Tilt Shift lens-based transparent polarization material visual detection method and system

Abstract

The invention discloses a Tilt Shift lens-based transparent polarization material visual detection method and system. The method comprises the following steps of S1, installing a camera and determining the position posture of the camera through a software display window of the camera; s2, adjusting the flatness of the Tilt Shift lens by using a gradienter; the Tilt axis and the Shift axis of the Tilt Shift lens are adjusted; s3, continuing to adjust the Tilt axis and the Shift axis of the Tilt Shift lens according to the display image; the definition and the illuminance of the display image of the polarization material reach the standard value range; s4, acquiring an image of the polarization material by using a camera; and S5, performing flaw detection on the image of the polarization material by using multiple algorithms. By adjusting the Tilt axis and the Shift axis of the Tilt Shift lens, the problem of imaging overexposure caused by the fact that a light source enters a visual field is solved, and focal ring adjustment is synchronously matched, so that the definition consistency before and after a large scene interval during oblique shooting can be realized, and the crack detection of the large-size transparent polaroid is realized.

Description

Technical Field

[0001] This invention relates to the field of defect detection, and more specifically to a visual inspection method and system for transparent polarized materials based on a Tilt Shift lens. Background Technology

[0002] Currently, the detection of defects such as cracks in transparent polarizer materials is limited by the material's optical properties. A complete and accurate image cannot be directly captured by a camera during testing; therefore, manual visual inspection under a light source is still required. This significantly restricts production efficiency and yield for large-scale consumer electronics applications.

[0003] In existing technologies, cracks in polarizers can only be accurately identified and observed by applying external light source illumination within a specific tilt angle range. Because polarizers are relatively large, their length typically ranges from 100mm to 400mm depending on the application. Therefore, conventional lenses generally cannot meet the needs of shooting such large depths of field.

[0004] In summary, there is a need to design a visual inspection method and system for transparent polarized materials based on a Tilt Shift lens to solve the problems in the existing technology. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a visual inspection method and system for transparent polarizing materials based on a Tilt Shift lens, which solves the problem that polarizing film cracks and defects can only be detected manually.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A visual inspection method for transparent polarized materials based on a Tilt Shift lens includes the following steps: Step S1: Install the camera and determine its position and orientation through the camera's software display window; Step S2: Use a level to adjust the flatness of the Tilt Shift lens; adjust the Tilt axis and Shift axis of the Tilt Shift lens; Step S3: Continue to adjust the Tilt and Shift axes of the Tilt and Shift lenses according to the displayed image of the polarizing material in the software display window until the sharpness and illumination of the displayed image of the polarizing material reach the standard value range. Step S4: Use a camera to acquire images of the polarizing material; Step S5: Use multiple algorithms to detect defects in the image of polarized material.

[0007] In some embodiments of the present invention, in step S1, there are two cameras, each fixed to a position adjustment platform by a pose adjustment system; the position adjustment platform is arranged parallel to the worktable; the pose adjustment system is slidably connected to the position adjustment platform; the pose adjustment system is used to adjust the field of view of the camera.

[0008] In some embodiments of the present invention, after the position and orientation adjustment in step S1, the edge of the polarizing material is parallel to the edge of the display window, and the light source does not directly enter the display window.

[0009] In some embodiments of the present invention, in step S2, the Tilt Shift lens is determined to be parallel to the camera based on the flatness.

[0010] In some embodiments of the present invention, in step S3, the sharpness and illumination of the central region of the polarizing material are first determined by magnifying the displayed image; then, the displayed image is moved to the edge position of the polarizing material at the same magnification to determine the sharpness and illumination of the edge position of the polarizing material.

[0011] In some embodiments of the present invention, the specific steps of defect detection in step S5 include: The image acquired in step S4 is preprocessed to obtain a filtered image; Then, each column of the filtered image is processed in a loop to obtain the sub-pixel center coordinates of the current column; After the loop ends, the image is processed again to output a high-precision sub-pixel center point sequence.

[0012] In some embodiments of the present invention, the loop process includes: A rough center point is obtained by coarsely extracting the pixel-level center using the gray-scale centroid method; Select the extraction window based on the approximate center point; The subpixel extraction algorithm is selected to calculate the subpixel center coordinates of the filtered image; the subpixel extraction algorithm includes at least the gray-level centroid method, Gaussian fitting method and Steger algorithm.

[0013] In some embodiments of the present invention, a visual inspection system for transparent polarized materials based on a Tilt Shift lens is provided to implement the above-described visual inspection method for transparent polarized materials, comprising: The camera pose adjustment module includes a position adjustment platform and an attitude adjustment system; The display window adjustment module is used to adjust the Tilt axis and Shift axis of the Tilt Shift lens to achieve the standard value range for the sharpness and illumination of the displayed image of the polarizing material; The image acquisition and processing module is used to acquire images of polarized materials and perform defect detection on the acquired images; The communication module is used to communicate with external devices.

[0014] In some embodiments of the present invention, an electronic device is provided, comprising: A processor, and a memory and a transceiver communicatively connected to the processor; The memory stores computer-executed instructions; the transceiver is used for sending and receiving data. The processor executes computer execution instructions stored in the memory to implement the above-described visual inspection method for transparent polarized materials.

[0015] In some embodiments of the present invention, a computer-readable storage medium is provided, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the above-described visual inspection method for transparent polarized materials.

[0016] The technical solution of the present invention has the following technical effects compared with the prior art: This invention avoids overexposure caused by light entering the field of view by adjusting the Tilt and Shift axes of the Tilt-Shift lens, i.e., the orientation of the display window in both directions. Furthermore, by simultaneously adjusting the focal length, it ensures consistent sharpness across a large scene area when shooting at an angle. This enables the detection of cracks in large-sized transparent polarizing filters. It overcomes the limitations of current methods that rely solely on manual inspection, thus improving detection efficiency and accuracy. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the 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.

[0018] Figure 1 This is a schematic diagram of the visual inspection process for transparent polarized materials as shown in Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the visual inspection system for transparent polarized materials.

[0020] Figure 3 This is a schematic diagram of the structure of the electronic device.

[0021] Reference numerals: 100, Visual inspection system for transparent polarized materials; 110, Position adjustment platform; 120, Attitude adjustment system; 130, Display window adjustment module; 140, Camera; 200, Electronic equipment; 210, Processor; 220, Memory; 230, Transceiver. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, direct connections, or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0028] Example 1, Reference Figure 1 As shown, a visual inspection method for transparent polarized materials based on a Tilt Shift lens includes the following steps: Step S1: Install the camera and determine its position and orientation through the camera's software display window; Reference Figure 2 As shown, there are two cameras, which are fixed to the position adjustment platform by the pose adjustment system. The position adjustment platform is set parallel to the worktable. The pose adjustment system is slidably connected to the position adjustment platform. Specifically, the installation direction of the position adjustment platform is defined as the X-axis. That is, when the pose adjustment system slides along the position adjustment platform with the camera, the camera moves along the X-axis.

[0029] The pose adjustment system is used to adjust the field of view of the camera; specifically, the camera adopts a binocular orthogonal architecture. Figure 2 The workbench shown has an open detection space, in which the pose adjustment system can adjust the imaging field of view of the camera on the top surface of the detection space.

[0030] In some embodiments of the present invention, the adjustment of the camera pose is based on the camera's software display window. That is, by observing the display window, the position and orientation of the camera are initially adjusted for positioning, so that the edge of the transparent polarizing material being measured is as parallel as possible to the edge of the display window, and the light source is avoided from directly entering the camera.

[0031] Step S2: Use a level to adjust the flatness of the Tilt Shift lens; adjust the Tilt axis and Shift axis of the Tilt Shift lens; Specifically, step S21 involves using a level to adjust the flatness of the Tilt Shift lens; this ensures that the positional relationship between the Tilt Shift lens and the camera remains horizontal. Based on the level's display, if the lens is not horizontal, it is rotated to a horizontal position.

[0032] Step S2: Adjust the Tilt and Shift axes of the Tilt and Shift lenses. In this embodiment, the lens can be tilted along the optical axis by adjusting the Tilt axis, and then the lens can be translated along the direction perpendicular to the optical axis by adjusting the Shift axis.

[0033] Specifically, you can adjust Tilt to 1 to tilt the lens upwards and lock the lock knob. Adjust Shift to 0.5 and lock the lock knob.

[0034] Step S3, continue to refer to Figure 1 As shown, continue adjusting the Tilt and Shift axes of the Tilt and Shift lenses based on the displayed image of the polarizing material in the software display window until the sharpness and illuminance of the displayed image of the polarizing material reach the standard value range. Specifically, firstly, by magnifying the displayed image (in this embodiment, the magnification can be increased to 100%), the central region of the polarizing material is observed. Alternatively, the focal ring can be rotated while avoiding forcefully touching the lens to determine if the sharpness and illumination of the central region of the polarizing material meet the standard value range, i.e., the central region of the polarizing material reaches the optimal sharpness state.

[0035] Then, at the same magnification, the display image is moved to the edge of the polarizing material, that is, the edge of the polarizing material is observed to determine whether the sharpness and illuminance of the edge of the polarizing material can meet the standard value range.

[0036] In some embodiments of the present invention, if the edge of the polarizer is not clear, loosen the lock knob, readjust the Tilt, and tighten the lock knob again, and check step by step according to the above steps; if the effect is still not good, continue to adjust the Tilt scale until the best clarity effect is achieved, and then tighten the lock knob.

[0037] Step S4: Use a camera to acquire images of the polarizing material; specifically, when the polarizing material reaches the optimal state of illumination and clarity across the entire field of view, perform coded structured light scanning on the polarizer to generate a full-field image.

[0038] In some embodiments of the present invention, 24 photographs are taken for any single point of the polarizing material.

[0039] Step S5: Use multiple algorithms to detect defects in the image of polarized material.

[0040] Specifically, step S51 involves preprocessing the image acquired in step S4 to obtain a filtered image; In step S4, the original laser stripe image is obtained. In this step, filtering is performed, which can be done by Gaussian filtering or median filtering. The region of interest is selected for the filtered image.

[0041] S52. Then, each column of the filtered image is processed in a loop to obtain the sub-pixel center coordinates of the current column; S521. Use the grayscale centroid method to coarsely extract the pixel-level center to obtain a rough center point; S522. Using a rough center point as the core, select an N×N extraction window, for example: 3×3, 5×5.

[0042] S523. Select different sub-pixel extraction algorithms according to the detection requirements.

[0043] In some embodiments of the present invention, if the detection method requires speed as a priority, the gray-scale centroid method is adopted, and gray-scale weighted average calculation is performed within the extraction window, and finally the sub-pixel center coordinates of the current column are output.

[0044] In some embodiments of the present invention, if the detection method requires the highest accuracy, the Steger algorithm is used, as follows: Step 1: Calculate the Hessian matrix for each pixel; The Hessian matrix is ​​a 2×2 matrix that contains the first and second derivative information of the image at that point.

[0045] For any point A(x0, y0) on the image, the Hessian matrix can be represented as:

[0046] The Hessian matrix consists of four partial derivatives of a point in the image along different directions, which can determine the direction of the maximum absolute value of the second-order directional derivative of point A.

[0047] Step 2: Using the eigenvectors and eigenvalues ​​of the Hessian matrix, determine the normal direction (n) of the edge points. x n y ); Because the eigenvalues ​​of the Hessian matrix describe the concavity and convexity of its eigenvectors near a given point, the larger the eigenvalue, the stronger the convexity. The direction with the largest eigenvalue is the centerline direction of the edge, and its corresponding eigenvector is the normal direction. By setting a threshold, we can filter and obtain preliminary edge points.

[0048] Step 3: Calculate the sub-pixel coordinates of the center point using the Taylor expansion of the normal direction and the surface equation.

[0049] Specifically, near the edge point (pixel level) initially determined in step two, the function near that point is approximated using Taylor expansion; then, the derivative function is calculated in the normal direction and set to 0 to solve for the sub-pixel level center point.

[0050] The subpixel coordinates of the line center are: (x i y i ) = (x0 + tn x y0+tn y ); The polynomial (Taylor expansion) of the light intensity distribution along the normal direction of the current point A(x0, y0) is constructed as follows: ; Where I(x0, y0) is the pixel grayscale value of pixel A. This represents the value of the first derivative. This represents the value of the second derivative, where t is an unknown parameter.

[0051] The point where the derivative with respect to t is zero is the point where the pixel value is the largest, which is also the center of the pixel. The formula is:

[0052] The formula for calculating t is:

[0053] satisfy .

[0054] Step 4: Depending on the required precision, steps 1 to 3 can be iterated to further refine the sub-pixel center coordinates, and finally the sub-pixel center coordinates of the current column are output.

[0055] In some embodiments of the present invention, if the detection method requires a balance between accuracy and speed, a Gaussian fitting method is used to fit the gray-scale distribution of the light stripe cross section with a Gaussian function, solve for the peak point of the function, and finally output the sub-pixel center coordinates of the current column.

[0056] S524. After the loop ends, the image is processed again and a high-precision sub-pixel center point sequence of the image is output.

[0057] Specifically, the reprocessing steps include outlier removal, moving average filtering, and spline curve fitting.

[0058] The moving average filtering step involves adaptive mean filtering of the image obtained in step S523. It dynamically adjusts the filtering range based on local statistical characteristics to more effectively remove noise while preserving details in the area to be detected. The core idea of ​​this step is to use a fixed-size sliding window to traverse each pixel of the image. Based on the statistical characteristics of the pixels within the window (such as mean and variance), it determines whether the current pixel is an interference point (dust, lint, etc.) and performs smoothing filtering accordingly. The specific implementation steps are as follows: First, set the initial size of the filtering sliding window (e.g., 3x3, 5x5, etc.) and the maximum size of the filtering sliding window. Also, set the threshold for judging noise points (usually set according to the noise level of the image).

[0059] 2. Use a filtering sliding window of initial size to traverse each pixel of the original image. For each pixel, extract the pixel value within the filtering sliding window centered on it; and calculate the pixel mean and pixel variance within the filtering sliding window.

[0060] Third, first calculate the difference between the gray value of the current pixel and the average pixel value in the sliding window. Compare this difference with the threshold set in step one for judging noise points. If the difference is greater than the noise point threshold, then the current pixel is judged as a noise point. At the same time, the average pixel value in the filtering sliding window where the current pixel is located is output as the new pixel value of the current pixel.

[0061] 4. If the current pixel does not meet the noise point judgment condition under the initial filtering sliding window, increase the size of the filtering sliding window and repeat steps 2 and 3 to continue to judge whether the current pixel meets the noise point condition; until the size of the filtering sliding window is increased to the maximum size.

[0062] 5. Use a filtering sliding window to traverse other pixels, identify noise points, and output the second-filtered image.

[0063] The technical solution of the present invention has the following technical effects compared with the prior art: This invention avoids overexposure caused by light entering the field of view by adjusting the Tilt and Shift axes of the Tilt-Shift lens, i.e., the orientation of the display window in both directions. Furthermore, by simultaneously adjusting the focal length, it ensures consistent sharpness across a large scene area when shooting at an angle. This enables the detection of cracks in large-sized transparent polarizing filters. It overcomes the limitations of current methods that rely solely on manual inspection, thus improving detection efficiency and accuracy.

[0064] Example 2: This example will be based on Figure 2 and Figure 3 Describes a visual inspection system 100 for transparent polarized materials and an electronic device 200.

[0065] For the visual inspection system 100 for transparent polarizing materials, refer to... Figure 2 As shown, it includes: The camera pose adjustment module includes a position adjustment platform 110 and an attitude adjustment system 120. The position adjustment platform 110 is set on a workbench, which has three enclosures to form a detection space, and the position adjustment platform 110 is located in the detection space. The position adjustment platform 110 is specifically a parallel guide rail. The attitude adjustment system 120 can slide along the position adjustment platform 110 to adjust the distance between the camera and the object to be measured.

[0066] The attitude adjustment system 120 can achieve multi-axis rotation, thereby enabling the camera's field of view to be adjusted on the top surface of the detection space.

[0067] The display window adjustment module 130 is used to adjust the Tilt axis and Shift axis of the Tilt Shift lens to achieve the sharpness and illumination of the displayed image of the polarizing material within the standard value range; The image acquisition and processing module includes a camera 140 and its software, used to acquire images of polarized materials and perform defect detection on the acquired images; the camera 140 is fixed to the end of the attitude adjustment system 120, and the camera 140 is equipped with a TiltShift lens.

[0068] The communication module is used to communicate with external devices.

[0069] It should be understood that the image acquisition and processing module here is embodied in the form of a functional module. The term "module" here can refer to application-specific integrated circuits (ASICs), electronic circuits, processors (e.g., shared processors, proprietary processors, or group processors) and memories for executing one or more software or firmware programs, integrated logic circuits, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the image acquisition and processing module can be specifically the electronic device 200 in the above embodiments, or the functions of the electronic device 200 in the above embodiments can be integrated into the image acquisition and processing module. The image acquisition and processing module can be used to execute the various processes and / or steps corresponding to the electronic device 200 in the above method embodiments; to avoid repetition, these will not be described again here.

[0070] Reference Figure 3As shown, in this embodiment, an electronic device 200 is provided, including: Processor 210, and memory 220 and transceiver 230 communicatively connected to said processor; The memory 220 stores computer-executed instructions; the transceiver 230 is used for sending and receiving data. The processor 210 executes the computer execution instructions stored in the memory 220 to implement the visual inspection method for transparent polarized materials in Embodiment 1.

[0071] It should be understood that the electronic device 200 can be used to perform the corresponding steps and / or processes in the above method embodiments. Optionally, the memory 220 may include read-only memory and random access memory, and provide instructions and data to the processor. A portion of the memory 220 may also include non-volatile random access memory. For example, the memory 220 may also store device type information. The processor 210 can be used to execute instructions stored in the memory 220, and when the processor 210 executes the instructions, the processor 210 can perform the corresponding steps and / or processes in the above method embodiments.

[0072] It should be understood that, in the embodiments of this application, the processor 210 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0073] In implementation, each step of the above method can be completed by the integrated logic circuitry of the hardware in the processor 210 or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly embodied in the execution by the hardware processor, or by a combination of hardware and software modules in the processor 210. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0074] Example 3: In this example, a computer-readable storage medium is provided, which stores computer-executable instructions. When executed by a processor, the computer-executable instructions are used to implement the visual detection method for transparent polarized materials in Example 1.

[0075] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0076] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0078] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0079] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0080] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0081] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0082] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A visual inspection method for transparent polarized materials based on a Tilt Shift lens, characterized in that, Includes the following steps: Step S1: Install the camera and determine its position and orientation through the camera's software display window; Step S2: Use a level to adjust the flatness of the Tilt Shift lens; adjust the Tilt axis and Shift axis of the Tilt Shift lens; Step S3: Continue to adjust the Tilt and Shift axes of the Tilt and Shift lenses according to the displayed image of the polarizing material in the software display window until the sharpness and illumination of the displayed image of the polarizing material reach the standard value range. Step S4: Use a camera to acquire images of the polarizing material; Step S5: Use multiple algorithms to detect defects in the image of polarized material.

2. The visual inspection method for transparent polarized materials according to claim 1, characterized in that, In step S1, there are two cameras, which are fixed to the position adjustment platform by a pose adjustment system; the position adjustment platform is set parallel to the worktable; the pose adjustment system is slidably connected to the position adjustment platform; the pose adjustment system is used to adjust the field of view of the camera.

3. The visual inspection method for transparent polarized materials according to claim 1, characterized in that, After the position and orientation adjustment in step S1, the edge of the polarizing material is parallel to the edge of the display window, and the light source does not directly enter the display window.

4. The visual inspection method for transparent polarized materials according to claim 1, characterized in that, In step S2, the Tilt Shift lens is determined to be parallel to the camera based on the flatness.

5. The visual inspection method for transparent polarized materials according to claim 1, characterized in that, In step S3, the sharpness and illumination of the central region of the polarizing material are first determined by magnifying the displayed image; then, the displayed image is moved to the edge of the polarizing material at the same magnification to determine the sharpness and illumination of the edge of the polarizing material.

6. The visual inspection method for transparent polarized materials according to claim 1, characterized in that, The specific steps for defect detection in step S5 include: The image acquired in step S4 is preprocessed to obtain a filtered image; Then, each column of the filtered image is processed in a loop to obtain the sub-pixel center coordinates of the current column; After the loop ends, the image is processed again to output a high-precision sub-pixel center point sequence.

7. The visual inspection method for transparent polarized materials according to claim 6, characterized in that, The loop process includes: A rough center point is obtained by coarsely extracting the pixel-level center using the gray-scale centroid method; Select the extraction window based on the approximate center point; The subpixel extraction algorithm is selected to calculate the subpixel center coordinates of the filtered image; the subpixel extraction algorithm includes at least the gray-level centroid method, Gaussian fitting method and Steger algorithm.

8. A visual inspection system for transparent polarized materials based on a Tilt Shift lens, characterized in that, To implement the visual inspection method for transparent polarized materials as described in any one of claims 1-7, the method includes: The camera pose adjustment module includes a position adjustment platform and an attitude adjustment system; The display window adjustment module is used to adjust the Tilt axis and Shift axis of the Tilt Shift lens to achieve the standard value range for the sharpness and illumination of the displayed image of the polarizing material; The image acquisition and processing module is used to acquire images of polarized materials and perform defect detection on the acquired images; The communication module is used to communicate with external devices.

9. An electronic device, characterized in that, include: A processor, and a memory and a transceiver communicatively connected to the processor; The memory stores computer-executed instructions; the transceiver is used for sending and receiving data. The processor executes computer execution instructions stored in the memory to implement the visual inspection method for transparent polarized materials as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the visual inspection method for transparent polarized materials as described in any one of claims 1-7.

Images