire an optical image representing the fingerprint. Because the intensity of the light reflected by the wave crests and the wave troughs of the fingerprints is different, clear fingerprint texture pictures can be shot. The fingerprint texture picture is a two-dimensional gray scale picture.
However, the applicant found that since the fingerprint texture picture corresponding to the fingerprint signal carried by the reflected light of the finger is a gray scale picture, which can only reflect the plane contrast, the fingerprint texture picture is easily attacked by 2D (two-dimensional plane) fake fingerprints, so that the safety of the device of the optical fingerprint sensor is insufficient.
Disclosure of Invention
Based on the foregoing drawbacks of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide an optical fingerprint identification and anti-counterfeit method and system, which can accurately identify 2D fake fingerprints, so as to improve the security of fingerprint identification equipment.
The specific technical scheme of the embodiment of the invention is as follows:
An optical fingerprint identification and anti-counterfeiting method, comprising:
forming a fingerprint identification light spot, and irradiating a target object by using the fingerprint identification light spot;
forming an anti-counterfeiting detection light spot with a preset pattern, and irradiating a target object by using the anti-counterfeiting detection light spot;
Providing a photosensitive unit, and respectively receiving the carried fingerprint information of the target object under the irradiation of the fingerprint identification light spot and the irradiation of the anti-counterfeiting detection light spot, wherein the fingerprint information carried by the target object under the irradiation of the anti-counterfeiting detection light spot received by the photosensitive unit forms a fingerprint anti-counterfeiting image;
The target object is judged to be a two-dimensional finger or a three-dimensional finger according to the fingerprint anti-counterfeiting image, wherein the preset pattern of the anti-counterfeiting detection light spot comprises a first detection area and a second detection area with different luminous intensities, and the differential characteristic parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image are extracted to judge the target object to be the two-dimensional finger or the three-dimensional finger.
In a preferred embodiment, the first detection zone emits light at a greater intensity than the second detection zone, which emits light at zero.
In a preferred embodiment, the area of the first detection zone is larger than the area of the second detection zone.
In a preferred embodiment, the second detection areas are discretely distributed in the anti-counterfeiting detection light spot.
In a preferred embodiment, the differential characteristic parameter comprises a gray value or a contrast of the gray value of the fingerprint image of the anti-counterfeiting area corresponding to the preset pattern anti-counterfeiting detection light spot in the fingerprint anti-counterfeiting image.
In a preferred embodiment, the optical fingerprint identification and anti-counterfeiting method may further include setting a threshold range for the differential feature parameter, and determining whether the target object is a two-dimensional finger or a three-dimensional finger according to whether the differential feature parameter is within the threshold range.
In a preferred embodiment, the fingerprint anti-counterfeiting image comprises a first imaging region corresponding to the first detection region, a transition region adjacent to the first imaging region and a second imaging region corresponding to the second detection region, wherein the transition region is positioned between the first imaging region and the second imaging region.
In a preferred embodiment, the anti-counterfeiting detection light spot of the preset pattern comprises a plurality of discrete second detection areas.
An optical fingerprint identification and anti-counterfeiting system is applied to electronic equipment with a fingerprint identification area and comprises an optical identification and anti-counterfeiting device and a control unit;
the optical identification and anti-counterfeiting device comprises:
the detection light source irradiates an object to be identified on the fingerprint identification area of the electronic equipment;
an optical functional unit arranged below the fingerprint identification area for receiving the light signal reflected by the object to be identified, and
The photosensitive unit is arranged below the optical functional unit and receives the optical signals processed by the optical functional unit to form a fingerprint sensing image;
The control unit controls the detection light source to serve as an identification light source and an anti-counterfeiting light source respectively, when the electronic equipment performs fingerprint identification anti-counterfeiting on an identification object, the system controls the detection light source to form anti-counterfeiting detection light spots with preset patterns, the preset patterns of the anti-counterfeiting detection light spots comprise a first detection area and a second detection area with different luminous intensities, and the control unit extracts anti-counterfeiting characteristic parameters in a fingerprint sensing image output by the photosensitive unit corresponding to the anti-counterfeiting detection light spots to judge whether the identification object is a two-dimensional image or a three-dimensional image. In a preferred embodiment, the fingerprint sensing image output by the photosensitive unit corresponding to the anti-counterfeiting detection light spot comprises a first imaging area corresponding to the first detection area, a transition area adjacent to the first imaging area and a second imaging area corresponding to the second detection area, and the transition area is located between the first imaging area and the second imaging area.
In a preferred embodiment, the first detection zone emits light at a greater intensity than the second detection zone, which emits light at zero.
The technical scheme of the invention has the following remarkable beneficial effects:
The embodiment of the invention provides an optical fingerprint identification and anti-counterfeiting method and system, which are characterized in that an anti-counterfeiting detection light spot with a preset pattern is utilized to irradiate a target object, a photosensitive unit is utilized to respectively receive fingerprint information carried by the target object under the irradiation of the fingerprint identification light spot, the fingerprint information carried by the target object received by the photosensitive unit under the irradiation of the anti-counterfeiting detection light spot forms a fingerprint anti-counterfeiting image, and then the differential characteristic parameters corresponding to a two-dimensional finger and a three-dimensional finger in the fingerprint anti-counterfeiting image are extracted to judge that the target object is the two-dimensional finger or the three-dimensional finger, so that the safety of fingerprint identification equipment can be improved.
Specific embodiments of the invention are disclosed in detail below with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not limited in scope thereby. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, proportional sizes, and the like of the respective components in the drawings are merely illustrative for aiding in understanding the present invention, and are not particularly limited. Those skilled in the art with access to the teachings of the present invention can select a variety of possible shapes and scale sizes to practice the present invention as the case may be.
FIG. 1 is a schematic diagram of an OLED under-screen module in the prior art;
FIG. 2 is a flow chart of steps of an optical fingerprint identification and anti-counterfeit method provided in an embodiment of the present invention;
FIG. 3 is a schematic diagram of a first anti-counterfeiting detection light spot according to an embodiment of the present invention;
FIG. 4 is a security image formed by a 3D real finger;
FIG. 5 is a security image formed from a 2D fake fingerprint;
FIG. 6 is a denoising enhanced image formed by subtracting a reference from an anti-counterfeit image formed by a 3D real finger of FIG. 4;
FIG. 7 is a denoising enhanced image formed by subtracting a reference from an anti-counterfeit image formed by a 2D fake fingerprint in FIG. 5;
FIG. 8 is a schematic diagram of a second anti-counterfeiting detection light spot according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of a third anti-counterfeiting detection light spot provided in an embodiment of the present invention;
FIG. 10 is a schematic diagram of a fourth anti-counterfeiting detection light spot provided in an embodiment of the present invention;
FIG. 11 is a schematic diagram of a fifth anti-counterfeiting detection light spot provided in an embodiment of the present invention;
FIG. 12 is a fingerprint anti-counterfeit image formed by irradiating the target object with the anti-counterfeit detection light spot shown in FIG. 11 corresponding to the photosensitive unit;
FIG. 13 is a fingerprint anti-counterfeit image formed by the photosensitive unit of a white-bottomed two-dimensional finger under the irradiation of the anti-counterfeit detection light spot shown in FIG. 11;
FIG. 14 is a fingerprint anti-counterfeit image formed by the photosensitive unit of the three-dimensional finger under the irradiation of the anti-counterfeit detection light spot shown in FIG. 11;
FIG. 15 is a schematic diagram showing the contrast of the gray scale variation of a three-dimensional finger with a white two-dimensional finger from the center to the edge;
FIG. 16 is a fingerprint anti-counterfeit image formed by the photosensitive unit of a two-dimensional finger with a red background under the irradiation of the anti-counterfeit detection light spot shown in FIG. 11;
FIG. 17 is a fingerprint anti-counterfeit image formed by the photosensitive unit of the three-dimensional finger under the irradiation of the anti-counterfeit detection light spot shown in FIG. 11;
FIG. 18 is a schematic diagram showing the contrast of the gray scale variation of a three-dimensional finger with a red two-dimensional finger from the center to the edge;
FIG. 19 is a schematic diagram of a sixth anti-counterfeiting detection light spot according to an embodiment of the present invention;
FIG. 20 is a schematic diagram of a seventh anti-counterfeiting detection light spot provided in an embodiment of the present invention;
FIG. 21 is a schematic diagram of an eighth anti-counterfeiting detection light spot provided in an embodiment of the present invention;
fig. 22 is a block diagram of an optical fingerprint identification and anti-counterfeiting system according to an embodiment of the present invention.
Reference numerals of the above drawings:
1. Transparent layer, 2, OLED screen, B, anti-fake detection light spot, 3, shading layer, 4, lens, 5, pixel, 20, detection light source, 30, optical function unit, 50, photosensitive unit, 6, control unit, 21, first detection area, 22, second detection area, 23, effective anti-fake detection area, 51, first imaging area, 52, second imaging area, 53, transition area.
Detailed Description
The technical solution of the present application will be described in detail below with reference to the accompanying drawings and the specific embodiments, it should be understood that these embodiments are only for illustrating the present application and not for limiting the scope of the present application, and various modifications of equivalent forms of the present application will fall within the scope of the appended claims after reading the present application.
It will be understood 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," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.
Unless defined otherwise, 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 application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
The embodiment of the invention provides an optical fingerprint identification and anti-counterfeiting method and system, which can accurately distinguish or judge whether the fingerprint is a two-dimensional fingerprint or a three-dimensional fingerprint, avoid using two-dimensional fingerprint information to replace the three-dimensional fingerprint for fingerprint identification or unlocking, and improve the safety of fingerprint identification.
The optical fingerprint identification and anti-counterfeiting method is applied to a mobile phone communication device for example, but is not limited to other electronic devices, such as fingerprint locks, or other electronic devices needing to be identified and unlocked by fingerprints.
In common mobile phone communication equipment, the display screen of the mobile phone is an OLED screen which is more commonly used. According to the description of the prior art for OLED screens, the OLED screen can be understood as a self-luminous display screen. Thus, in the description of this embodiment, the OLED screen may be used as a detection light source for fingerprint detection. For example, on an OLED screen of a mobile phone, an OLED pixel array in a fingerprint sensing area can emit light spots to illuminate a finger to collect a fingerprint of a user. The conventional spot for capturing a fingerprint image may be circular or other in shape, hereinafter referred to as a fingerprint identification spot.
The fingerprint recognition light spot can be any light spot with a preset pattern or a full-bright light spot, which is not limited herein. When fingerprint identification is performed, as the fine fingerprint characteristics of the identification object need to be extracted, the full bright light spots are the forms commonly adopted by the fingerprint identification spots. The fingerprint recognition spot may include, for example, any one of a spot of a solid color having the same brightness formed in the fingerprint recognition area, for example, a spot formed of a single color of red, green, blue, etc., or a spot of a composite color formed of a combination of different colors in a predetermined ratio. In the optical fingerprint recognition device, when the main body of the optical processing member above the photosensitive unit is an optical lens, in order to solve the problem of relative illumination of the optical lens, the fingerprint recognition light spot can be a gradual change light spot. And forming a gradual change light spot with brightness gradually brightening from the center to the periphery in the fingerprint identification area. The size, shape, arrangement, etc. of the gradient light spot for fingerprint identification may be different according to the composition distribution of the hardware structure of the device. When the fingerprint identification light spot is a gradual change light spot which gradually lightens from the center to the periphery, the brightness of the center and the edge area of the fingerprint image collected by the photosensitive unit is uniform, so that the problem of relative illumination of the optical lens is relieved.
It should be noted that, in the optical fingerprint identification and anti-counterfeiting method according to the present application, fingerprint anti-counterfeiting and fingerprint identification are separately performed. The fingerprint identification light spots are used for fingerprint identification, the anti-counterfeiting detection light spots of the preset patterns are used for counterfeiting, and whether the target object to be identified is a two-dimensional finger or a three-dimensional finger is judged. The optical fingerprint identification and the anti-counterfeiting method can be specifically set according to the specific application scene of the optical fingerprint identification and the anti-counterfeiting method, and the optical fingerprint identification and the anti-counterfeiting method are not limited in the application.
The optical fingerprint identification and anti-counterfeiting method related to the application is described below with reference to the specific drawings and some specific embodiments.
Referring to fig. 2, in an embodiment of the present application, an optical fingerprint identification and anti-counterfeiting method is provided, which may include:
S11, forming a fingerprint identification light spot, and irradiating a target object by using the fingerprint identification light spot;
s13, forming an anti-counterfeiting detection light spot with a preset pattern, and irradiating a target object by using the anti-counterfeiting detection light spot;
step S15, providing a photosensitive unit, and respectively receiving the fingerprint information carried by the target object under the irradiation of the fingerprint identification light spot and the irradiation of the anti-counterfeiting detection light spot, wherein the fingerprint information carried by the target object received by the photosensitive unit under the irradiation of the anti-counterfeiting detection light spot forms a fingerprint anti-counterfeiting image;
Step S17, judging that the target object is a two-dimensional finger or a three-dimensional finger according to the fingerprint anti-counterfeiting image, wherein the preset pattern of the anti-counterfeiting detection light spots comprises a first detection area 21 and a second detection area 22 with different luminous intensities, and extracting differentiated characteristic parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image to judge that the target object is the two-dimensional finger or the three-dimensional finger.
In a specific embodiment, the optical fingerprint identification and anti-counterfeiting development are further described. In order to perform fingerprint recognition, it is necessary to form a fingerprint recognition spot in a fingerprint recognition area and irradiate a target object with the fingerprint recognition spot. When fingerprint anti-counterfeiting is carried out, anti-counterfeiting detection light spots with preset patterns are formed in the fingerprint identification area, and the target object is irradiated by the anti-counterfeiting detection light spots.
In particular embodiments of the optical fingerprint identification and anti-counterfeiting method described herein, the method may utilize an optical fingerprint identification and anti-counterfeiting device. The optical fingerprint identification and anti-counterfeiting device comprises a photosensitive unit. The photosensitive unit is usually presented in the optical fingerprint identification and anti-counterfeiting device in a semiconductor chip mode, and is used for receiving the optical signal reflected by the target object and performing optical imaging on the optical signal processed by the optical functional unit of the optical fingerprint identification and anti-counterfeiting device. When fingerprint identification is carried out, the photosensitive unit receives fingerprint information carried by the target object when the fingerprint identification light spot irradiates. When the fingerprint is anti-fake, the photosensitive unit receives fingerprint information carried by the target object under the irradiation of the anti-fake detection light spot to form a fingerprint anti-fake image. And judging whether the target object is a two-dimensional finger or a three-dimensional finger according to the fingerprint anti-counterfeiting image.
The fingerprint anti-fake image comprises a fingerprint anti-fake image, wherein the preset pattern of the anti-fake detection light spot comprises a first detection area and a second detection area with different luminous intensities, and the target object is judged to be a two-dimensional finger or a three-dimensional finger by extracting different characteristic parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-fake image. The following is an example and description of some specific preset patterns of anti-counterfeit detection spots.
Please refer to the preset pattern of the anti-counterfeit detection light spot shown in fig. 3. The first detection area is a thin strip with light emission, and the second detection area is a thick strip with no light emission. The first detection areas and the second detection areas are alternately and repeatedly arranged to form anti-counterfeiting detection light spots B with the preset pattern.
Fig. 4 to fig. 7 are diagrams of fingerprint anti-counterfeiting images formed by anti-counterfeiting detection light spots B of the preset pattern shown in fig. 3, which are received by the photosensitive unit. Wherein fig. 6 and fig. 7 are images after the fingerprint anti-counterfeiting image is processed by a control unit in the electronic device. Fig. 4 and 5 are fingerprint security images formed by the photosensitive units. Fig. 4 is a fingerprint anti-counterfeiting image formed by the target object under the irradiation of the anti-counterfeiting detection light spot of the preset pattern shown in fig. 3 when the target object is a three-dimensional finger. Fig. 5 is a fingerprint anti-counterfeiting image formed by the target object under the irradiation of the anti-counterfeiting detection light spot of the preset pattern shown in fig. 3 when the target object is a two-dimensional finger. It can be appreciated that the bright fringes ①③⑤⑦ in fig. 4 and 5 are first imaging regions corresponding to the first detection regions of the anti-counterfeit detection spots B. Since the luminescence intensity of the second detection area is zero, the dark place without the fingerprint in fig. 4 and 5 can be understood as the second imaging area corresponding to the second detection of the anti-counterfeiting detection light spot B. As can be seen by comparing fig. 4 and 5, there is a more pronounced difference in the transition region ②④⑥ between the first imaging region and the second imaging region. The fingerprint anti-counterfeiting images of fig. 4 and 5 are subjected to algorithm optimization by using a control unit in the electronic equipment to correspondingly obtain fig. 6 and 7. It can be seen that the fingerprint features within the transition region shown in fig. 6 are significantly different from the transition region fingerprint features shown in fig. 7.
The person skilled in the art can judge whether the target object is a two-dimensional finger or a three-dimensional finger by extracting the differential characteristic parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image. For example, a threshold range is set for the contrast of fingerprint ridges in the transition region, or by extracting the slope of the change in the fingerprint information of the transition region, etc. The two-dimensional and three-dimensional target object can be discriminated by extracting the differential features through the control unit by utilizing different algorithms due to the discrimination which can be distinguished by naked eyes. The extraction of this differentiated feature is not further illustrated here.
Therefore, three-dimensional and two-dimensional discrimination of the target object can be realized by utilizing the anti-counterfeiting detection light spot B with the preset pattern shown in fig. 3. The optical functional unit main body in the optical fingerprint identification and anti-counterfeiting device verified by the anti-counterfeiting detection light spot B of the anti-counterfeiting pattern is an optical lens. Optical fingerprint identification and anti-counterfeiting devices such as optical lenses. When the anti-fake detection light spot B with the preset pattern irradiates the two-dimensional finger and the three-dimensional finger, the fingerprints corresponding to the transition areas in the first detection area and the second detection area on the photosensitive unit have obvious differences, and the difference of the images is utilized to extract the differentiation parameters so as to judge whether the target object is the two-dimensional finger or the three-dimensional finger.
Fig. 8 to 10 further illustrate the anti-counterfeit detection spots B of various patterns. As shown in fig. 10, the anti-counterfeit detection light spot B may be an annular stripe light spot with alternate brightness extending from the center to the periphery. When the anti-counterfeiting detection light spot B is the annular stripe light spot, the anti-counterfeiting detection light spot B is a two-dimensional light spot, so that the differential fingerprint characteristics of different dimensions of the fingerprint anti-counterfeiting image can be expanded. As shown in fig. 8, the anti-counterfeiting detection light spot B may be a grid light spot extending along a first direction and a second direction perpendicular to the first direction with light and dark alternately. As shown in fig. 9, the anti-counterfeit detection spot B may be a plurality of discontinuous light emitting parts formed on the non-light emitting region. Specifically, the light emitting portion may have a cross shape as shown in fig. 9, and of course, the light emitting portion may have other shapes, which is not particularly limited herein.
The fingerprint anti-counterfeiting images formed by the photosensitive units corresponding to fig. 8 to 10 are not illustrated one by one. In general, the anti-counterfeiting detection light spots B of the patterns are similar to the stripe-shaped anti-counterfeiting detection light spots shown in fig. 3, and different fingerprint images are generated in the transition areas between the first imaging areas and the second imaging areas of the corresponding photosensitive units for two-dimensional and three-dimensional target objects, so that the discrimination of whether the target object is a two-dimensional finger or a three-dimensional finger can be realized.
As shown in fig. 3, the anti-counterfeiting detection light spot B may be a stripe light spot extending along the first direction and having alternately bright and dark stripes. Compared with the anti-fake detection light spots of other enumerated patterns, the anti-fake detection light spot B of the pattern has better robustness due to lower calibration requirements on the system positions. In the anti-counterfeiting retrieval light spot with the preset pattern, the area of the dark stripe is larger than that of the bright stripe, wherein the width ratio of the bright stripe to the dark stripe can be 3:17.
In this embodiment, the anti-counterfeit detection light spot B may be a one-dimensional light spot, for example, a line pair light spot, as shown in fig. 3, which is beneficial to reducing complexity of subsequent image and data processing, and is beneficial to ensuring accuracy and reliability of anti-counterfeit fingerprint identification. In addition, the cost of forming the anti-counterfeiting detection light spot B is relatively low. The anti-counterfeiting detection light spot B is provided with stripe light spots which are alternately bright and dark and extend along the first direction. The bright stripes and the dark stripes of the stripe light spots are parallel to each other. Experiments show that the width ratio of the bright stripes to the dark stripes is 3:17, so that the anti-fake image capable of obviously identifying the 2D fake fingerprint (namely the two-dimensional fake finger) can be formed. However, when the function of the algorithm anti-counterfeiting module in the control unit of the electronic equipment is stronger, even if the two-dimensional and three-dimensional models of the same fingerprint in the fingerprint anti-counterfeiting image have no obvious fingerprint differences of the two-dimensional fake finger and the three-dimensional finger, the minutely differentiated fingerprint characteristic parameters can be extracted for anti-counterfeiting.
The second detection area in the pattern of the anti-counterfeiting detection light spot B has zero luminous brightness. The formation of such a pattern is relatively easy to control and implement for the anti-counterfeit detection spot B forming the predetermined pattern. In particular, when the pattern of the anti-counterfeiting detection light spot B is realized by using the luminous pixels of the pattern recognition area in the OLED display screen, when the brightness of the second detection area is zero, the control of the anti-counterfeiting detection light spot B of various patterns is simple and easy to realize. It should be understood that, in other embodiments, the brightness of the second detection area in the pattern of the anti-counterfeit detection light spot B may be lower than that of the first detection area, so that the first detection area and the second detection area may still form the anti-counterfeit detection light spot B with the preset pattern. The anti-counterfeiting detection light spot B with the preset pattern can also enable the two-dimensional target object and the three-dimensional target object to generate differentiated fingerprint images on the photosensitive unit.
The anti-counterfeiting detection light spots B of the patterns listed above have fingerprint differences of transition areas in the fingerprint anti-counterfeiting images formed by the photosensitive units for two-dimensional and three-dimensional target objects of the same fingerprint. However, since the areas of the dark areas of the anti-counterfeiting detection light spots B of the patterns are larger than the areas of the bright areas, when the anti-counterfeiting detection light spots B of the patterns are irradiated to a target object, the photosensitive unit needs longer exposure time to form a fingerprint anti-counterfeiting image, and when the anti-counterfeiting detection light spots B are used for anti-counterfeiting fingerprint screening, the time consumption is slightly long. Because fingerprint identification and anti-counterfeiting are separated, the time required by the electronic equipment when the optical fingerprint identification and anti-counterfeiting method is applied exceeds the expected time, and the experience of the terminal user is easy to be slightly poor.
In order to solve the problem that when the photosensitive unit forms the fingerprint anti-counterfeiting image due to the anti-counterfeiting detection light spot B of the pattern with larger dark area occupation, the exposure time is too long, the anti-counterfeiting detection light spot B with larger bright area is provided, and the two-dimensional finger and the three-dimensional finger can form a differential fingerprint anti-counterfeiting image on the photosensitive unit.
Please refer to fig. 11, which illustrates an anti-counterfeit detection spot B of the pattern. The middle part of the anti-fake detection light spot B is a second detection area 22, and a first detection area 21 is arranged outside the second detection area 22. The anti-counterfeit detection spot B shown in fig. 11 lacks the annular second detection region 22 surrounding the middle portion, as compared to the pattern of the anti-counterfeit detection spot B shown in fig. 10. Therefore, compared with the pattern shown in fig. 10, the area ratio of the second detection area 22 to the whole anti-fake detection spot B in the pattern shown in fig. 11 is reduced, and the ratio of the first detection area 21 with brighter brightness is increased, which is beneficial to reducing the exposure time required for the photosensitive unit to form the fingerprint anti-fake image. The second detection area 22 of the anti-counterfeit detection spot B shown in fig. 11 does not emit light for illustration.
Fig. 12 shows a fingerprint anti-counterfeit image formed by irradiating the target object with the anti-counterfeit detection light spot B of the preset pattern shown in fig. 11 and the corresponding photosensitive unit. The second imaging area 52 is an imaging position corresponding to the second detection area 22 in the photosensitive unit, and the first imaging area 51 is an imaging position corresponding to the first detection area 21 in the photosensitive unit. There is a transition region 53 between the first imaging region 51 and the second imaging region 52.
Referring to fig. 13, 14, 16 and 17, fig. 12, 13, 14 and 16 and 17 are fingerprint anti-counterfeiting images formed by irradiating anti-counterfeiting detection light spots B of the pattern shown in fig. 11 to fingerprints to be identified. The two-dimensional fingerprint and the three-dimensional fingerprint are significantly different in the transition area 53 defined in fig. 12 in the fingerprint security images shown in fig. 13, 14 and 16 and 17. The area within the boundary of the transition area 53 defined in the fingerprint security image shown in fig. 12, which corresponds to the boundary in the first detection area 21 on the security detection spot B, is the effective security detection area 23.
Fig. 13 is a fingerprint anti-counterfeiting image formed by the photosensitive unit of the white-background two-dimensional finger under the irradiation of the anti-counterfeiting detection light spot B shown in fig. 11, and fig. 14 is a fingerprint anti-counterfeiting image formed by the photosensitive unit of the three-dimensional finger under the irradiation of the anti-counterfeiting detection light spot B shown in fig. 11. As can be seen by comparing fig. 13 and fig. 14, the differences between the fingerprint anti-counterfeiting images of the white-bottomed two-dimensional finger and the three-dimensional finger are very significant in the transition region for the anti-counterfeiting detection light spot B shown in fig. 11.
The gray scale curve changes of the fingerprint anti-counterfeiting images in fig. 13 and 14 are combined into one fingerprint anti-counterfeiting image, and the distribution is shown in fig. 15. Since the reflectivity of the white background of the two-dimensional finger is higher and the reflected light is concentrated in the mirror image direction, the gray scale of the fingerprint anti-counterfeiting image of the two-dimensional finger with the white background in the boundary area of the transition area 53 is obviously higher than that of the fingerprint anti-counterfeiting image of the three-dimensional finger in the boundary area of the transition area 53. The gray level attenuation speed of the transition area 53 of the fingerprint anti-counterfeiting image of the two-dimensional finger towards the center direction of the second imaging area is faster than the gray level attenuation speed of the transition area 53 of the fingerprint anti-counterfeiting image of the three-dimensional finger towards the center direction of the second imaging area. Briefly, this phenomenon may be explained from an optical perspective in that the three-dimensional finger may receive more scattered light and more reflected light in a larger angular region at the second imaging region 52, so that the gray scale of the second imaging region 52 of the three-dimensional finger anti-counterfeit image is higher than the gray scale of the second imaging region 52 of the two-dimensional finger with a white background. It can be understood that, in fig. 15, the difference between the two fingerprint security images in fig. 13 and 14 is shown in terms of the gray scale value of the fingerprint, the gray peak value of the white-bottomed two-dimensional finger in the transition area 53 is higher than the gray scale value of the three-dimensional finger in the transition area 53, the gray scale value of the white-bottomed two-dimensional finger in the second imaging area 52 is lower than the gray scale value of the three-dimensional finger in the second imaging area 52, and the gradient of the gray scale change of the white-bottomed two-dimensional finger in the transition area 53 is greater than the gradient of the gray scale change of the three-dimensional finger. In fig. 15, F represents a gray level change rule curve of the fingerprint anti-counterfeiting image corresponding to the three-dimensional finger, and W represents a gray level change rule curve of the fingerprint anti-counterfeiting image corresponding to the white-background two-dimensional finger. In the graph of fig. 15, the abscissa indicates the image pixel position, and the ordinate indicates the domain gray scale average value.
Here, fig. 15 is only an illustration of one extraction method of the differentiated fingerprint features in the two fingerprint anti-counterfeit images of fig. 13 and 14, and is used to illustrate that the anti-counterfeit detection light spot B shown in fig. 11 can be used to discriminate a two-dimensional finger from a three-dimensional finger, and is not limited to the extraction method of the two fingerprint anti-counterfeit images of fig. 13 and 14 by using other differentiated features to discriminate the two-dimensional finger from the three-dimensional finger.
Fig. 16 is a fingerprint anti-counterfeiting image formed by the photosensitive unit of the red-background two-dimensional finger under the irradiation of the anti-counterfeiting detection light spot B shown in fig. 11, and fig. 17 is a fingerprint anti-counterfeiting image formed by the photosensitive unit of the three-dimensional finger under the irradiation of the anti-counterfeiting detection light spot B shown in fig. 11. As can be seen by comparing fig. 16 and 17, for the anti-counterfeiting detection light spot B shown in fig. 1, the anti-counterfeiting image of the fingerprint of the red-bottomed two-dimensional finger is darker than the anti-counterfeiting image of the fingerprint of the three-dimensional finger as a whole.
As shown in fig. 18, the gray scale distribution of the two fingerprint anti-counterfeiting images in fig. 16 and 17 is integrated into one image and is displayed in a contrasting manner by using a curve. Wherein F represents the gray level change rule curve of the fingerprint anti-counterfeiting image formed by the photosensitive unit from the center to the edge under the irradiation of the anti-counterfeiting detection light spot B of the pattern shown in fig. 11, and R represents the gray level change rule curve of the fingerprint anti-counterfeiting image formed by the photosensitive unit from the center to the edge under the irradiation of the anti-counterfeiting detection light spot B of the pattern shown in fig. 11. In fig. 18, the abscissa in the coordinate axis is the image pixel position, and the ordinate is the domain gray scale average value. Because the reflectivity of the red-background two-dimensional finger is lower, the gray level of the corresponding fingerprint anti-counterfeiting image in the transition area 53 is lower than that of the transition area of the three-dimensional finger fingerprint anti-counterfeiting image, and the second imaging area 52 in the fingerprint anti-counterfeiting image of the three-dimensional finger can receive more scattered light and reflected light in a larger angle area, the gray level of the three-dimensional finger image in the second imaging area 52 is obviously higher than that of the second imaging area 52 in the fingerprint anti-counterfeiting image of the red-background two-dimensional finger.
For the extraction mode of the differential parameters in the fingerprint anti-counterfeiting images of the two-dimensional finger and the three-dimensional finger shown in fig. 15 and 18, the control unit in the specific available electronic equipment can be used for further calculation. As seen in fig. 15 and 18, the gray level of the three-dimensional finger in the second imaging area is higher than the gray level of the two-dimensional finger in the second imaging area. Although the two-dimensional finger and the three-dimensional finger can be distinguished by using the gray value range, in order to improve the accuracy of the judging result, the judging result can be obtained more reliably by adopting the relative result of the multi-point numerical value to judge.
The specific extraction method of the differential fingerprint characteristic parameters of the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image corresponding to the anti-counterfeiting detection light spot B shown in fig. 11 is described below. For example, the control unit calculates the average gray level of the fingerprint anti-counterfeit image located in the transition area 53 as R1, calculates the average gray level of the fingerprint anti-counterfeit image located in the second imaging area 52 as R2, and determines a three-dimensional finger when R2/R1 is greater than the anti-counterfeit determination threshold value. Wherein, the anti-counterfeiting judgment threshold value can be 0.2. And when R2/R1 is larger than the anti-counterfeiting judgment threshold value, judging that the finger is a true finger, and otherwise, judging that the finger is a false finger.
Referring to fig. 15 and fig. 18, if the average value of the gray scales of the second imaging region 52 and the transition region 53 is used as the determination condition, it is required to ensure that the peaks and the troughs of the gray scales in the fingerprint anti-counterfeit image exist. As described above, in the anti-counterfeit detection spot B shown in fig. 11, not all the areas of the first detection region 21 are beneficial to the formation of the significantly differentiated areas in the fingerprint anti-counterfeit image, so that the effective anti-counterfeit detection region 23 corresponds to the imaging area of the photosensitive unit that is actually used by the specific differentiated feature extraction method described above. Under the specific conditions of the optical parameters of the optical lens and the size of the photosensitive unit in the optical fingerprint identification and anti-counterfeiting device, the radius of the effective anti-counterfeiting detection area 23 corresponding to the effective fingerprint gray-scale peak and trough differential feature extraction main area can be formed to be about 40 pixel points. The radius of the second detection area 22 currently set in fig. 13, 14, 16, and 17 is about 20 pixels. Under the condition that the parameters of the optical lens are fixed, the area of the effective anti-counterfeiting detection area 23 is relatively fixed, and under the condition that the radius of the second detection area 22 is adjusted to be 15 to 25 pixels, the two-dimensional finger and the three-dimensional finger can be still distinguished according to the specific extraction mode of the differential fingerprint characteristic parameters. Therefore, the area of the second detection area 22 in the effective anti-counterfeiting detection area 23 is about 14% to 40%. This duty cycle can be adjusted with the optical parameters in the optical fingerprint identification and anti-counterfeiting device actually applied.
As described above in relation to the security detection spot B of the pattern shown in fig. 11, not all of the first detection zone 21 is helpful in forming the differentiated feature portion in the fingerprint security image, and only the effective security detection zone 23 in the overall pattern is helpful in extracting the differentiated feature parameters in the fingerprint security image. In order to prevent the finger from being pressed to the central area of the anti-counterfeiting detection light spot B, when the anti-counterfeiting judgment result is affected, a plurality of discrete second detection areas 22 may be disposed in the anti-counterfeiting detection light spot B. The number of the second detection areas 22 is specifically set, and the number of the second detection areas 22 and the arrangement of the plurality of second detection areas 22 may be set according to the size of the area of the effective anti-counterfeiting detection area 23 and the size of the anti-counterfeiting detection light spot B described above.
The shapes of the plurality of discrete second detection areas 22 may be the same or different, and the shapes of the plurality of second detection areas 22 may be set as desired. For the arrangement of the plurality of second detection areas 22, the arrangement can be performed relatively flexibly. For example, as shown in fig. 19 to 21, a plurality of second detection areas 22 may be arranged so as to be discretely distributed in the anti-counterfeit detection spot B. The plurality of second detection areas 22 shown in fig. 19 are arranged in a rectangular array. Specifically, the plurality of non-light emitting pattern units are arranged in an equidistant rectangular manner to form a rectangular pattern array of m×n, optionally, M may be selected from 2,3,4, and N may be selected from 2,3,4. Or as shown in fig. 20 or 21, the plurality of second detection areas 22 are discretely distributed in the form of an annular array in the anti-counterfeit detection spot B. In particular, the plurality of second detection areas 22 are distributed in a circular equidistant fashion. The main difference between the anti-counterfeit detection spot B shown in fig. 20 and 21 is that the area of the second detection region 22 located at the center in fig. 20 may be smaller than the area of the second detection region 22 located at the center in fig. 21.
In the case of anti-counterfeit detection by using the anti-counterfeit detection spot B of any one of the patterns shown in fig. 19 to 21, a plurality of second imaging regions 52 and a transition region surrounding the second imaging regions 52 are also formed on the photosensitive unit. Taking the mode that the ratio of the average value of the gray scales of the second imaging areas 52 to the average value of the transition areas is larger than the anti-counterfeiting judging threshold value as an example, judging that the target finger is a two-dimensional finger and a three-dimensional finger, respectively obtaining judging results corresponding to each second imaging area 52 in N groups, wherein when the judging result of the M groups is that the target object is a three-dimensional true finger, and simultaneously, when the ratio of M/N is larger than the anti-counterfeiting judging ratio, the detected target finger can be judged to be the three-dimensional true finger. Wherein, the anti-counterfeiting judging proportion can be 40%. The ratio of the anti-counterfeit detection can be specifically set according to the number of the second detection areas 22 in the anti-counterfeit detection light spot B, the number of the second detection areas 22 covered by the finger, and other conditions.
The exemplary patterns of the anti-counterfeiting detection light spot B of fig. 19 to 21 are merely exemplary patterns of the plurality of second detection areas 22, wherein the shape of the second detection areas 22 is illustrated along the circular shape of the second detection areas 22 illustrated in fig. 11, and the scope of the present application is not limited to be construed as being limited.
In other embodiments, the first detection area 21 may be a dark area and the second detection area 22 may be a bright area in the pattern of the anti-counterfeit detection spot B. That is, in fig. 11, the luminous intensities of the first detection area 21 and the second detection area 22 in the anti-counterfeit detection spot B with such a bright area occupying a relatively large area may be interchanged. The target fingerprint irradiated by the anti-counterfeiting detection light spot B with larger difference in brightness passes through the optical lens, a transition area of a bright-dark boundary is formed on the photosensitive unit, and the imaging of the two-dimensional finger and the three-dimensional finger in the transition area has obvious difference. The control unit can realize the discrimination of the two-dimensional finger and the three-dimensional finger by extracting the differences.
The extraction of the differential characteristic parameters in the fingerprint anti-counterfeiting images corresponding to the two-dimensional finger and the three-dimensional finger is not limited to the above-listed modes. The differential characteristic parameters of the two fingerprint anti-counterfeiting images can be extracted from the angle of fingerprints, such as the gray level or gray level ratio of the fingerprints in the collected specific area, however, the differential characteristic extraction can also be performed from the angle of the images, and the discrimination of the two-dimensional finger and the three-dimensional finger can be performed by the difference of the gray level distribution of the images in different areas of the fingerprint anti-counterfeiting images formed by the detection of the anti-counterfeiting detection light spots of the preset patterns. Since the extraction mode of the differential feature parameters can have a plurality of different implementation modes, the image processing mode can also have a plurality of different implementation modes, and the exhaustion cannot be performed.
From the pattern of the anti-fake detection light spot B provided above, the discrimination of the two-dimensional finger and the three-dimensional true finger can be realized by extracting the differential features in the fingerprint anti-fake image correspondingly formed on the photosensitive unit. The anti-fake detection light spot B corresponds to the fingerprint anti-fake image formed on the photosensitive unit, so that the fingerprint features with differences in transition areas of the fingerprint anti-fake image can be extracted to further realize two-dimensional and three-dimensional finger discrimination, or the different fingerprint features with different distributions in transition areas 53 and second imaging areas 52 in the fingerprint anti-fake image can be extracted to discriminate. In general, the specific way of extracting the differentiated fingerprints may be chosen according to the configuration of the actual electronic device control unit. On the premise that the patterns of the anti-counterfeiting detection light spots B are obviously different for the anti-counterfeiting images of the fingerprints formed on the photosensitive units of the two-dimensional finger and the three-dimensional finger.
Through multiple experiments and comparison, the first detection area 21 and the second detection area 22 with different brightness are arranged on the anti-counterfeiting detection light spot B, and as the real three-dimensional finger and the two-dimensional finger have larger difference in reflectivity, reflected light and other parameters in the imaging process, the anti-counterfeiting images of the fingerprints obtained through the photosensitive units also have difference, and particularly, the difference of transition areas of the brightness boundary in the anti-counterfeiting images of the fingerprints is obvious. For the anti-fake detection light spot B with larger dark area, in order to make the fingerprint anti-fake image have obvious difference for the two-dimensional finger and the three-dimensional finger, the ratio of the dark area to the bright area is in a certain threshold range, and the difference between the fingerprint anti-fake images corresponding to the three-dimensional real finger and the two-dimensional fake finger is obvious. If the defect can be overcome by the configuration of the control unit, the problem caused by the fact that the dark area of the anti-counterfeiting detection light spot B occupies a relatively large area can not influence the experience of a user in using the optical fingerprint identification and anti-counterfeiting system in the electronic equipment even if the electronic equipment terminal is applied. Meanwhile, the pattern of the anti-counterfeiting detection light spot B with a large area of a bright area and the extraction of the anti-counterfeiting characteristics are also illustrated. The embodiment has the obvious advantage that the exposure time required by the photosensitive unit when forming the fingerprint anti-counterfeiting image can be saved, namely the time required by the optical fingerprint anti-counterfeiting stage can be shortened compared with the anti-counterfeiting detection light spot B with a larger dark area.
The anti-counterfeiting detection light spot B comprising the preset patterns formed by the two detection areas with different brightness degrees irradiates the target fingerprint, the optical recognition and the optical lens of the anti-counterfeiting device process the optical signals reflected by the target fingerprint, and the photosensitive unit arranged below the optical lens can form the fingerprint anti-counterfeiting image. The subsequent control unit can process the fingerprint anti-counterfeiting image according to a preset extraction mode of the differential characteristic parameters to judge whether the target fingerprint is a two-dimensional finger or a three-dimensional true finger. The specific differential feature extraction approach has been illustrated in the foregoing and is not exhaustive and therefore will not be repeated here.
It should be appreciated that, although the above description merely illustrates the formation of the anti-counterfeiting detection light spot B by using the OLED screen, for a non-self-luminous display screen, the method of subsequent identification and anti-counterfeiting is substantially the same as the above-described embodiment when the detection light is directed to the surface of the pressed object by using the internal light source or the external light source by using the light path, and thus the description will not be repeated.
The optical fingerprint identification and anti-counterfeiting method introduced above is applied to an optical fingerprint identification and anti-counterfeiting system formed by electronic equipment.
The optical fingerprint identification and anti-counterfeiting system comprises an optical identification and anti-counterfeiting device and a control unit 6, as described in connection with fig. 22. The optical recognition and anti-counterfeiting device comprises a detection light source 20, an optical function unit 30 and a photosensitive unit 50. The probe light source 20 irradiates an object to be identified on the fingerprint identification area of the electronic device. If the detection light source is realized by using the display screen which automatically emits light by the electronic equipment, the detection light source is arranged in the display screen, namely the detection light source is composed of luminous pixels in the display screen. The optical functional unit 30 is disposed below the fingerprint recognition area, and receives the optical signal reflected by the object to be recognized. The optical functional unit is an optical processing component mainly comprising an optical lens. The photosensitive unit 50 is disposed below the optical functional unit, and receives the optical signal processed by the optical functional unit to form a fingerprint sensing image.
Wherein the control unit 6 controls the detection light source 20 to serve as an identification light source and an anti-counterfeiting light source respectively. When the electronic device performs fingerprint identification and anti-counterfeiting on the identification object, the system controls the detection light source 20 to form an anti-counterfeiting detection light spot B with a preset pattern. The control unit 6 extracts the anti-counterfeiting characteristic parameters in the fingerprint sensing image output by the anti-counterfeiting detection light spot B corresponding to the photosensitive unit 50 to judge whether the object to be identified is a two-dimensional image or a three-dimensional image. When the electronic device performs fingerprint recognition on the recognition object, the system controls the detection light source 20 to form a recognition light spot to irradiate a target fingerprint on the fingerprint recognition area, extracts fingerprint recognition features of the target fingerprint, and matches the extracted fingerprint recognition features with fingerprint recognition features stored in advance by the control unit to judge whether the extracted fingerprint recognition features are matched with the stored fingerprint recognition features. Fingerprint identification and fingerprint anti-counterfeiting are two independent processes, and the sequence of fingerprint identification and anti-counterfeiting can be set according to specific application scenes.
When the system performs fingerprint anti-counterfeiting detection, the fingerprint sensing image output by the photosensitive unit 50 corresponding to the anti-counterfeiting detection light spot B comprises a first imaging area corresponding to a first detection area, a transition area adjacent to the first imaging area and a second imaging area corresponding to a second detection area, wherein the transition area is positioned between the first imaging area and the second imaging area. The luminous intensity of the first detection area is larger than that of the second detection area, and the luminous intensity of the second detection area is zero, so that the control and the realization of the anti-counterfeiting detection light spot B of the preset pattern are facilitated. Through the patterns of a plurality of groups of different anti-fake detection light spots B, the photosensitive unit 50 can be found to have obvious differences on the two-dimensional finger and three-dimensional finger fingerprint anti-fake images formed by the patterns of the same anti-fake detection light spots B when the anti-fake detection light spots B of a certain proportion of bright and dark connected patterns appear. The control unit 6 is used for extracting the differential characteristics of the presence rules to realize whether the target object is a two-dimensional finger or a three-dimensional finger.
It should be noted that, in the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and to distinguish between similar objects, and there is no order of preference between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.
The foregoing embodiments in the present specification are all described in a progressive manner, and the same and similar parts of the embodiments are mutually referred to, and each embodiment is mainly described in a different manner from other embodiments.
The foregoing is merely a few embodiments of the present invention, and the embodiments disclosed in the present invention are merely examples which are used for the convenience of understanding the present invention and are not intended to limit the present invention. Any person skilled in the art can make any modification and variation in form and detail of the embodiments without departing from the spirit and scope of the present disclosure, but the scope of the present disclosure is still subject to the scope of the appended claims.
Claims (9)
1. An optical fingerprint identification and anti-counterfeiting method, comprising the steps of:
forming a fingerprint identification light spot, and irradiating a target object by using the fingerprint identification light spot;
forming an anti-counterfeiting detection light spot with a preset pattern, and irradiating a target object by using the anti-counterfeiting detection light spot;
Providing a photosensitive unit, and respectively receiving the carried fingerprint information of the target object under the irradiation of the fingerprint identification light spot and the irradiation of the anti-counterfeiting detection light spot, wherein the fingerprint information carried by the target object under the irradiation of the anti-counterfeiting detection light spot received by the photosensitive unit forms a fingerprint anti-counterfeiting image;
judging the target object as a two-dimensional finger or a three-dimensional finger according to the fingerprint anti-counterfeiting image, wherein the preset pattern of the anti-counterfeiting detection light spot comprises a first detection area and a second detection area with different luminous intensities;
the fingerprint anti-counterfeiting image comprises a first imaging region corresponding to the first detection region, a transition region adjacent to the first imaging region and a second imaging region corresponding to the second detection region, wherein the transition region is positioned between the first imaging region and the second imaging region;
the step of extracting the differential characteristic parameters corresponding to the two-dimensional finger and the three-dimensional finger in the fingerprint anti-counterfeiting image to judge whether the target object is the two-dimensional finger or the three-dimensional hand comprises the following steps:
And extracting the fingerprint characteristics with differences in transition areas in the fingerprint anti-counterfeiting image so as to realize the screening of two-dimensional and three-dimensional fingers, or extracting the differential fingerprint characteristics with different distributions of the transition areas and the second imaging areas in the fingerprint anti-counterfeiting image so as to conduct the screening.
2. The optical fingerprint identification and anti-counterfeiting method according to claim 1, wherein the luminous intensity of the first detection area is larger than the luminous intensity of the second detection area, and the luminous intensity of the second detection area is zero.
3. The optical fingerprint identification and anti-counterfeiting method according to claim 2, wherein the area of the first detection area is larger than the area of the second detection area.
4. The optical fingerprint identification and anti-counterfeiting method according to claim 1, wherein the second detection areas are discretely distributed in the anti-counterfeiting detection light spots.
5. The optical fingerprint identification and anti-counterfeiting method according to claim 1, wherein the differential characteristic parameter comprises a gray value or a contrast of the gray value of the fingerprint image of an anti-counterfeiting area corresponding to a preset pattern anti-counterfeiting detection light spot in the fingerprint anti-counterfeiting image.
6. The optical fingerprint identification and anti-counterfeiting method according to claim 5, further comprising setting a threshold range for the differential feature parameter, and judging whether the target object is a two-dimensional finger or a three-dimensional finger according to whether the differential feature parameter is within the threshold range.
7. The optical fingerprint identification and anti-counterfeiting method according to claim 1, wherein the anti-counterfeiting detection light spot of the preset pattern comprises a plurality of discrete second detection areas.
8. An optical fingerprint identification and anti-counterfeiting system is applied to electronic equipment with a fingerprint identification area and is characterized by comprising an optical identification and anti-counterfeiting device and a control unit;
the optical identification and anti-counterfeiting device comprises:
the detection light source irradiates an object to be identified on the fingerprint identification area of the electronic equipment;
an optical functional unit arranged below the fingerprint identification area for receiving the light signal reflected by the object to be identified, and
The photosensitive unit is arranged below the optical functional unit and receives the optical signals processed by the optical functional unit to form a fingerprint sensing image;
Wherein the control unit controls the detection light source to be respectively used as an identification light source and an anti-counterfeiting light source, when the electronic equipment performs fingerprint identification anti-counterfeiting on an identification object, the system controls the detection light source to form anti-counterfeiting detection light spots with preset patterns, the preset patterns of the anti-counterfeiting detection light spots comprise a first detection area and a second detection area with different luminous intensities, the control unit extracts anti-counterfeiting characteristic parameters in a fingerprint sensing image output by the photosensitive unit corresponding to the anti-counterfeiting detection light spots to judge whether the identification object is a two-dimensional image or a three-dimensional image,
The fingerprint sensing image output by the photosensitive unit corresponding to the anti-counterfeiting detection light spot comprises a first imaging area corresponding to the first detection area, a transition area adjacent to the first imaging area and a second imaging area corresponding to the second detection area, wherein the transition area is positioned between the first imaging area and the second imaging area;
The control unit extracting the anti-counterfeiting characteristic parameters in the fingerprint sensing image output by the anti-counterfeiting detection light spot corresponding to the photosensitive unit to judge whether the object to be identified is a two-dimensional image or a three-dimensional image comprises the following steps:
And extracting the fingerprint characteristics with differences in transition areas in the fingerprint anti-counterfeiting image so as to realize the screening of two-dimensional and three-dimensional fingers, or extracting the differential fingerprint characteristics with different distributions of the transition areas and the second imaging areas in the fingerprint anti-counterfeiting image so as to conduct the screening.
9. The optical fingerprint identification and security system of claim 8, wherein the first detection zone has a luminous intensity greater than the luminous intensity of the second detection zone, and wherein the luminous intensity of the second detection zone is zero.
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| CN115063841A (en) * | 2021-02-27 | 2022-09-16 | 华为技术有限公司 | A fingerprint verification method and electronic device |
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| US11620852B2 (en) * | 2021-09-08 | 2023-04-04 | Omnivision Technologies, Inc. | Method for detecting spoof fingerprints with an under-display fingerprint sensor |
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| CN110582780A (en) * | 2019-08-01 | 2019-12-17 | 深圳市汇顶科技股份有限公司 | Fingerprint identification and anti-counterfeiting method and device and electronic equipment |
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| CN113139414A (en) | 2021-07-20 |
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