Glare identification and inhibition method and system

Abstract

The invention provides a glare identification and suppression method and system, and belongs to the field of optical control. The method comprises the following steps: constructing a polarization characteristic database based on different light sources; collecting a view field image and the light intensity and the polarization state of ambient light in a view field range; setting a light intensity threshold value, judging the light intensity of the collected current ambient light, preprocessing the light intensity and polarization state data when the light intensity is greater than the light intensity threshold value, and carrying out glare feature recognition, space-polarization correlation mapping, binary glare distribution matrix generation and modulation instruction generation on the ambient light based on the polarization feature database; converting the glare distribution matrix into a corresponding analog voltage matrix; and converting the modulation instruction into a corresponding driving voltage, applying the corresponding driving voltage to a corresponding pixel unit in the analog voltage matrix, realizing selective polarization state modulation of glare pixel points in the incident light, and outputting the emergent light of which the glare is inhibited. According to the invention, the glare suppression effect is improved.

Description

Technical Field

[0001] This invention belongs to the field of optical control, specifically relating to a glare recognition and suppression method and system. Background Technology

[0002] When the eyes observe objects, glare can occur when the brightness distribution in the field of vision is unsuitable or there is extreme contrast. This can cause visual discomfort, reduce the visibility of objects, and even lead to temporary blurred vision or eye strain. Glare formation is related to the brightness of the light source, the reflection angle, and the adaptability of the human eye. It is common in scenarios such as driving and outdoor sports and poses a safety hazard. For example, while driving, drivers are exposed to strong light interference from various sources, such as headlights of oncoming vehicles, low-angle sunlight, and reflected light from wet road surfaces, thus creating glare. This glare is not only extremely bright but also highly polarized, seriously affecting driving safety.

[0003] Existing technologies for glare prevention include optimizing lamp design and using polarized lenses. Polarized lenses, which act directly on the eyes, are therefore widely used. However, existing polarized lens designs have the following problems: they cannot distinguish between harmful glare and beneficial ambient light, resulting in a "one-size-fits-all" approach to glare and reducing overall visibility; they cannot identify and respond to multiple glare sources with different polarization characteristics; their response speed is slow, making them unable to cope with dynamically changing driving environments; they lack the ability to adapt to changes in spatial factors and spatial positioning, unable to distinguish the specific location of glare originating from the field of vision (upper left corner, front, lower right corner), and can only perform global processing based on the entire field of vision; while reducing glare, they also block useful polarization information. When the polarization angle of the lens coincides with the polarization angle of the light, the screen may become completely black and unreadable, making electronic displays unreadable. Due to these numerous problems, polarized lenses have poor anti-glare effects, failing to effectively suppress glare and still posing significant safety hazards. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a glare identification and suppression method and system. By combining data from two perspectives, light intensity and polarization state, and combining with a database, the glare source and type are identified and located, realizing the leap from "perceiving glare" to "perceiving where the glare is". Based on the identification of glare, an independently addressable liquid crystal cell array is used. By applying voltage to specific pixel units, the polarization direction of light in a specific spatial area is selectively and dynamically changed, thereby achieving precise suppression of glare, improving the glare prevention effect while ensuring the illumination of the original light source.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a glare recognition and suppression method, the method comprising the following steps:

[0007] Step S1: Construct a polarization feature database based on different light sources;

[0008] Step S2: Acquire the field-of-view image, as well as the light intensity and polarization state of the ambient light within the field of view;

[0009] Step S3: Set a light intensity threshold and judge the light intensity of the current ambient light collected. If the light intensity is greater than the light intensity threshold, proceed to step S4; if the light intensity is less than or equal to the light intensity threshold, return to step S2.

[0010] Step S4: Preprocess the light intensity and polarization state data;

[0011] Step S5: Based on the preprocessed polarization state data, perform glare feature recognition on ambient light using a polarization feature database; perform spatial-polarization correlation mapping based on the field of view image to generate a binary glare distribution matrix.

[0012] Step S6: Analyze the binarized glare distribution matrix and generate modulation instructions based on the pixels in the matrix that require glare suppression.

[0013] Step S7: Convert the glare distribution matrix into the corresponding analog voltage matrix; convert the modulation command into the corresponding driving voltage; apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix to achieve selective polarization state modulation of the glare pixels in the incident light; selectively filter the elliptically polarized and linearly polarized light components in the glare; and output the glare-suppressed outgoing light.

[0014] In a preferred embodiment of the present invention, the polarization feature database stores polarization fingerprints of typical glare sources, and the polarization fingerprints are inherent and stable polarization features of the preset glare sources, which can be used to accurately identify the type of glare.

[0015] In a preferred embodiment of the present invention, the polarization state includes the polarization angle and the degree of polarization of light, wherein the polarization angle is the angle of the polarization direction, and the degree of polarization is the ratio of the intensity of the polarized part in the light beam to the total intensity, and the value ranges from 0 to 1; where 0 represents natural light and 1 represents fully polarized light.

[0016] In a preferred embodiment of the present invention, the light intensity threshold is 10000 Lux.

[0017] In a preferred embodiment of the present invention, the preprocessing in step S4 includes eliminating noise, errors, and interference; wherein...

[0018] When eliminating noise, the Kalman filter algorithm is used to weight and fuse the polarization angle measurement value of each pixel in the current frame with the predicted value of the previous frame, which effectively suppresses instantaneous and random polarization noise and obtains a smooth and reliable polarization angle data stream.

[0019] To eliminate interference, perform strong light correction. Use gamma correction to obtain the sensor's response curve in advance and build a lookup table (LUT). Then, by querying the LUT, quickly obtain the true light intensity value after linearization correction.

[0020] In a preferred embodiment of the present invention, the spatial-polarization correlation mapping in step S5 is presented as a correspondence database or matrix, which associates the X,Y coordinates of each specific location in the field of view with the polarization angle θ of the main polarized light detected at that location.

[0021] In a preferred embodiment of the present invention, when converting the glare distribution matrix into the corresponding analog voltage matrix in step S7, each 0 or 1 in the binarized matrix is ​​converted into the corresponding analog voltage; for the point where the "1" value needs to be suppressed, a specific driving voltage V_on is output; for the point where the "0" value is normal, V_off is output.

[0022] Secondly, embodiments of the present invention also provide a glare recognition and suppression system, the system comprising: a polarization feature database, a light intensity sensor, a polarization direction sensor, a light intensity activation module, a preprocessing module, a polarization recognition engine, a spatial polarization mapping module, and a spatial light modulator; wherein,

[0023] The polarization feature database is used to store polarization fingerprints of typical glare light sources;

[0024] The light intensity sensor is used to measure the light intensity of ambient light within the field of view;

[0025] The polarization direction sensor is used to acquire the field of view image and the polarization state of ambient light within the field of view;

[0026] The light intensity activation module is used to set the light intensity threshold and judge the light intensity of the current ambient light collected. When the light intensity is greater than the light intensity threshold, polarization suppression is triggered and the preprocessing module is activated.

[0027] The preprocessing module is used to preprocess the light intensity and polarization state data;

[0028] The polarization recognition engine is used to identify glare features of ambient light based on the preprocessed polarization state data and a polarization feature database.

[0029] The spatial polarization mapping module is used to perform spatial-polarization correlation mapping based on the field of view image to generate a binary glare distribution matrix.

[0030] The spatial light modulator is used to analyze the binarized glare distribution matrix, generate modulation instructions based on the pixels in the matrix that need glare suppression, convert the glare distribution matrix into a corresponding analog voltage matrix, convert the modulation instructions into a corresponding driving voltage, apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix, achieve selective polarization state modulation of the glare pixels in the incident light, selectively filter the elliptically polarized and linearly polarized light components in the glare, and output the glare-suppressed outgoing light.

[0031] In a preferred embodiment of the present invention, the spatial light modulator includes coplanar electrodes and an electroactive layer; wherein, in the coplanar electrodes, the first and second transparent electrodes are coplanarly fabricated on the same substrate in the form of alternating conductive strips, and the required transverse electric field is generated by applying an alternating electric field between adjacent strips; the electroactive layer is composed of a material containing nematic liquid crystal and dichroic dye, and in the off state without electric field, the liquid crystal can exhibit a twisted nematic arrangement; the polarization characteristics are dynamically changed by controlling the orientation of the liquid crystal and dichroic dye molecules by the electric field; in the off state, light with a specific polarization component can be output for unpolarized incident light, and its polarization ratio is more than 70%; in the on state, the polarization state is significantly changed.

[0032] In a preferred embodiment of the present invention, the spatial light modulator is composed of an array containing a plurality of independently controllable liquid crystal modulation units;

[0033] The structure of the liquid crystal modulation unit includes: a base layer, an electrode layer, and a liquid crystal layer; wherein, the base layer is a transparent glass or flexible polymer substrate; the electrode layer is made of indium tin oxide and photolithographically formed into a matrix of independent electrode units corresponding one-to-one with the pixels of the front-end sensor; the liquid crystal layer is filled with nematic liquid crystal, which can generate different phase velocities for two mutually perpendicular light vibration components, thereby introducing a relative phase difference, and serves as a dynamically adjustable phase delay layer under voltage control.

[0034] When there is no electric field, the liquid crystal molecules naturally align to form a half-wave plate. After the incident light passes through the liquid crystal layer, the polarization direction is rotated by a fixed angle. In this state, the modulation unit is transparent. When an electric field is applied, the electric field forces the liquid crystal molecules to rearrange, and the polarized light component in the incident light is filtered out. In this state, the modulation unit is modulated.

[0035] The technical solutions provided in the embodiments of the present invention have the following beneficial effects:

[0036] Construct a polarization fingerprint library of typical glare sources (such as vehicle lights, sunlight, and reflections) to achieve intelligent recognition of glare types, distinguish different types of glare (such as vehicle lights and road reflections), drive different partitions of the spatial light modulator, apply different and most effective modulation strategies for glare in different areas, achieve precise suppression of glare in one area and avoid one-size-fits-all shading.

[0037] By using polarization fingerprint analysis and spatial polarization correlation mapping, the characteristics of the light source and its specific location in the field of view are accurately identified. The small area where the identified glare source with specific polarization characteristics is located is suppressed, while the rest of the field of view remains highly transparent, thereby eliminating glare while maximizing the visibility of the surrounding environment.

[0038] Employing liquid crystal modulation technology, the response time is at the millisecond level, enabling closed-loop control of real-time monitoring, real-time processing, and real-time suppression. Oncoming headlights may appear in an instant, and the system can react instantly only to the local area of ​​the headlight image, and restore the light transmittance of that area immediately after the headlights move away, ensuring visual continuity.

[0039] By using a high spatial resolution sensor array and a spatial-polarization correlation mapping algorithm, the location of glare sources in the driver's field of vision can be accurately determined (e.g., horizontal direction at 10 o'clock, pitch angle -5°). This allows the actuator (spatial light modulator) to dynamically block only the pixels or areas where glare occurs, just like a digital sunshade, thus achieving precise prevention and control.

[0040] Based on dynamic modulation, light with harmful polarization characteristics is selectively suppressed while retaining polarized light in other directions. Therefore, useful polarization information (such as road conditions) and important LCD screen information are preserved, ensuring complete acquisition of driving information.

[0041] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram illustrating the principle of glare recognition and suppression as described in an embodiment of the present invention;

[0044] Figure 2 This is a flowchart of the glare recognition and suppression method described in the embodiments of the present invention;

[0045] Figure 3 This is a schematic diagram illustrating the suppression principle of the liquid crystal modulation unit in an embodiment of the present invention;

[0046] Figure 4 This is a timing diagram of the glare suppression system described in an embodiment of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0048] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0049] To address the problem of glare prevention, this invention provides a glare identification and suppression method and system. In glare identification, it abandons the traditional approach of relying solely on light intensity for glare discrimination, innovatively introducing polarization state (including polarization angle and degree of polarization) as a core discrimination feature, forming a "intensity + polarization" dual-modal sensing. Specifically, it simultaneously acquires the light intensity and polarization state information of the incident light, and uses the combination of these information to identify the glare source and its type. The discrimination process employs a polarization fingerprint feature database and a real-time matching algorithm to establish a unique polarization fingerprint feature database for different types of glare sources (such as vehicle headlights, sunlight, and reflections). The algorithm then rapidly matches and identifies real-time sensing data to determine the specific type of glare source, and compares the identified glare polarization features with... The pixel coordinates of the image sensor, i.e., the precise spatial location (XY coordinates) of the glare source in the field of view, are bound to generate a two-dimensional glare distribution matrix that characterizes the glare distribution state at different locations in the field of view. This spatializes the polarization information, enabling a leap from "perceiving the presence of glare" to "perceiving where the glare is." In terms of glare suppression, based on the recognition of glare, an independently addressable liquid crystal cell array is used as the actuator, rather than the traditional global polarizer filter. This selectively and dynamically changes the polarization direction of light in a specific spatial area, rather than simply changing its intensity or color. This forms a millisecond-level high-speed closed-loop execution chain from signal acquisition and intelligent recognition to precise execution, which can continuously sense environmental changes and dynamically adjust the execution strategy.

[0050] like Figure 1 and Figure 2 As shown, the glare recognition and suppression method includes the following steps:

[0051] Step S1: Construct a polarization feature database based on different light sources.

[0052] In this step, the polarization feature database stores the polarization fingerprints of typical glare sources in tabular form. The polarization fingerprint is an inherent and stable polarization characteristic of a preset glare source (such as vehicle headlights or water reflections). During fingerprint analysis, the preset glare source (such as vehicle headlights or water reflections) is associated and matched with its inherent and stable polarization characteristics. Like fingerprints, different types of glare have unique polarization patterns, which can be used to accurately identify glare types.

[0053] Most natural light or incoherent light sources (glare sources), after being reflected from a surface, typically form partially polarized light. This polarization state can be decomposed into a superposition of fully polarized and unpolarized light. The polarized component can be linearly polarized, elliptically polarized, or circularly polarized, depending on the specific polarization.

[0054] Angle of incidence: Near Brewster's angle, reflected light from non-metallic surfaces tends to be purely linearly polarized (the p-component is extremely small). For metals, reflected light is typically elliptically polarized.

[0055] Material properties: The refractive index of dielectric materials (such as glass and water) and metallic materials (such as aluminum and steel) is complex. Its complex characteristics cause different phase changes in the s-wave and p-wave in the reflected light, thus producing elliptically polarized reflected light from linearly polarized incident light.

[0056] Surface roughness: It can depolarize and increase the non-polarized component.

[0057] For linearly polarized light, the polarization state is completely determined by one parameter—the vibration direction angle. This angle (usually denoted as θ) p The polarization angle, relative to a reference plane (such as the incident plane), is the most intuitively understood polarization angle, for example, parallel to the incident plane (p-polarization) or perpendicular to it (s-polarization). For elliptically / circularly polarized light, the polarization state requires two parameters to describe it: the major axis orientation angle and the ellipticity angle. The major axis orientation angle is the angle between the principal axis of the ellipse and the reference plane. This angle has a similar physical meaning to the vibration direction angle of linear polarization and can be considered as the main direction of polarization. The ellipticity angle is defined as χ = arctan(minor axis / major axis), and its value is between -45° and +45°, with the positive or negative sign representing the direction of rotation (right-handed or left-handed). Circular polarization is a special case where the ellipticity angle is ±45°.

[0058] For example, taking elliptically polarized light as an example, when elliptically polarized light passes through a rotating linear polarizer, the transmitted light intensity varies with the polarizer angle θ as follows:

[0059] Mathematical expression

[0060] Let the major axis direction angle of elliptically polarized light be Ψ (relative to the reference axis), the major axis amplitude be a, and the minor axis amplitude be b, where a ≥ b ≥ 0. The relationship between the transmitted light intensity I(θ) / θ and the transmission axis angle θ of the polarizer is:

[0061]

[0062] Alternatively, it can be expressed using Stokes parameters. The Stokes parameters for elliptically polarized light are:

[0063]

[0064] Where δ is the phase difference between the two orthogonal components (δ = ±π / 2 is a positive ellipse). The transmitted light intensity is:

[0065]

[0066] Where χ is the ellipticity angle, satisfying tanχ=±b / a(−45) ∘ ≤χ≤45 ∘ -45 ∘ ≤χ≤45 ∘ ), and cos2χ=(a 2 -b 2 ) / (a 2 +b 2 ).

[0067] The flatter the ellipse (b≪a, approaching linear polarization), the more I... min ≈0, the light intensity varies greatly.

[0068] The more circular the ellipse (b≈a, close to circular polarization), the better I min ≈I max The light intensity changes little.

[0069] When the polarization is circular (a=b), the light intensity does not change with the angle and remains constant at a. 2 (or S0 / 2).

[0070] Typical glare sources include oncoming vehicle headlights, low-angle sunlight, and reflections from road surface water. The polarization characteristics are characterized using polarization fingerprints. These polarization fingerprints associate and match specific glare sources (such as vehicle headlights and water reflections) with their inherent, stable polarization characteristics. Like fingerprints, different types of glare have unique polarization patterns, used to accurately identify glare types. For example, the polarization fingerprint characteristics of oncoming vehicle headlights are: light intensity > 15000 Lux and polarization angle ∈ [0°, 15°] or [165°, 180°]; the polarization fingerprint characteristics of low-angle sunlight are: light intensity > 10000 Lux and polarization angle ≈ solar azimuth ± 90°; the polarization fingerprint characteristics of road surface water reflections are: light intensity > 12000 Lux and polarization angle ≈ Brewster angle (corresponding direction), etc.

[0071] Step S2: Acquire the field-of-view image, as well as the light intensity and polarization state of the ambient light within the field of view.

[0072] In this step, the light intensity refers to the quantified ambient light intensity, measured in Lux, which can be acquired using a light intensity sensor. The polarization state includes the angle of polarization (AoP) and the degree of polarization (DoP). The polarization angle is the angle of polarization direction, and the degree of polarization is the ratio of the intensity of the polarized portion of the light beam to the total intensity, ranging from 0 (natural light) to 1 (completely polarized). When acquiring polarization state information, a polarization direction sensor can be used to collect the corresponding data. This sensor captures the polarization angle (AoP) and degree of polarization (DoP) of the incident light in real time, outputting raw Jones vector or Stokes parameter data. The raw data contains the polarization angle and degree of polarization information. The polarization direction sensor can perform field-of-view simulation through calculation. During the acquisition of light intensity and polarization state data, the optical field of view angles are physically coincident to ensure data spatial consistency.

[0073] Step S3: Set a light intensity threshold and judge the light intensity of the current ambient light collected. If the light intensity is greater than the light intensity threshold, proceed to step S4; if the light intensity is less than or equal to the light intensity threshold, return to step S2.

[0074] In this step, glare is first preliminarily identified by light intensity. Only light with an intensity reaching a threshold is likely to cause glare. The preliminarily identified glare is then further judged and suppressed by polarization state to prevent the system from idling in low-light environments where it is not needed, thus saving power. Preferably, the light intensity threshold is 8000~10000 Lux.

[0075] Step S4: Preprocess the light intensity and polarization state data.

[0076] In this step, the preprocessing includes noise, error, and interference removal; polarization angle filtering (such as Kalman filtering) to eliminate random noise and random, weak stray polarized light interference from the environment; and retaining effective polarization signals with significant intensity and concentrated polarization direction that may originate from glare sources. Intensity correction (such as gamma correction) is also performed to compensate for the sensor's nonlinear response. Through a lookup table or mathematical function, the sensor's original output value is converted into an accurate value linearly related to the true light intensity, improving signal quality. Preferably, during noise removal, a Kalman filtering algorithm is used to weightedly fuse the polarization angle measurement value of each pixel in the current frame with the predicted value from the previous frame, effectively suppressing instantaneous, random polarization noise caused by dust, water droplets, etc., to obtain a smooth and reliable polarization angle data stream. During intensity correction, gamma correction is used, the sensor's response curve is obtained in advance, and a lookup table (LUT) is established. During gamma correction, the true light intensity value after linearization correction is quickly obtained by querying the LUT.

[0077] Step S5: Based on the preprocessed polarization state data, perform glare feature recognition on ambient light using a polarization feature database; perform spatial-polarization correlation mapping based on the field of view image to generate a binary glare distribution matrix.

[0078] In this step, the spatial-polarization correlation mapping is presented as a correspondence database or matrix, associating each specific location (X,Y coordinates) in the field of view with the polarization angle (θ) of the main polarized light detected at that location. This mapping is the basis for subsequent partitioning and directional modulation. For example, if the current ambient light is matched with the polarization feature data and the result is "vehicle headlights: high intensity + near-horizontal polarization", then a binary spatial polarization modulation matrix is ​​generated based on the current result. The polarization state data collected by the polarization direction sensor includes the corresponding spatial coordinate data. Therefore, when associating it with the coordinates in the field of view image, accurate mapping can be performed based on the coordinates. The size of the formed glare distribution matrix has the same pixel value as the polarization direction sensor and the field of view image, for example, a 1080x1920 matrix. At the same time, the matrix uses 0 and 1 as elements, where a value of "1" represents a glare source that needs to be suppressed at that spatial location, and a value of "0" represents the normal field of view.

[0079] Step S6: Analyze the binarized glare distribution matrix and generate modulation instructions based on the pixels in the matrix that require glare suppression.

[0080] In this step, based on the glare distribution matrix, which identifies which pixel locations in the field of view have glare that needs to be suppressed, instructions are generated to modulate the pixel locations that need to be modulated.

[0081] Step S7: Convert the glare distribution matrix into the corresponding analog voltage matrix; convert the modulation command into the corresponding driving voltage; apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix to achieve selective polarization state modulation of the glare pixels in the incident light; selectively filter the elliptically polarized and linearly polarized light components in the glare; and output the glare-suppressed outgoing light.

[0082] In this step, the conversion from binarized data to analog voltage can be implemented using a dynamic modulation execution layer, which converts each value (0 or 1) in the binarization matrix into the corresponding analog voltage. For example, for a value of "1" (which needs to be suppressed), a specific driving voltage V_on (e.g., 5V) is output; for a value of "0", V_off (0V) is output. The modulation process based on the driving voltage can be implemented using a spatial light modulator (SLM). The spatial light modulator is fabricated using a liquid crystal polarization rotator array.

[0083] The process of glare suppression based on an analog voltage matrix involves optical modulation control, during which the corresponding current exhibits four different waveforms in timing; including:

[0084] Sensor sampling clock: a periodic square wave with a frequency of 200Hz, indicating that the system samples and processes data in 5ms cycles;

[0085] Data processing latency: After each rising edge of the sampling clock, there is a brief, sustained high level, which represents the time required from sampling to calculating the glare distribution matrix (e.g., <1ms);

[0086] Drive voltage signal (glare area): After the data processing delay ends, it quickly jumps from 0V to 5V and remains there until the data processing of the next cycle is completed, at which point it will be changed based on the new results.

[0087] Drive voltage signal (normal zone): always maintained at 0V. Based on the same idea, this invention also provides a glare recognition and suppression system, which includes: a polarization feature database, a light intensity sensor, a polarization direction sensor, a light intensity activation module, a preprocessing module, a polarization recognition engine, a spatial polarization mapping module, and a spatial light modulator; wherein,

[0088] The polarization feature database is used to store polarization fingerprints of typical glare light sources;

[0089] The light intensity sensor is used to measure the light intensity of ambient light within the field of view;

[0090] The polarization direction sensor is used to acquire the field of view image and the polarization state of ambient light within the field of view;

[0091] The light intensity activation module is used to set the light intensity threshold and judge the light intensity of the current ambient light collected. When the light intensity is greater than the light intensity threshold, polarization suppression is triggered and the preprocessing module is activated.

[0092] The preprocessing module is used to preprocess the light intensity and polarization state data;

[0093] The polarization recognition engine is used to identify glare features of ambient light based on the preprocessed polarization state data and a polarization feature database.

[0094] The spatial polarization mapping module is used to perform spatial-polarization correlation mapping based on the field of view image to generate a binary glare distribution matrix.

[0095] The spatial light modulator is used to analyze the binarized glare distribution matrix, generate modulation instructions based on the pixels in the matrix that need glare suppression, convert the glare distribution matrix into a corresponding analog voltage matrix, convert the modulation instructions into a corresponding driving voltage, apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix, achieve selective polarization state modulation of the glare pixels in the incident light, selectively filter the elliptically polarized and linearly polarized light components in the glare, and output the glare-suppressed outgoing light.

[0096] The polarization feature database contains pre-stored standard polarization features of various glare sources; real-time acquired light intensity and polarization state data are matched with the features in the database to identify the specific type of glare source.

[0097] The light intensity sensor employs a high dynamic range (HDR) ambient light sensor (ALS), such as the ams TSL2591. This sensor can accurately quantify light intensity (in lux) and its range needs to cover more than 0 to 100,000 lux to accurately capture the full range of light from starlight to midday sunlight.

[0098] The polarization direction sensor employs a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor based on metal nanowire gratings, such as the Sony IMX250MYR. This sensor chip integrates nanowire grating polarization filters in four directions: 0°, 45°, 90°, and 135°. Each pixel consists of four sub-pixels sensing different polarization directions. With a single exposure, the Stokes parameters of each pixel across the entire field of view can be calculated in real time, thereby deriving the degree of polarization and polarization angle of the light, i.e., the direction of the Jones vector.

[0099] The polarization direction sensor can also employ a two-dimensional variable-angle heterojunction photodetector, such as a two-dimensional Te / ReSe2 variable-angle van der Waals photodetector. This device uses Si / SiO2 as a substrate and constructs a heterojunction structure with Te and ReSe2 layers at different angles through chemical vapor deposition (CVD), photolithography gold plating, and transfer processes. Due to the anisotropic lattice structure of ReSe2, this device exhibits differentiated photoelectric responses to incident light with different polarization directions, possessing rich polarization-sensitive characteristics. By designing heterojunctions with different angles, synchronous and highly sensitive detection of the polarization direction and intensity of incident light can be achieved. This detector provides the system with unprecedented polarization information sensing capabilities, a prerequisite for subsequent accurate polarization identification and dynamic suppression, and can be applied to polarization imaging, optical encryption and decryption, and other fields.

[0100] The spatial light modulator described is an electrically switchable liquid crystal variable polarizer with coplanar electrodes and no static polarization film, comprising coplanar electrodes and an electroactive layer. In the coplanar electrodes, first and second transparent electrodes are coplanarly fabricated on the same substrate in the form of alternating conductive strips. The required transverse electric field is generated by applying an alternating electric field (E2) between adjacent strips. The electroactive layer is composed of a material containing nematic liquid crystal and dichroic dyes. In the off state (without electric field), the liquid crystal can exhibit a twisted nematic alignment. The variable polarizer dynamically changes its polarization characteristics by controlling the orientation of the liquid crystal and dichroic dye molecules through an electric field. In the off state, it can output light with a specific polarization component to unpolarized incident light, with a polarization ratio as high as 70% or even over 90%. In the on state, its polarization state changes significantly. This design without a static polarization film allows its polarization axis to be continuously rotated electrically, achieving dynamic and rapid switching from a "transparent" to a "polarized" state.

[0101] Specifically, the spatial light modulator is fabricated based on a liquid crystal polarization rotator. The liquid crystal polarization rotator array consists of an array containing several independently controllable liquid crystal modulation units. Each unit can change the polarization direction of light passing through it according to the applied voltage; by controlling the entire array, different polarization modulation regions can be formed in space. Each liquid crystal modulation unit consists of a transparent electrode, an alignment layer, a liquid crystal layer, etc., and the polarization state of light is changed by altering the arrangement of liquid crystal molecules through voltage.

[0102] The structure of the liquid crystal modulation unit includes a base layer, an electrode layer, and a liquid crystal layer; optionally, it may also include an alignment layer. The base layer is a transparent glass or flexible polymer substrate; the electrode layer is made of indium tin oxide and photolithographically formed into matrix-style independent electrode units corresponding one-to-one with the pixels of the front-end sensor; the liquid crystal layer is filled with nematic liquid crystal, and its thickness is precisely designed. This liquid crystal layer can generate different phase velocities for two mutually perpendicular light vibration components, thereby introducing a relative phase difference, and acts as a dynamically adjustable phase delay layer under voltage control; the alignment layer aligns the liquid crystal molecules in a specific direction when there is no electric field. The alignment layer acts as a polarizer. In the absence of an electric field (V_off), the liquid crystal molecules naturally align to form a half-wave plate. After the incident linearly polarized light passes through the liquid crystal layer, its polarization direction is rotated by a fixed angle (e.g., 90°). In this state, the modulation unit is transparent. When an electric field is applied (V_on), the electric field forces the liquid crystal molecules to rearrange, and the polarized light component in the incident light is filtered out. In this state, the modulation unit is modulated.

[0103] Specifically, such as Figure 3 As shown, in one executable embodiment, the structure of the liquid crystal modulation unit includes: an upper glass substrate, an upper ITO electrode, liquid crystal molecules (marked with the initial orientation direction), a lower ITO electrode, and a lower glass substrate. The upper and lower electrodes are connected to an external driving circuit via wires. Based on the array of the liquid crystal modulation units, when suppressing glare, the left column "V_off state" shows that vertically polarized light is incident, and after passing through the liquid crystal layer, the polarization direction becomes horizontal, indicating that the liquid crystal molecules have a rotational effect; the right column "V_on state" shows that vertically polarized light is incident, and after passing through the liquid crystal layer, the polarization direction remains unchanged, indicating that the liquid crystal molecules lose their optical rotation ability under the action of an electric field.

[0104] In one feasible embodiment, the system may further include a polarizer and an analyzer. The polarizer and analyzer can filter 100% of the light (pure black), and the removal of this step can be adjusted between 25% and 85%.

[0105] When using the glare recognition and suppression system described in this embodiment of the invention, before recognizing and suppressing glare, the corresponding glare fingerprint features are first stored in the polarization feature database; taking a vertical polarizer as an example, the recognition and suppression process is as follows:

[0106] When a glare source (such as horizontally polarized car headlights) enters the system, its horizontally polarized light component is largely blocked by the polarizer, resulting in a sharp decrease in intensity. However, ambient useful light (such as natural light and road signs) is unpolarized light, containing polarization components in various directions, and some vertical components will always pass through the polarizer. The light intensity sensor and polarization direction sensor collect the light intensity and polarization state data of the glare source. When the light intensity reaches the threshold, the light intensity activation module triggers the glare suppression process. The preprocessing module preprocesses the glare and inputs it into the polarization recognition engine. The polarization recognition engine identifies the glare characteristics of the ambient light based on the preprocessed polarization state data and the polarization feature database. The base spatial polarization mapping module performs spatial-polarization correlation mapping on the field of view image to generate a binary glare distribution matrix. For the region marked as glare (matrix value 1), the spatial light modulator applies a V_on voltage to the corresponding pixel, and the liquid crystal layer does not work. The remaining intense light from the glare source (already vertically polarized) remains unchanged and continues to propagate backward. In the normal region (matrix value 0), the corresponding pixel has no voltage (V_off), and the liquid crystal layer operates, rotating the vertically polarized light from the ambient light by 90 degrees to horizontal polarization. The vertically polarized light from the glare region is completely blocked by the analyzer, achieving glare suppression. The ambient light from the normal region, now horizontally polarized, passes smoothly through the analyzer, which is orthogonal to the polarization direction of the polarizer, and is seen by the human eye, ensuring a normal field of vision.

[0107] like Figure 4 As shown, when the glare recognition and suppression system performs optical modulation control in a time sequence, there are four waveforms in sequence, including:

[0108] Sensor sampling clock: a periodic square wave with a frequency of 200Hz, indicating that the system samples and processes data in 5ms cycles;

[0109] Data processing latency: After each rising edge of the sampling clock, there is a brief, sustained high level, which represents the time required from sampling to calculating the glare distribution matrix (e.g., <1ms);

[0110] Drive voltage signal (glare area): After the data processing delay ends, it quickly jumps from 0V to 5V and remains there until the data processing of the next cycle is completed, at which point it will be changed based on the new results.

[0111] Drive voltage signal (normal zone): always remains at 0V.

[0112] It should be noted that when there is no need to polarize or analyze the light, the light intensity and polarization characteristics are directly collected at the input, and no polarization analysis is required at the output. The rest of the process is the same as described above.

[0113] In this embodiment, each module is implemented using a processor, with additional memory added as needed for storage. The processor can be, but is not limited to, a microprocessor (MPU), a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), other programmable logic devices, discrete gates, transistor logic devices, discrete hardware components, etc. The memory can include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory can also be at least one storage device located remotely from the aforementioned processor.

[0114] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0115] Therefore, the glare recognition and suppression method and system provided in this invention identifies harmful glare sources by real-time detection of the polarization state (direction and intensity) of incident light, and drives a spatial light modulator to selectively attenuate light in a specific area and with a specific polarization direction. During suppression, an independently addressable liquid crystal cell array is used as the actuator, rather than a traditional global color-changing element (such as an electrochromic layer). By applying voltage to specific pixel units, the polarization direction of light in a specific spatial area is selectively and dynamically changed, rather than its intensity or color. Based on this, the modulator responds to the control signal and selectively modulates only the polarization state of light at a specific location in the field of view, thereby constructing a millisecond-level high-speed closed-loop system from signal acquisition and intelligent recognition to precise execution. This system can continuously sense environmental changes and dynamically adjust the execution strategy.

[0116] The present invention has at least the following beneficial effects:

[0117] Multi-dimensional perception: Introducing polarization state (polarization angle, degree of polarization) as a discrimination feature, forming a "intensity + polarization" dual-mode perception with light intensity, breaking through the limitations of traditional judgment based solely on light intensity;

[0118] Polarization Feature Database: Construct a polarization fingerprint database of typical glare sources (such as car lights, sunlight, and reflections) to achieve precise suppression with a "one-size-fits-all" approach, avoiding "one-size-fits-all" shading; suppress only the location of glare sources with harmful polarization characteristics, preserving the details of the surrounding environment to the maximum extent.

[0119] High-speed response and low power consumption: Fully electronic operation, eliminating the coloring / fading chemical reaction process of electrochromic materials, improving response speed from seconds to milliseconds, far exceeding traditional technologies such as electrochromic technology, meeting the suppression requirements of high-speed moving glare light sources such as vehicle lights; modulation is applied only to the target pixel, resulting in extremely low power consumption;

[0120] Compatibility and scalability: It can provide a data foundation for systems such as ADAS and smart glasses, and support adaptation to complex scenarios.

[0121] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the 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 inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for glare recognition and suppression, characterized in that, The method includes the following steps: Step S1: Construct a polarization feature database based on different light sources; Step S2: Acquire the field-of-view image, as well as the light intensity and polarization state of the ambient light within the field of view; Step S3: Set a light intensity threshold and judge the light intensity of the current ambient light collected. If the light intensity is greater than the light intensity threshold, proceed to step S4; if the light intensity is less than or equal to the light intensity threshold, return to step S2. Step S4: Preprocess the light intensity and polarization state data; Step S5: Based on the preprocessed polarization state data, perform glare feature identification on ambient light using a polarization feature database. A binary glare distribution matrix is ​​generated by performing spatial-polarization correlation mapping based on the field of view image; Step S6: Analyze the binarized glare distribution matrix and generate modulation instructions based on the pixels in the matrix that require glare suppression. Step S7: Convert the glare distribution matrix into the corresponding analog voltage matrix; convert the modulation command into the corresponding driving voltage; apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix to achieve selective polarization state modulation of the glare pixels in the incident light; selectively filter the elliptically polarized and linearly polarized light components in the glare; and output the glare-suppressed outgoing light.

2. The method according to claim 1, characterized in that, The polarization feature database stores polarization fingerprints of typical glare sources, and the polarization fingerprints are inherent and stable polarization features of the preset glare sources, which can be used to accurately identify the type of glare.

3. The method according to claim 1, characterized in that, The polarization state includes the polarization angle and the degree of polarization of light. The polarization angle is the angle of polarization direction, and the degree of polarization is the ratio of the intensity of the polarized part of the light beam to the total intensity, with a value ranging from 0 to 1. Here, 0 represents natural light and 1 represents fully polarized light.

4. The method according to claim 1, characterized in that, The light intensity threshold is 10,000 Lux.

5. The method according to claim 1, characterized in that, The preprocessing in step S4 includes eliminating noise, errors, and interference; wherein, When eliminating noise, the Kalman filter algorithm is used to weight and fuse the polarization angle measurement value of each pixel in the current frame with the predicted value of the previous frame, which effectively suppresses instantaneous and random polarization noise and obtains a smooth and reliable polarization angle data stream. To eliminate interference, perform strong light correction. Use gamma correction to obtain the sensor's response curve in advance and build a lookup table (LUT). Then, by querying the LUT, quickly obtain the true light intensity value after linearization correction.

6. The method according to claim 1, characterized in that, In step S5, the spatial-polarization correlation mapping is presented as a correspondence database or matrix, which associates the X and Y coordinates of each specific location in the field of view with the polarization angle θ of the main polarized light detected at that location.

7. The method according to claim 1, characterized in that, In step S7, when converting the glare distribution matrix into the corresponding analog voltage matrix, each 0 or 1 in the binarized matrix is ​​converted into the corresponding analog voltage; for the point where "1" value needs to be suppressed, a specific driving voltage V_on is output; for the point where "0" value is normal, V_off is output.

8. A glare recognition and suppression system, characterized in that, The system includes: a polarization feature database, a light intensity sensor, a polarization direction sensor, a light intensity activation module, a preprocessing module, a polarization recognition engine, a spatial polarization mapping module, and a spatial light modulator; wherein... The polarization feature database is used to store polarization fingerprints of typical glare light sources; The light intensity sensor is used to measure the light intensity of ambient light within the field of view; The polarization direction sensor is used to acquire the field of view image and the polarization state of ambient light within the field of view; The light intensity activation module is used to set the light intensity threshold and judge the light intensity of the current ambient light collected. When the light intensity is greater than the light intensity threshold, polarization suppression is triggered and the preprocessing module is activated. The preprocessing module is used to preprocess the light intensity and polarization state data; The polarization recognition engine is used to identify glare features of ambient light based on the preprocessed polarization state data and a polarization feature database. The spatial polarization mapping module is used to perform spatial-polarization correlation mapping based on the field of view image to generate a binary glare distribution matrix. The spatial light modulator is used to analyze the binarized glare distribution matrix, generate modulation instructions based on the pixels in the matrix that need glare suppression, convert the glare distribution matrix into a corresponding analog voltage matrix, convert the modulation instructions into a corresponding driving voltage, apply the corresponding driving voltage to the corresponding pixel unit in the analog voltage matrix, achieve selective polarization state modulation of the glare pixels in the incident light, selectively filter the elliptically polarized and linearly polarized light components in the glare, and output the glare-suppressed outgoing light.

9. The system according to claim 8, characterized in that, The spatial light modulator includes coplanar electrodes and an electroactive layer. In the coplanar electrodes, first and second transparent electrodes are coplanarly fabricated on the same substrate in the form of alternating conductive strips. An alternating electric field is applied between adjacent strips to generate the desired transverse electric field. The electroactive layer is composed of a material containing nematic liquid crystal and dichroic dyes. In the off state (without electric field), the liquid crystal can exhibit a twisted nematic arrangement. The orientation of the liquid crystal and dichroic dye molecules is controlled by the electric field, thereby dynamically changing their polarization characteristics. In the off state, it can output light with a specific polarization component from unpolarized incident light, with a polarization ratio exceeding 70%. In the on state, the polarization state changes significantly.

10. The system according to claim 8, characterized in that, The spatial light modulator consists of an array containing several independently controllable liquid crystal modulation units; The structure of the liquid crystal modulation unit includes: a base layer, an electrode layer, and a liquid crystal layer; wherein, the base layer is a transparent glass or flexible polymer substrate; the electrode layer is made of indium tin oxide and photolithographically formed into a matrix of independent electrode units corresponding one-to-one with the pixels of the front-end sensor; the liquid crystal layer is filled with nematic liquid crystal, which can generate different phase velocities for two mutually perpendicular light vibration components, thereby introducing a relative phase difference, and serves as a dynamically adjustable phase delay layer under voltage control. When there is no electric field, the liquid crystal molecules naturally align to form a half-wave plate. After the incident light passes through the liquid crystal layer, the polarization direction is rotated by a fixed angle. In this state, the modulation unit is transparent. When an electric field is applied, the electric field forces the liquid crystal molecules to rearrange, and the polarized light component in the incident light is filtered out. In this state, the modulation unit is modulated.

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