Calibration method, anti-counterfeiting identification method, electronic device and computer readable medium

Abstract

Embodiments of the present application disclose a calibration method, a counterfeit identification method, an electronic device and a computer readable medium. An embodiment of the method comprises: controlling a polarized light source to emit first polarized light and second polarized light with different polarization angles at different times, and acquiring light intensity distribution information of the first polarized light and the second polarized light respectively; determining calibration information based on the light intensity distribution information, the calibration information being used to represent a light intensity distribution difference between the first polarized light and the second polarized light; when the polarized light source is controlled to emit the first polarized light and the second polarized light at different times again and the first polarized light and the second polarized light are reflected by a target object and then enter a polarization camera, acquiring a first image and a second image by the polarization camera, and calibrating the first image or the second image based on the calibration information. The embodiment can eliminate or greatly weaken the interference introduced by the light intensity distribution difference of different polarized light in the two images, thereby helping to improve the accuracy of the counterfeit identification based on polarized light.

Description

Technical Field

[0001] This application relates to the field of computer technology, specifically to calibration methods, anti-counterfeiting identification methods, electronic devices, and computer-readable media. Background Technology

[0002] In recent years, anti-counterfeiting identification technology based on polarized light has gradually emerged. This technology uses polarized light at different angles to enable the imaging module to obtain images under polarized light at different angles, and then analyzes the differences between the images to distinguish whether the subject is a living person.

[0003] In existing technologies, after illuminating two polarized lights with different polarization angles at different times and acquiring images, the two images are directly analyzed for differences. However, due to limitations in manufacturing processes and material properties, there are often differences in light intensity distribution between light source components that generate different polarized lights, or even within the same component emitting different polarized lights. These differences can interfere with subsequent image difference analysis, severely reducing the accuracy of anti-counterfeiting identification based on polarized light. Summary of the Invention

[0004] This application proposes a calibration method, an anti-counterfeiting identification method, an electronic device, and a computer-readable medium, which can eliminate or significantly reduce the interference introduced by the difference in light intensity distribution of different polarized light in two images, thereby helping to improve the accuracy of anti-counterfeiting identification based on polarized light.

[0005] In a first aspect, embodiments of this application provide a calibration method, which includes: controlling the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquiring light intensity distribution information of the first polarized light and the second polarized light respectively; determining calibration information based on the light intensity distribution information, wherein the calibration information is used to characterize the difference in light intensity distribution between the first polarized light and the second polarized light; when the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner again and they are reflected by the target object and then incident on the polarization camera, a first image and a second image are acquired by the polarization camera, and the first image or the second image is calibrated based on the calibration information.

[0006] Secondly, embodiments of this application provide a calibration device, comprising: an acquisition unit, configured to control the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquire light intensity distribution information of the first polarized light and the second polarized light respectively; a determination unit, configured to determine calibration information based on the light intensity distribution information, the calibration information being used to characterize the difference in light intensity distribution between the first polarized light and the second polarized light; and a calibration unit, configured to, when the polarization light source is again controlled to emit the first polarized light and the second polarized light in a time-division manner and they are reflected by a target object and then incident on a polarization camera, acquire a first image and a second image through the polarization camera, and calibrate the first image or the second image based on the calibration information.

[0007] Thirdly, embodiments of this application provide an anti-counterfeiting identification method, which includes: performing anti-counterfeiting identification on a target object based on a second image and a calibrated first image, or performing anti-counterfeiting identification on a target object based on a first image and a calibrated second image; wherein the calibrated first image or the calibrated second image is an image calibrated by the calibration method described in the first aspect.

[0008] Fourthly, embodiments of this application provide an anti-counterfeiting identification device, which includes: an anti-counterfeiting identification unit, used to perform anti-counterfeiting identification on a target object based on a second image and a calibrated first image, or to perform anti-counterfeiting identification on a target object based on a first image and a calibrated second image; wherein the calibrated first image or the calibrated second image is an image calibrated by the calibration method described in the first aspect.

[0009] Fifthly, embodiments of this application provide an electronic device, including: one or more processors; and a storage device having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any embodiment of the first aspect.

[0010] In a sixth aspect, embodiments of this application provide a computer-readable medium having a computer program stored thereon that, when executed by a processor, implements the method as described in any embodiment of the first aspect.

[0011] The calibration method, anti-counterfeiting identification method, electronic device, and computer-readable medium provided in this application first control a polarization light source to emit first and second polarized light with different polarization angles at different times, and acquire the light intensity distribution information of the first and second polarized light respectively; then, based on the light intensity distribution information, calibration information is determined; when the polarization light source is again controlled to emit the first and second polarized light at different times and they are reflected by the target object and then incident on the polarization camera, the polarization camera acquires a first image and a second image, and calibrates the first or second image based on the calibration information. In the above process, by generating calibration information based on the light intensity distribution information of different polarized light before performing formal imaging, and calibrating the acquired image in real time during formal imaging using the calibration information, the interference introduced by the difference in light intensity distribution of different polarized light in the two images can be eliminated or significantly reduced, ensuring that the image differences used for subsequent anti-counterfeiting identification mainly reflect the true polarization reflection characteristics of the target object, thereby improving the accuracy of anti-counterfeiting identification based on polarization light. Attached Figure Description

[0012] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart of one embodiment of the calibration method of this application; Figure 2 This is a flowchart of one embodiment of the calibration method of this application; Figure 3 This is a schematic diagram of the polarization light source module in the calibration device of this application; Figure 4 This is a schematic diagram of the polarization light source module in the calibration device of this application; Figure 5 This is a flowchart of one embodiment of the calibration method of this application; Figure 6 This is a schematic diagram of the polarization light source module in the calibration device of this application; Figure 7 This is a schematic diagram of the structure of one embodiment of the calibration device of this application; Figure 8 This is a schematic diagram of the structure of an electronic device used to implement the embodiments of this application. Detailed Implementation

[0013] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0014] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] It should be noted that all actions involving the acquisition of signals, information, or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where the application is located, and with the authorization granted by the owner of the relevant device.

[0016] In recent years, anti-counterfeiting identification technology based on polarized light has gradually emerged. This technology uses polarized light at different angles to allow the imaging module to obtain illumination images under polarized light at different angles. By analyzing the differences in these images, it distinguishes whether the photographed object is a living person. However, after illuminating two polarized lights with different polarization angles at different times and acquiring images, the difference analysis of the two images is usually performed directly. Due to limitations in manufacturing processes and material properties, there are often differences in the uniformity of light emission between light source components used to generate different polarized light, or even between the same component in different states. This results in unexpected differences between the two acquired images, which can interfere with or even mislead subsequent image difference analysis, severely reducing the accuracy of anti-counterfeiting identification based on polarized light. This application provides a calibration method that can offset or significantly reduce the differences introduced by the uniformity of light emission in two images, thereby helping to improve the accuracy of anti-counterfeiting identification based on polarized light.

[0017] Please refer to Figure 1 This document illustrates the flow chart of one embodiment of the calibration method according to this application. The calibration method can be applied to electronic devices. The electronic device is a device capable of imaging and has image acquisition capabilities. Electronic devices may include, but are not limited to, smartphones, tablets, e-book readers, laptops, in-vehicle computers, PDAs, desktop computers, set-top boxes, smart TVs, wearable devices, smart locks, etc.

[0018] In this embodiment, the electronic device may be equipped with a polarizing light source and a polarizing camera. The polarizing light source is used to emit polarized light with different polarization angles at different times, and this polarized light is typically linearly polarized light. The timing of the emission of polarized light with different polarization angles can be preset as needed. The polarizing camera is used to receive the polarized light reflected back after it illuminates a target object from the polarizing light emitted by the polarizing light source at a certain polarization angle. That is, the polarizing camera receives polarized light with a single polarization angle, which is a specified polarization angle among the aforementioned different polarization angles. This specified polarization angle can be preset as needed.

[0019] The calibration method includes the following steps: Step 101: Control the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and obtain the light intensity distribution information of the first polarized light and the second polarized light respectively.

[0020] In this embodiment, steps 101 to 102 are typically performed before the electronic device leaves the factory. The entity executing the calibration method can first control the polarization source to emit only first polarized light and obtain the light intensity distribution information of the first polarized light; then, it can control the polarization source to emit only second polarized light and obtain the light intensity distribution information of the second polarized light.

[0021] The first and second polarized light have different polarization angles. For example, the difference in polarization angle between the first and second polarized light can be 90 degrees or close to 90 degrees. Both the first and second polarized light can be linearly polarized. Light intensity is the same as illumination intensity. Light intensity distribution information can refer to the light intensity distribution of polarized light on a specific measurement plane, which can characterize the illumination uniformity of the polarized light itself. Specifically, it can be represented as a two-dimensional image, where each pixel value represents the light intensity at that point; or it can be a discrete sequence of light intensity measurements corresponding to different regions.

[0022] In some optional implementations of this embodiment, the polarization light source includes a first light source for emitting first polarized light and a second light source for emitting second polarized light, i.e., it has two independent light sources. In this case, the first light source is first turned on and the second light source is turned off; then, the first light source is turned off and the second light source is turned on, thereby realizing time-division emission of the first polarized light and the second polarized light.

[0023] In some optional implementations of this embodiment, the polarization source itself emits both first and second polarized light, i.e., it has only one light source. For example, the polarization source can be a VCSEL (Vertical Cavity Surface Emitting Laser) or similar polarization source. In this case, the polarization source is first controlled to emit only polarized light with a first polarization angle, and then controlled to emit only polarized light with a second polarization angle, achieving time-division multiplexing of the first and second polarized light.

[0024] Step 102: Determine calibration information based on light intensity distribution information.

[0025] In this embodiment, the calibration information can characterize the difference in light intensity distribution between the first polarized light and the second polarized light. It can be a dataset, where each data point is a calibration coefficient corresponding to a sub-region or a pixel in the imaging region of the polarization camera. This calibration information is used to transform the pixel values ​​of the acquired image during subsequent imaging to eliminate or significantly reduce the difference in image brightness caused by the difference in light intensity distribution between the first polarized light and the second polarized light.

[0026] Specifically, the two light intensity distribution information obtained in step 101 can be compared and analyzed. Through point-by-point or region-by-region mathematical operations, calibration coefficients that can map one set of distribution information to another set of distribution information can be calculated. These calibration coefficients constitute the calibration information.

[0027] Step 103: When the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner and they are reflected by the target object and then enter the polarization camera, the first image and the second image are acquired by the polarization camera, and the first image or the second image is calibrated based on the calibration information.

[0028] In this embodiment, step 103 can be performed after the electronic device leaves the factory. When performing anti-counterfeiting identification through the electronic device, the polarization light source can be controlled to emit first polarized light and second polarized light in a time-division manner. The polarization camera can capture an image of the target object during the first polarization light emission stage to obtain a first image; similarly, it can capture an image of the target object during the second polarization light emission stage to obtain a second image. Theoretically, the difference between these two images should only reflect the three-dimensional characteristics of the object. However, due to the difference in light intensity distribution between the first and second polarization lights, these two images, before calibration, also contain a difference component introduced by the difference in light intensity distribution. This difference component will interfere with subsequent image difference analysis. In view of this, it is necessary to call the previously stored calibration information to calibrate one of the images to eliminate or significantly reduce the aforementioned difference component. The calibration may include, but is not limited to, multiplying or dividing the pixel values ​​of each pixel in the image with the corresponding calibration coefficients.

[0029] In some optional implementations of this embodiment, the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region of the polarization camera. When the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner again, and they are reflected by the target object and then incident on the polarization camera, the first image or the second image can first be divided into multiple image blocks that correspond one-to-one with the sub-regions in the imaging region. The rule for dividing the image blocks of the first image or the second image is the same as the rule for dividing the imaging region of the polarization camera. Then, for each image block among the multiple image blocks, the target sub-region corresponding to that image block in the imaging region is determined, and the pixel values ​​of each pixel in that image block are calibrated based on the calibration coefficients corresponding to the target sub-region.

[0030] In practice, for grayscale images, the pixel value of a pixel usually represents the brightness of that pixel, so the pixel value can be updated directly. Specifically, if the second image is used as the image to be calibrated, the pixel value of each pixel in each image block can be multiplied by the corresponding calibration coefficient to obtain the updated pixel value. If the first image is used as the image to be calibrated, the pixel value of each pixel in each image block can be divided by the corresponding calibration coefficient to obtain the updated pixel value. For color images, the same method can be used to update the brightness component of the pixel value or the value after grayscale processing, which will not be elaborated here.

[0031] By establishing a one-to-one correspondence between image blocks and calibration sub-regions, each pixel is dynamically associated with its corresponding calibration coefficient, thereby ensuring the spatial accuracy of the calibration operation. This allows the intensity difference of polarized light at any point in space with different polarization angles to be compensated by the corresponding calibration coefficient, thus eliminating or significantly reducing the systematic error components introduced by the differences in the intensity distribution of polarized light.

[0032] The method provided in the above embodiments of this application first controls a polarization source to emit first and second polarized light with different polarization angles in a time-division manner, and acquires the light intensity distribution information of the first and second polarized light respectively; then, based on the light intensity distribution information, calibration information is determined; when the polarization source is again controlled to emit the first and second polarized light in a time-division manner and they are reflected by the target object and then incident on the polarization camera, the polarization camera acquires a first image and a second image, and calibrates the first image or the second image based on the calibration information. In the above process, by generating calibration information based on the light intensity distribution information of different polarized light before performing formal imaging, and calibrating the acquired image in real time during formal imaging using the calibration information, the interference introduced by the difference in light intensity distribution of different polarized light in the two images can be eliminated or significantly reduced, ensuring that the image differences used for subsequent anti-counterfeiting identification mainly reflect the true polarization reflection characteristics of the target object, thereby improving the accuracy of anti-counterfeiting identification based on polarized light.

[0033] See Figure 2 This illustrates the flow of another embodiment of the calibration method according to this application. This calibration method can be applied to electronic devices. The electronic devices may be equipped with a polarizing light source and a polarizing camera, as described in the above embodiments, which will not be repeated here. The calibration method includes the following steps: Step 201: Control the polarization light source to emit first polarized light and second polarized light to the receiving plate in a time-division manner, and acquire the first reference image and second reference image of the receiving plate.

[0034] In this embodiment, the receiving plate is a planar medium with stable optical properties, used to receive light emitted from a polarized light source and convert it into a visible light field that can be captured by an image sensor. Its core function is to provide a standard, uniform reference plane to eliminate interference from the characteristics of the illuminated object itself on light intensity measurement, thereby purely reflecting the outgoing light intensity distribution of the light source itself. In practice, the receiving plate can include, but is not limited to, reflectors, light-diffusing plates, etc.

[0035] In this embodiment, the polarization light source is first controlled to emit first polarized light. At this time, an imaging device captures an image of the receiving plate, obtaining a digital image frame which is stored as a first reference image. Subsequently, the first polarization light is turned off, and the second polarization light is turned on. With the receiving plate position and camera parameters remaining completely unchanged, a second image frame is captured and stored as a second reference image. The imaging device can be the aforementioned polarization camera, or it can be a camera configured within the aforementioned electronic device or another camera independent of the aforementioned electronic device, which can be referred to as a calibration camera; no limitation is made here. The calibration camera does not require a polarizer; its optical design makes it insensitive to the polarization state of the incident light. Its main function is to accurately measure the spatial distribution of light intensity. Its resolution and field of view must meet the calibration measurement requirements; that is, its imaging area must include the imaging area of ​​the polarization camera.

[0036] In some optional implementations of this embodiment, the receiving plate can be a reflector. The first reference image and the second reference image can be acquired by the polarization camera or the calibration camera described above. When acquired by the calibration camera, the calibration camera and the polarization light source can be located on the same side of the reflector, and the imaging area of ​​the calibration camera includes the imaging area of ​​the polarization camera. Light emitted by the polarization light source illuminates the surface of the reflector, and after reflection, the polarization camera or the calibration camera captures the illuminated image of the reflector. See also Figure 3 The reflector is shown as 301, the polarization light source is shown as 302, and the polarization camera or calibration information is shown as 303.

[0037] The reflector can include, but is not limited to, diffuse reflectors, such as spectral-grade white boards, frosted white acrylic sheets, and matte white ceramic sheets. A diffuse reflector is an optical element with a specially treated surface, such as being sprayed with high-reflectivity diffuse reflective materials like barium sulfate or magnesium oxide, or treated with frosting or microparticle coating processes. The optical characteristic of a diffuse reflector is that when light shines on its surface, Lambertian diffuse reflection occurs primarily, meaning the intensity of the incident light reflected is approximately equal in all directions, and it essentially does not form specular reflection spots. This allows it to uniformly reflect the incident polarized light, forming a secondary luminous surface whose brightness distribution is determined only by the incident light itself and has little relation to the viewing angle. When the receiving plate is a reflector, its function is to convert the spatially distributed light intensity information emitted from the polarized light source into a uniformly diffused two-dimensional brightness field image that is easy for a camera to capture, free from specular interference. The camera captures the diffuse reflection brightness of the reflector itself, rather than the direct image of the light source. This avoids problems such as overexposure, halo, or uneven imaging that may occur when the camera sensor directly captures the light source, and can record the light intensity distribution of the light source more realistically and stably.

[0038] In some optional implementations of this embodiment, the receiving plate can be a light-diffusing plate. The first and second reference images are acquired by a calibration camera. The imaging area of ​​the calibration camera includes the imaging area of ​​the polarization camera. The calibration camera and the polarization light source are located on different sides of the light-diffusing plate; specifically, the calibration camera is located on the light-emitting side of the light-diffusing plate, and the polarization light source is located on the light-incident side. The light emitted by the light source is transmitted through the light-diffusing plate, which diffuses it evenly before the light-emitting surface is directly photographed by the calibration camera on the other side. The light source, the light-diffusing plate, and the calibration camera are approximately on the same straight line. The distance from the calibration camera to the light-diffusing plate can be preset based on the field of view of the polarization camera, the angle of the light from the polarization light source, and the distance from the polarization light source to the light-diffusing plate. See also... Figure 4 The light homogenizer is shown as 401, the polarizing light source is shown as 402, and the calibration camera is shown as 403.

[0039] A light homogenizer, also known as a diffuser or transmission diffuser, is typically made of transparent substrates such as glass, polymethyl methacrylate, or polycarbonate, doped with scattering microparticles. Its core optical characteristic is that when light passes through it, it undergoes strong scattering, creating a Lambertian luminous surface with uniform brightness distribution near the normal direction of the exit surface. When the receiving plate is a light homogenizer, its function is to scatter the polarized light emitted from a polarized source through transmission, creating a softer exit light field with significantly improved spatial uniformity on the other side of the plate. The camera captures the exit surface of the light homogenizer, obtaining an image of the homogenized light intensity distribution.

[0040] Step 202: Divide the imaging area of ​​the polarization camera in the first reference image and the second reference image into multiple sub-regions, and determine the brightness value of each sub-region.

[0041] In this embodiment, if the first reference image and the second reference image are acquired by a polarization camera, then the first reference image and the second reference image constitute the imaging area of ​​the polarization camera. If the first reference image and the second reference image are acquired by a calibration camera, then the first reference image and the second reference image contain the imaging area of ​​the polarization camera. Specifically, firstly, according to pre-calibrated or designed parameters, imaging areas that completely match the actual working field of view of the polarization camera are located on the first reference image and the second reference image, respectively. Then, the same grid partitioning algorithm is used to divide this area into multiple sub-regions. For example, a rectangular grid of M rows × N columns, where M and N are both positive integers. Afterwards, for each sub-region, a statistical measure of the brightness values ​​of all pixels within it is calculated and used as the brightness value of that sub-region. The aforementioned statistical measure may include, but is not limited to, the arithmetic mean.

[0042] It should be noted that in digital image processing, brightness value refers to the quantized value of visual lightness or darkness. For grayscale images, the pixel value is the brightness value; for color images, the brightness value can refer to the brightness component of the pixel value or the value after grayscale processing.

[0043] Step 203: Based on the brightness values ​​of each sub-region in the imaging region of the first reference image, determine the light intensity distribution information of the first polarized light, and based on the brightness values ​​of each sub-region in the imaging region of the second reference image, determine the light intensity distribution information of the second polarized light.

[0044] It is understandable that the brightness value of a certain area in an image is positively correlated with the light intensity illuminating that area; that is, the higher the brightness value, the higher the light intensity. Therefore, the brightness values ​​of each sub-region in the imaging region of the polarization camera in the first reference image can characterize the light intensity distribution of the first polarized light. The brightness values ​​of each sub-region in the imaging region of the polarization camera in the first reference image can be summarized to obtain the light intensity distribution information of the first polarized light. In other words, the light intensity distribution information of the first polarized light is the set of brightness values ​​of each sub-region in the imaging region of the polarization camera in the first reference image.

[0045] Similarly, the brightness values ​​of each sub-region in the imaging region of the polarization camera in the second reference image can characterize the intensity distribution of the second polarized light. The brightness values ​​of each sub-region in the imaging region of the polarization camera in the second reference image can be summarized to obtain the intensity distribution information of the second polarized light. That is, the intensity distribution information of the second polarized light is the set of brightness values ​​of each sub-region in the imaging region of the polarization camera in the second reference image.

[0046] Step 204: Determine calibration information based on light intensity distribution information.

[0047] In this embodiment, different methods can be used to determine the calibration information depending on the imaging device used to capture the first and second reference images. The calibration information may include calibration coefficients corresponding to each sub-region within the imaging region. Each calibration coefficient is a value calculated for each sub-region within the imaging region, used to align the brightness within that sub-region to a consistent level under both the first and second polarized light.

[0048] In some alternative implementations, the receiving plate is a reflector, and the first and second reference images are acquired by a polarization camera. Based on this, calibration information can be determined through the following steps: The first step is to determine the ratio of the brightness value of that sub-region in the first reference image to the brightness value of that sub-region in the second reference image for each sub-region in the imaging region. For example, there are 7×7 sub-regions, totaling 49. For a certain sub-region i, the brightness value of sub-region i in the first reference image can be L1_i, and the brightness value of sub-region i in the second reference image can be L2_i. Then, L1_i / L2_i can be calculated and denoted as R_i. i is an integer greater than or equal to 1 and less than or equal to 49.

[0049] The second step involves selecting a reference sub-region within the imaging region. The ratio corresponding to this reference sub-region is used as the reference value. Based on the ratios of each sub-region within the imaging region and the reference value, the calibration coefficients for each sub-region within the imaging region are determined. The reference sub-region can be set as needed, typically selecting a region with stable optical performance, high signal-to-noise ratio, and representative of typical lighting conditions, such as the center region of the light spot. Specifically, the reference value can be denoted as R_ref. For a given sub-region i, the reference value R_ref can be divided by its corresponding ratio R_i to obtain the calibration coefficient k_i = R_ref / R_i.

[0050] It is understandable that a polarization camera is used to receive polarized light emitted from a polarization source at a certain polarization angle, which is reflected back after illuminating a target object. That is, the polarization camera receives polarized light at a single polarization angle, specifically one of first polarization light and second polarization light. Taking the polarization camera receiving first polarization light as an example, the brightness value of each sub-region under first polarization light should theoretically be much greater than the brightness value of each sub-region under second polarization light; therefore, the ratio of the two should not be directly used as the calibration coefficient. By selecting a reference sub-region and using the ratio of the brightness value of the reference sub-region in the first reference image to the brightness value of the reference sub-region in the second reference image as the reference value, and then calculating Ki = R_ref / R_i to obtain the calibration coefficient for each region, the calibration objective for all regions can be adjusted from eliminating absolute brightness differences to making the proportional relationship of brightness values ​​in the same region under different polarization lights the same. This effectively isolates the influence of the local depolarization characteristics of the reflector and the angle between the polarizer and the polarizer of the polarization camera, so that the final calibration coefficient only reflects the spatial intensity distribution difference between the two light sources themselves. Meanwhile, by using the polarization camera itself to acquire reference images under different polarizations, the cost and space of an additional calibration camera are eliminated, achieving hardware reuse and reducing calibration costs.

[0051] In some alternative implementations, the receiving plate is a reflector, and the first and second reference images are acquired by a calibration camera, with the calibration camera and the polarizing light source located on the same side of the reflector; alternatively, the receiving plate is a homogenizer, and the first and second reference images are acquired by the calibration camera, with the calibration camera and the polarizing light source located on different sides of the homogenizer. Based on this, for each sub-region in the imaging area, the ratio of the brightness value of that sub-region in the first reference image to the brightness value of that sub-region in the second reference image is determined as the calibration coefficient corresponding to that sub-region.

[0052] By using a calibration camera to acquire reference images under different polarizations, the influence of the local depolarization characteristics of the reflector and the angle between the polarizer and the polarizer of the polarizer, which is faced when using a polarization camera for calibration, is avoided. This makes the calculation of calibration coefficients simpler and improves the efficiency of calibration information generation.

[0053] Step 205: When the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner and they are reflected by the target object and then incident on the polarization camera, the first image and the second image are acquired by the polarization camera, and the first image or the second image is calibrated based on the calibration information.

[0054] Step 205 of this embodiment can be found in [reference needed]. Figure 1 Step 103 of the corresponding embodiment will not be described again here.

[0055] The method provided in the above embodiments of this application acquires the light intensity distribution information of the first and second polarized light by employing image acquisition and region segmentation analysis. This achieves a refined and quantitative description of the light intensity distribution of the light source, rather than a coarse overall estimate, thus laying a solid data foundation for generating high-precision calibration information. Simultaneously, it compresses the data units that require independent calculation and storage of calibration parameters from a massive number of pixels to a limited number of sub-regions, reducing data processing complexity and computational load, and improving the efficiency of generating light intensity distribution information and calibration information.

[0056] See Figure 5 This illustrates the flow of another embodiment of the calibration method according to this application. This calibration method can be applied to electronic devices. The electronic devices may be equipped with a polarizing light source and a polarizing camera, as described in the above embodiments, which will not be repeated here. The calibration method includes the following steps: Step 501: Control the polarization light source to emit first polarized light and second polarized light in a time-division manner, and obtain the first light intensity measurement value when the first polarized light is emitted and the second light intensity measurement value when the second polarized light is emitted through a photodiode array located in a two-dimensional plane.

[0057] In this embodiment, see Figure 6 The photodiode array is shown as reference numeral 601, and the polarization light source is shown as reference numeral 602. A photodiode array is a collection of one-dimensional or two-dimensional sensors composed of multiple photodiodes arranged according to specific rules. A photodiode is a photoelectric sensor that converts incident light signals into electrical signals. Each photodiode acts as an independent photosensitive unit, and the amplitude of its output electrical signal is proportional to the light intensity illuminating its photosensitive surface. In this embodiment, the photodiode array can be used to replace a camera to directly acquire spatial distribution data of the light intensity of the first polarized light and the second polarized light.

[0058] The center points of the photosensitive surfaces of all photosensitive units in the photodiode array are distributed on the same two-dimensional plane. The position of the photodiode array can be preset according to the field of view of the polarization camera, the angle of the polarization light source, and the distance from the polarization light source to the homogenizing plate. Each photodiode in the photodiode array corresponds to a sub-region of the imaging area of ​​the polarization camera, specifically the center of a sub-region, which is not limited here. Therefore, it can be ensured that the calibration parameters determined based on the light intensity measurement can be accurately applied to the pixel values ​​of the corresponding sub-region in the image captured by the polarization camera.

[0059] The first and second light intensity measurements refer to the quantized digital values ​​of the electrical signals output by each photodiode in the photodiode array after signal conditioning, when the first and second polarized light are emitted separately. These values ​​directly correspond to the light intensity at the location of that photodiode.

[0060] Step 502: Determine the light intensity distribution information of the first polarized light based on the first light intensity measurement value, and determine the light intensity distribution information of the second polarized light based on the second light intensity measurement value.

[0061] In this embodiment, the intensity distribution information of the first polarized light can be obtained by summing up the first light intensity measurements. Similarly, the intensity distribution information of the second polarized light can be obtained by summing up the second light intensity measurements.

[0062] Step 503: Determine calibration information based on light intensity distribution information.

[0063] In this embodiment, for each sub-region of the imaging region, the ratio of the first light intensity measurement value to the second light intensity measurement value corresponding to the sub-region can be determined as the calibration coefficient corresponding to the sub-region.

[0064] Step 504: When the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner and they are reflected by the target object and then incident on the polarization camera, the first image and the second image are acquired by the polarization camera, and the first image or the second image is calibrated based on the calibration information.

[0065] Step 504 of this embodiment can be found in [reference needed]. Figure 1 Step 103 of the corresponding embodiment will not be described again here.

[0066] The method provided in the above embodiments of this application uses a photodiode array as a sensor, with each unit directly outputting an electrical signal proportional to the light intensity. This eliminates the need for complex exposure control, pixel scanning readout, and image processing steps when capturing reference images with an imaging device to determine light intensity distribution information. This greatly shortens the time required to acquire light intensity distribution information and improves the efficiency of generating calibration information.

[0067] Further reference Figure 7 As an implementation of the methods shown in the above figures, this application provides an embodiment of a calibration device, which is similar to... Figure 1 Corresponding to the method embodiments shown, this device can be specifically applied to various electronic devices.

[0068] like Figure 7As shown, the calibration device 700 of this embodiment includes: an acquisition unit 701, used to control the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and to acquire light intensity distribution information of the first polarized light and the second polarized light respectively; a determination unit 702, used to determine calibration information based on the light intensity distribution information, the calibration information being used to characterize the difference in light intensity distribution between the first polarized light and the second polarized light; and a calibration unit 703, used to acquire a first image and a second image through the polarization camera when the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner again and they are reflected by the target object and then incident on the polarization camera respectively, and to calibrate the first image or the second image based on the calibration information.

[0069] In some optional implementations of this embodiment, the acquisition unit 701 is further configured to: control the polarization light source to emit the first polarized light and the second polarized light to the receiving plate in a time-division manner, and acquire the first reference image and the second reference image of the receiving plate; divide the imaging area of ​​the polarization camera in the first reference image and the second reference image into multiple sub-regions respectively, and determine the brightness value of each sub-region; determine the light intensity distribution information of the first polarized light based on the brightness value of each sub-region in the imaging area of ​​the first reference image, and determine the light intensity distribution information of the second polarized light based on the brightness value of each sub-region in the imaging area of ​​the second reference image.

[0070] In some optional implementations of this embodiment, the receiving plate is a reflector, and the first reference image and the second reference image are acquired by the polarization camera; the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; the determining unit 702 is further configured to: for each sub-region in the imaging region, determine the ratio of the brightness value of the sub-region in the first reference image to the brightness value of the sub-region in the second reference image; select a reference sub-region in the imaging region, use the ratio corresponding to the reference sub-region as a reference value, and determine the calibration coefficients corresponding to each sub-region in the imaging region based on the ratios corresponding to each sub-region in the imaging region and the reference value.

[0071] In some optional implementations of this embodiment, the receiving plate is a reflector, the first reference image and the second reference image are acquired by a calibration camera, and the calibration camera and the polarizing light source are located on the same side of the reflector; or, the receiving plate is a homogenizing plate, the first reference image and the second reference image are acquired by the calibration camera, and the calibration camera and the polarizing light source are located on different sides of the homogenizing plate; the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; the determining unit 702 is further configured to: for each sub-region in the imaging region, determine the ratio of the brightness value of the sub-region in the first reference image to the brightness value of the sub-region in the second reference image as the calibration coefficient corresponding to the sub-region.

[0072] In some optional implementations of this embodiment, the acquisition unit 701 is further configured to: control the polarization light source to emit the first polarized light and the second polarized light in a time-division manner, and acquire the first light intensity measurement value when the first polarized light is emitted and the second light intensity measurement value when the second polarized light is emitted through a photodiode array located in a two-dimensional plane, wherein each photodiode in the photodiode array corresponds to a sub-region in the imaging area of ​​the polarization camera; determine the light intensity distribution information of the first polarized light based on the first light intensity measurement value, and determine the light intensity distribution information of the second polarized light based on the second light intensity measurement value.

[0073] In some optional implementations of this embodiment, the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; the determining unit 702 is further configured to: for each sub-region in the imaging region, determine the ratio of the first light intensity measurement value to the second light intensity measurement value corresponding to the sub-region as the calibration coefficient corresponding to the sub-region.

[0074] In some optional implementations of this embodiment, the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region of the polarization camera; the calibration unit 703 is further configured to: divide the first image or the second image into a plurality of image blocks that correspond one-to-one with the sub-regions in the imaging region; for each of the plurality of image blocks, determine a target sub-region in the imaging region that corresponds to the image block, and calibrate the pixel values ​​of each pixel in the image block based on the calibration coefficients corresponding to the target sub-region.

[0075] In some optional implementations of this embodiment, the polarization light source includes a first light source for emitting the first polarized light and a second light source for emitting the second polarized light; or, the polarization light source itself emits the first polarized light and the second polarized light.

[0076] The apparatus provided in the above embodiments of this application first controls a polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquires the light intensity distribution information of the first polarized light and the second polarized light respectively; then, based on the light intensity distribution information, calibration information is determined; when the polarization light source is again controlled to emit first polarized light and second polarized light in a time-division manner and they are reflected by the target object and then incident on the polarization camera, a first image and a second image are acquired by the polarization camera, and the first image or the second image is calibrated based on the calibration information. In the above process, by generating calibration information based on the light intensity distribution information of different polarized light before performing formal imaging, and calibrating the acquired image in real time during formal imaging using the calibration information, the interference introduced by the difference in light intensity distribution of different polarized light in the two images can be eliminated or significantly reduced, ensuring that the image differences used for subsequent anti-counterfeiting identification mainly reflect the true polarization reflection characteristics of the target object, thereby improving the accuracy of anti-counterfeiting identification based on polarized light.

[0077] Furthermore, this application also provides an anti-counterfeiting identification method. This anti-counterfeiting identification method can be applied to electronic devices. The electronic device is a device capable of imaging and has image acquisition capabilities. The electronic device may include, but is not limited to, smartphones, tablets, e-book readers, laptops, in-vehicle computers, handheld computers, desktop computers, set-top boxes, smart TVs, wearable devices, smart locks, etc. The method includes: Anti-counterfeiting identification of the target object is performed based on the second image and the calibrated first image, or anti-counterfeiting identification of the target object is performed based on the first image and the calibrated second image; wherein the calibrated first image or the calibrated second image is an image calibrated by the calibration method in the above embodiments.

[0078] Specifically, when performing anti-counterfeiting identification using electronic devices, a polarized light source can be controlled to emit first and second polarized light in a time-division manner. A polarization camera can capture an image of the target object during the first polarized light emission phase to obtain the first image; similarly, capturing an image of the target object during the second polarized light emission phase yields the second image. Theoretically, the difference between these two images should only reflect the three-dimensional characteristics of the object. However, due to the difference in light intensity distribution between the first and second polarized lights, these two images, before calibration, also contain a difference component introduced by the difference in light intensity distribution. This difference component can interfere with subsequent image difference analysis. Therefore, one of the images can be calibrated to obtain either a calibrated first image or a calibrated second image. This helps to eliminate or significantly reduce the interference introduced by the difference in light intensity distribution between the two polarized lights, ensuring that the image differences used for anti-counterfeiting identification primarily reflect the true polarization and reflection characteristics of the target object.

[0079] In this embodiment, anti-counterfeiting identification may include liveness detection to determine whether the target object is a living entity. When performing liveness detection on the target object, a difference image can be first obtained between a first image and a calibrated second image, or a difference image can be obtained between the second image and a calibrated first image. The difference image is obtained by subtracting the pixel value matrices of the two images and is used to characterize the difference between the two images. When the target object is a living entity, due to the different morphologies and materials of different parts of the target object having different depolarization capabilities for polarized light, the reflected light from different parts carries different polarization information, thus the difference image may have obvious liveness features. Conversely, when the target object is not a living entity, since such attack materials are two-dimensional planes, the difference image does not have obvious liveness features. Therefore, after obtaining the difference image, it is possible to determine whether the target object is a living entity based on the difference image. In practice, the difference image can be input into a liveness detection model to obtain liveness detection results. The liveness detection model can be used for liveness identification to detect whether the target object is a living or non-living entity. The liveness detection model can be pre-trained on a convolutional neural network based on machine learning algorithms and deployed in the aforementioned electronic devices. Using the liveness detection model, liveness detection can be performed quickly and accurately, yielding accurate liveness detection results.

[0080] It should be noted that, depending on the needs, anti-counterfeiting identification may also include biometric identification to determine the identity of the target item. Biometric identification can be performed before or after liveness detection, or it can be performed simultaneously; this is not limited here.

[0081] As an implementation of the methods shown in the above figures, this application also provides an anti-counterfeiting identification device. This device corresponds to the anti-counterfeiting identification method in the above embodiments, and can be specifically applied to various electronic devices. The device includes: an anti-counterfeiting identification unit, used to perform anti-counterfeiting identification on a target object based on a second image and a calibrated first image, or, based on a first image and a calibrated second image; wherein the calibrated first image or the calibrated second image is an image calibrated using the calibration method described in the above embodiments.

[0082] By calibrating one of the images used for anti-counterfeiting identification, interference introduced by the difference in light intensity distribution of different polarized light in the two images can be eliminated or significantly reduced. This ensures that the differences in the images used for anti-counterfeiting identification mainly reflect the true polarization and reflection characteristics of the target object, thereby improving the accuracy of anti-counterfeiting identification based on polarized light.

[0083] The following is for reference. Figure 8 It shows a schematic diagram of the structure of an electronic device used to implement some embodiments of this application. Figure 8 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this application.

[0084] like Figure 8 As shown, the electronic device 800 may include a processing device (e.g., a central processing unit, a graphics processor, etc.) 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage device 808 into a random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the electronic device 800. The processing device 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0085] Typically, the following devices can be connected to I / O interface 805: input devices 806 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 807 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 808 including, for example, disks, hard disks, etc.; and communication devices 809. Communication device 809 allows electronic device 800 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 8 An electronic device 800 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 8 Each box shown can represent a device or multiple devices as needed.

[0086] In particular, according to some embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, some embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 809, or installed from a storage device 808, or installed from a ROM 802. When the computer program is executed by the processing device 801, it performs the functions defined in the methods of some embodiments of this application.

[0087] It should be noted that the computer-readable medium described in some embodiments of this application may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In some embodiments of this application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In some embodiments of this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0088] In some implementations, clients and servers can communicate using any currently known or future-developed network protocol such as HTTP (Hypertext Transfer Protocol) and can interconnect with digital data communication (e.g., communication networks) of any form or medium. Examples of communication networks include local area networks (“LANs”), wide area networks (“WANs”), the Internet (e.g., the Internet of Things), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks), as well as any currently known or future-developed networks.

[0089] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more programs that, when executed by the electronic device, cause the electronic device to: control a polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquire light intensity distribution information of the first polarized light and the second polarized light respectively; determine calibration information based on the light intensity distribution information, the calibration information being used to characterize the difference in light intensity distribution between the first polarized light and the second polarized light; and when the polarization light source is again controlled to emit the first polarized light and the second polarized light in a time-division manner and they are reflected by the target object and then incident on a polarization camera, the polarization camera acquires a first image and a second image, and calibrates the first image or the second image based on the calibration information.

[0090] Computer program code for performing operations of some embodiments of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++; and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, or it can be connected to an external computer (e.g., via the Internet using an Internet service provider), including local area networks (LANs) or wide area networks (WANs).

[0091] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0092] The units described in some embodiments of this application can be implemented in software or hardware. The described units can also be housed in a processor; for example, a processor may be described as including a first determining unit, a second determining unit, a selecting unit, and a third determining unit. The names of these units do not necessarily limit the specific unit itself.

[0093] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), and so on.

[0094] The above description is merely a selection of preferred embodiments of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this application.

Claims

1. A calibration method, characterized in that, Applied to an electronic device equipped with a polarizing light source and a polarizing camera, the method includes: The polarization light source is controlled to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and the light intensity distribution information of the first polarized light and the second polarized light is obtained respectively; Based on the light intensity distribution information, calibration information is determined, which is used to characterize the difference in light intensity distribution between the first polarized light and the second polarized light. When the polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner again, and they are reflected by the target object and then enter the polarization camera, the polarization camera acquires the first image and the second image, and calibrates the first image or the second image based on the calibration information.

2. The method according to claim 1, characterized in that, The method of controlling the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquiring the light intensity distribution information of the first polarized light and the second polarized light respectively, includes: The polarization light source is controlled to emit the first polarized light and the second polarized light to the receiving plate in a time-division manner, and the first reference image and the second reference image of the receiving plate are acquired. The imaging areas of the polarization camera in the first reference image and the second reference image are divided into multiple sub-regions, and the brightness value of each sub-region is determined. Based on the brightness values ​​of each sub-region in the imaging region of the first reference image, the light intensity distribution information of the first polarized light is determined, and based on the brightness values ​​of each sub-region in the imaging region of the second reference image, the light intensity distribution information of the second polarized light is determined.

3. The method according to claim 2, characterized in that, The receiving plate is a reflector, and the first reference image and the second reference image are acquired by the polarization camera; the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; determining the calibration information based on the light intensity distribution information includes: For each sub-region in the imaging region, determine the ratio of the brightness value of that sub-region in the first reference image to the brightness value of that sub-region in the second reference image; A reference sub-region is selected in the imaging region, and the ratio corresponding to the reference sub-region is used as the reference value. Based on the ratio corresponding to each sub-region in the imaging region and the reference value, the calibration coefficient corresponding to each sub-region in the imaging region is determined.

4. The method according to claim 2, characterized in that, The receiving plate is a reflector, and the first reference image and the second reference image are acquired by a calibration camera, with the calibration camera and the polarizing light source located on the same side of the reflector; or, the receiving plate is a homogenizer, and the first reference image and the second reference image are acquired by the calibration camera, with the calibration camera and the polarizing light source located on different sides of the homogenizer; the calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; determining the calibration information based on the light intensity distribution information includes: For each sub-region in the imaging region, the ratio of the brightness value of the sub-region in the first reference image to the brightness value of the sub-region in the second reference image is determined as the calibration coefficient corresponding to the sub-region.

5. The method according to claim 1, characterized in that, The method of controlling the polarization light source to emit first polarized light and second polarized light with different polarization angles in a time-division manner, and acquiring the light intensity distribution information of the first polarized light and the second polarized light respectively, includes: The polarization light source is controlled to emit the first polarized light and the second polarized light in a time-division manner, and the first light intensity measurement value when the first polarized light is emitted and the second light intensity measurement value when the second polarized light is emitted are obtained by a photodiode array located in a two-dimensional plane. Each photodiode in the photodiode array corresponds to a sub-region in the imaging area of ​​the polarization camera. The light intensity distribution information of the first polarized light is determined based on the first light intensity measurement value, and the light intensity distribution information of the second polarized light is determined based on the second light intensity measurement value.

6. The method according to claim 5, characterized in that, The calibration information includes calibration coefficients corresponding to each sub-region in the imaging region; determining the calibration information based on the light intensity distribution information includes: For each sub-region in the imaging region, the ratio of the first light intensity measurement value to the second light intensity measurement value corresponding to the sub-region is determined as the calibration coefficient corresponding to the sub-region.

7. The method according to claim 1, characterized in that, The calibration information includes calibration coefficients corresponding to each sub-region in the imaging region of the polarization camera; the calibration of the first image or the second image based on the calibration information includes: The first image or the second image is divided into multiple image blocks that correspond one-to-one with the sub-regions in the imaging region; For each of the plurality of image blocks, a target sub-region corresponding to the image block is determined in the imaging region, and the pixel values ​​of each pixel in the image block are calibrated based on the calibration coefficient corresponding to the target sub-region.

8. The method according to claim 1, characterized in that, The polarization light source includes a first light source for emitting the first polarized light and a second light source for emitting the second polarized light; or, the polarization light source itself emits the first polarized light and the second polarized light.

9. A method for anti-counterfeiting identification, characterized in that, The method includes: Anti-counterfeiting identification of the target object is performed based on the second image and the calibrated first image, or anti-counterfeiting identification of the target object is performed based on the first image and the calibrated second image. Wherein, the calibrated first image or the calibrated second image is an image calibrated by the calibration method according to any one of claims 1-8.

10. An electronic device, characterized in that, include: A processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the method as claimed in any one of claims 1-9.

11. A computer-readable medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-9.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1-9.

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