Method, device and medium for optimizing the accuracy of photogrammetric modeling based on cross polarization

Abstract

The present application relates to a method, device and medium for optimizing the accuracy of photogrammetric modeling based on cross polarization, belonging to the field of remote sensing technology. The method includes: designing and manufacturing a light source polarization component on a photogrammetric device based on the three-dimensional model of a flash on the photogrammetric device; installing the light source polarization component on the flash and the camera lens of the photogrammetric device respectively, so as to perform photogrammetric scanning on the subject to be three-dimensionally reconstructed based on cross polarization technology to obtain a measurement image of the subject; processing the measurement image to obtain a processed image; in a photogrammetric model generation software, generating a three-dimensional model of the subject based on the processed image; optimizing the three-dimensional model of the subject to obtain a model generated by performing photogrammetry on the subject; which can improve the quality of three-dimensional reconstruction, improve the model reconstruction efficiency, generate a highly realistic model, simplify the operation process, have a wide range of application fields and low economic costs.

Description

Technical Field

[0001] The present application relates to a method, device, and medium for optimizing the accuracy of photogrammetric modeling based on cross-polarization, and belongs to the field of remote sensing technology. Background Art

[0002] Photogrammetric modeling is a technology that uses photogrammetry to perform three-dimensional digital modeling of objects or the ground by taking photos or satellite images. It is widely used in fields such as topographic mapping, urban planning, architectural design, and cultural relics protection. This technology involves multiple disciplines such as photogrammetry, digital image processing, and three-dimensional modeling, and is an important branch of remote sensing technology. Through photogrammetric modeling, information such as the three-dimensional shape, position, and size of spatial targets can be accurately obtained, providing important basic data for related applications. It provides efficient data collection and analysis means for various industries.

[0003] Traditional photogrammetry and three-dimensional reconstruction methods have some limitations and challenges. Photos scanned using ordinary photogrammetry schemes often have problems such as reflection and shadow, which affect the quality of three-dimensional reconstruction and do not have realistic Physically Based Rendering (PBR) material characteristics. In addition, since the three-dimensional reconstruction process involves a large amount of image resources and complex processing procedures, how to optimize each link to improve efficiency and quality is also an urgent problem to be solved. Therefore, how to simplify the photogrammetry process, improve the efficiency and quality of three-dimensional reconstruction, and support the generation of PBR materials while ensuring the accuracy and realism of the model is an important challenge in this field. Summary of the Invention

[0004] The present application provides a method, device, and medium for optimizing the accuracy of photogrammetric modeling based on cross-polarization, which can solve the problems of harsh environmental requirements, difficult-to-guarantee shooting accuracy, and high memory occupancy in photogrammetric modeling. The present application provides the following technical solutions:

[0005] In a first aspect, a method for optimizing the accuracy of photogrammetric modeling based on cross-polarization is provided, and the method includes:

[0006] Based on the three-dimensional model of the flash on the photogrammetry equipment, design and manufacture a light source polarization component on the photogrammetry equipment; wherein, the light source polarization component includes a light source polarization accessory and a polarizing plate;

[0007] Install the light source polarization component on the flash and the camera lens of the photogrammetry equipment respectively, so as to perform photogrammetric scanning on the subject to be three-dimensionally reconstructed based on cross-polarization technology, and obtain the measurement image of the subject;

[0008] Process the measurement image to obtain a processed image;

[0009] In the photogrammetry model generation software, a three-dimensional model of the subject is generated based on the processed image;

[0010] Optimize the three-dimensional model of the subject to obtain a model generated by photogrammetry of the subject.

[0011] Optionally, based on the three-dimensional model of the flash on the photogrammetry equipment, design and manufacture a light source polarization component on the photogrammetry equipment, including:

[0012] Perform photogrammetry on the flash to obtain a photogrammetry image of the flash;

[0013] Import the photogrammetry image of the flash into three-dimensional software for three-dimensional reconstruction, delete the generated redundant areas, export the primitive model of the flash, and obtain the three-dimensional model of the flash;

[0014] Design a three-dimensional model of the accessory of the light source polarization accessory adapted to the three-dimensional model of the flash;

[0015] Manufacture a light source polarization accessory based on the three-dimensional model of the accessory through a 3D printer;

[0016] Based on the assembly space at the first assembly position on the light source polarization accessory, cut the polarizing film to obtain a polarizing film adapted to the assembly space, and assemble the cut polarizing film to the light source polarization accessory through the first assembly position to obtain the light source polarization component.

[0017] Optionally, the design of the three-dimensional model of the accessory of the light source polarization accessory adapted to the three-dimensional model of the flash includes:

[0018] Design the three-dimensional model of the accessory using a hollowing process;

[0019] Set a plurality of holes inside the three-dimensional model of the accessory to inlay magnet blocks, and the iron blocks are used to quickly assemble the light source polarization accessory to the flash.

[0020] Optionally, the photogrammetry scanning of the subject to be three-dimensionally reconstructed based on the cross-polarization technology to obtain the measurement image of the subject includes:

[0021] Adjust the flash power to full power and set the format of the measurement image to Raw;

[0022] Perform photogrammetry scanning on the upper half and the lower half of the subject respectively based on the cross-polarization technology to obtain the measurement image of the subject;

[0023] Place the color card in the same light and shadow environment of the main body, and take a photo of the color card based on the cross-polarization technology.

[0024] Optionally, performing photogrammetric scanning on the upper half and the lower half of the main body respectively based on the cross-polarization technology to obtain the measurement image of the main body, including:

[0025] When performing photogrammetric scanning on each part respectively, keep the physical distance between the photogrammetric equipment and the main body unchanged, take photos of the main body at various heights and on various horizontal planes to obtain the measurement image of the main body;

[0026] Among them, there is an overlapping area with a preset area between the measurement images taken in adjacent poses; and a dark frame is taken between the photogrammetric scanning of the upper half and the photogrammetric scanning of the lower half to distinguish the measurement image corresponding to the upper half and the measurement image corresponding to the lower half.

[0027] Optionally, processing the measurement image to obtain a processed image, including:

[0028] Import the measurement image into the image processing software supporting the color card to batch correct the color of the measurement image;

[0029] Import the color-corrected image into the image processing software, select one of the color-corrected images to adjust the image parameters, and apply the adjustment to other color-corrected images to correct the color-corrected image obtained from this shooting to obtain a corrected measurement image;

[0030] Save the corrected measurement images corresponding to the upper half of the main body and the corrected measurement images corresponding to the lower half of the main body in different folders respectively, and export them in Jpeg format to obtain the processed image.

[0031] Optionally, generating a three-dimensional model of the main body based on the processed image in the photogrammetric model generation software, including:

[0032] Import the processed images in the folder corresponding to the upper half into the photogrammetric model generation software, automatically align the images to obtain the point cloud data of the upper half of the main body; set the reconstruction area and erase the areas that do not need to be used; use the cropping function to crop and reconstruct the model for the upper and lower parts of the support frame in the upper half to generate a depth mask map for the cropped area;

[0033] Disable all cameras in the upper part, import the processed images in the corresponding folder of the lower part, automatically align the images, and obtain the point cloud data of the lower part of the scanning model; by setting the reconstruction area, erase the areas that do not need to be used; use the cropping function to crop and reconstruct the model in the upper and lower parts of the support frame in the lower part, and generate a depth mask map for the cropped area;

[0034] Create a new modeling task in the photogrammetry model, import the corresponding folder of the upper part, the corresponding folder of the lower part, the depth mask map corresponding to the upper part, and the depth mask map corresponding to the lower part in the new modeling task, automatically align the images, and if the collected images are not completely aligned, use control points to assist the photogrammetry model generation software to align the image overlapping points to obtain the three-dimensional model of the main body.

[0035] In a second aspect, there is provided an apparatus for optimizing the accuracy of photogrammetry modeling based on cross-polarization, the apparatus including a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement the method for optimizing the accuracy of photogrammetry modeling based on cross-polarization described in the first aspect.

[0036] In a third aspect, there is provided a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by the processor to implement the method for optimizing the accuracy of photogrammetry modeling based on cross-polarization described in the first aspect.

[0037] The beneficial effects of this application are as follows:

[0038] (1) Improve the quality of three-dimensional reconstruction: By adopting the cross-polarization photogrammetry technology and using a special light source polarization accessory and a camera polarization lens, the reflection and shadow effects on the surface of the photographed object are effectively eliminated, and the quality of the photogrammetry photos is significantly improved. At the same time, a series of optimization processes such as color correction and shadow adjustment are performed on the photos, laying a solid foundation for high-precision three-dimensional reconstruction.

[0039] (2) Improve the efficiency of model reconstruction: Aiming at the problem that photo misalignment is likely to occur in the reconstruction of a complete model, a strategy of separately processing the upper and lower parts of the photographed object is adopted, combined with the depth mask map and control point alignment technology, effectively solving this problem and improving the accuracy and efficiency of model reconstruction.

[0040] (3) Generate a highly realistic model: Based on the high-resolution three-dimensional model, through post-processing such as surface correction, topology optimization, and texture reprojection, and combined with physical properties to generate normal maps, color maps, metallicity maps, and roughness maps, an optimized three-dimensional model with both high realism and low memory occupancy is finally obtained, laying a solid foundation for realizing high-quality PBR rendering.

[0041] (4) Simplify the operation process: The entire process from photogrammetry to 3D reconstruction has been systematically optimized and simplified, including the magnetic quick-release design of the polarization accessories, the integration of multi-angle shooting and depth information capture, the batch presetting of photo processing, and the stage splitting of the reconstruction process, etc. This has greatly reduced the operation threshold and workload, and improved the overall production efficiency.

[0042] (5) Wide range of application fields: The cross-polarization photogrammetry and 3D reconstruction optimization solution has strong versatility and practicality, and can be widely applied to multiple fields such as archaeological excavation, cultural relic protection, medical research, industrial manufacturing, virtual reality, etc., providing strong technical support for high-precision 3D digitization and digital twin.

[0043] (6) Low economic cost: The hardware equipment adopted is relatively simple, mainly the self-designed light source polarization accessories and camera polarization lenses, with relatively low costs. In terms of software, through algorithm optimization and parameter simplification for each link, the consumption of computing resources is effectively controlled, further reducing the economic cost.

[0044] The above description is only an overview of the technical solution of this application. In order to be able to more clearly understand the technical means of this application and implement it in accordance with the content of the specification, the following uses the preferred embodiments of this application and combines with the drawings to elaborate in detail as follows. Brief Description of the Drawings

[0045] Figure 1 It is a flowchart of an optimization method for the photogrammetry modeling accuracy based on cross-polarization provided by an embodiment of this application;

[0046] Figure 2 It is a block diagram of an optimization device for the photogrammetry modeling accuracy based on cross-polarization provided by an embodiment of this application;

[0047] Figure 3 It is a block diagram of an optimization device for the photogrammetry modeling accuracy based on cross-polarization provided by an embodiment of this application. Specific Embodiments

[0048] The following combines with the drawings and embodiments to further describe in detail the specific embodiments of this application. The following embodiments are used to illustrate this application, but are not used to limit the scope of this application.

[0049] To address the limitations of traditional photogrammetry and 3D reconstruction methods, this application proposes a new solution, namely a 3D reconstruction method based on cross-polarization accessories for photogrammetry and optimization processing. This method achieves cross-polarization shooting through self-designed light source polarization accessories and camera polarization lenses, effectively eliminating the interference of reflections and shadows on the model surface. At the same time, a series of optimization strategies such as photo preprocessing, phased modeling, surface correction, and texture reprojection are adopted to ensure the generation of a fine, realistic, and PBR material-based 3D model while improving the modeling efficiency.

[0050] However, to achieve this goal, a series of problems need to be solved, including how to design reasonable polarization accessories, how to select the best shooting parameters, how to perform efficient photo processing, how to split and optimize the modeling process, and how to generate high-quality PBR texture maps, etc. Designing polarization accessories requires considering multiple factors such as optical performance, heat dissipation, structural strength, and assembly convenience; selecting shooting parameters requires repeated testing and trade-offs in terms of light intensity, polarization angle, shooting distance, etc.; optimizing the modeling process requires reasonable stage division and the use of key technologies such as control point-assisted alignment, depth mask denoising, mesh simplification, and texture mapping; generating PBR maps requires the drawing and baking of multi-channel maps such as normal, metallicity, and roughness based on the geometric and material properties of the model.

[0051] Therefore, developing a high-quality 3D reconstruction solution based on cross-polarization photogrammetry and system optimization is a highly challenging innovative task. This requires comprehensive consideration of the theories and technologies in multiple fields such as optical imaging, image processing, 3D reconstruction, and PBR rendering, and ultimately achieves an all-round improvement in efficiency, quality, and realism through systematic experiments and optimizations.

[0052] To achieve the above goals, this application provides a comprehensive optimization solution, comprehensively applying technologies such as cross-polarization, photogrammetry, and model topology baking to effectively solve many problems that occur in photogrammetry modeling. This method has significant advantages in improving production efficiency, reducing memory occupancy, ensuring rendering quality, and maintaining visual consistency, providing important support for wide applications in fields such as topographic surveying, urban planning, architectural design, and cultural relics protection.

[0053] Figure 1 It is a flowchart of a method for optimizing the accuracy of photogrammetry modeling based on cross-polarization provided by an embodiment of this application. This method at least includes the following steps:

[0054] Step 101, design and manufacture a light source polarization component on the photogrammetry equipment based on the 3D model of the flash on the photogrammetry equipment; wherein, the light source polarization component includes a light source polarization accessory and a polarizing plate.

[0055] In this embodiment, the flash is a high-power ring flash. Since the ring flash has the best imaging effect due to its uniform illumination characteristics.

[0056] Based on the 3D model of the flash on the photogrammetry equipment, design and manufacture the light source polarization component on the photogrammetry equipment, including steps 1011-1015:

[0057] Step 1011, conduct photogrammetry on the flash to obtain the photogrammetry image of the flash.

[0058] Conducting photogrammetry on the flash includes: taking all-round shots of the flash from multiple angles to obtain the photogrammetry image of the flash. During the process of constructing the 3D model of the flash, since only the structure of the flash needs to be obtained, therefore, no additional optimization process is required for the accuracy of the 3D modeling of the flash.

[0059] Step 1012, import the photogrammetry image of the flash into 3D software for 3D reconstruction, delete the generated redundant areas, and export the primitive model of the flash to obtain the 3D model of the flash.

[0060] Step 1013, design the accessory 3D model of the light source polarization accessory adapted to the 3D model of the flash, specifically including:

[0061] Design the accessory 3D model of the light source polarization accessory adapted to the 3D model of the flash, including: using the hollowing process to design the accessory 3D model; setting multiple holes on the inner side of the accessory 3D model to inlay magnet blocks, and the iron blocks are used to quickly assemble the light source polarization accessory with the flash.

[0062] Among them, the number of holes can be 8-12 holes. In other embodiments, the number of holes can also be more or less. This embodiment does not limit the number of holes.

[0063] Since a large amount of heat is generated when the high-power high-speed flash operates, therefore, using the hollowing process in the design of the accessory can ensure the heat dissipation and stability of the light source polarization accessory.

[0064] Step 1014, use a 3D printer to manufacture the light source polarization accessory based on the accessory 3D model.

[0065] Specifically, convert the accessory 3D model to the Stl format, print it in the 3D printer using black nylon carbon fiber material, and polish the printed finished product with sandpaper to obtain the light source polarization accessory.

[0066] Step 1015: Based on the assembly space at the first assembly position on the light source polarization accessory, cut the polarizer to obtain a polarizer adapted to the assembly space, and assemble the cut polarizer into the light source polarization accessory through the first assembly position to obtain a light source polarization assembly.

[0067] In one example, cut the polarizer according to the size of the inner groove ring of the accessory and the size of the vacant position, and assemble the polarizer into the light source polarization accessory. Install magnets at the reserved hole position of the polarization accessory and at the contact position with the ring flash respectively, and fix them with AB glue. Assemble the polarization accessory onto the flash body by magnetic attraction.

[0068] Step 102: Install the light source polarization assembly on the flash and the camera lens of the photogrammetry equipment respectively, and perform photogrammetry scanning on the subject to be three-dimensionally reconstructed based on the cross-polarization technology to obtain the measurement image of the subject.

[0069] In one example, performing photogrammetry scanning on the subject to be three-dimensionally reconstructed based on the cross-polarization technology to obtain the measurement image of the subject includes steps 1021 - 1023:

[0070] Step 1021: Adjust the flash power to full power and set the format of the measurement image to Raw.

[0071] Install the light source polarization accessory and the polarizing lens on the flash and the camera lens respectively, and adjust the flash power to full power.

[0072] Step 1022: Perform photogrammetry scanning on the upper half and the lower half of the subject respectively based on the cross-polarization technology to obtain the measurement image of the subject.

[0073] Specifically, performing photogrammetry scanning on the upper half and the lower half of the subject respectively based on the cross-polarization technology to obtain the measurement image of the subject includes: when performing photogrammetry scanning on each part respectively, keep the physical distance between the photogrammetry equipment and the subject unchanged, take photos of the subject on various heights and various horizontal planes to obtain the measurement image of the subject.

[0074] Among them, there is an overlapping area with a preset area between the measurement images taken in adjacent poses; and a dark frame is taken between the photogrammetry scanning of the upper half and the photogrammetry scanning of the lower half to distinguish the measurement image corresponding to the upper half and the measurement image corresponding to the lower half.

[0075] After completing one cycle of shooting, raise the height of the camera and perform another cycle of shooting for the subject. After completing the shooting, cover the lens cap and take a dark frame to ensure that the upper and lower part photos can be easily distinguished later.

[0076] In one example, the upper half is photographed first, and then the lower half is photographed. When photographing the lower half of the subject, the subject is turned over to ensure that no deformation occurs to the subject during the turning process.

[0077] The preset area can be 50%-60%. In other embodiments, the value of the preset area can also be other values, and the present embodiment does not limit the value of the preset area.

[0078] During the photographing process, the following photographing conditions are available: 1. During the photographing process, the camera is not only rotated up and down at the same position to take pictures in the same place, but the position of the camera is moved and changed for photographing; 2. Silent shooting or electronic shutter is not used to avoid problems that the jelly effect affects the generation quality; 3. Avoid using video to replace photos.

[0079] In addition, a photogrammetry device without a light source polarization component can also be used to separately perform photogrammetry scanning on the upper half and the lower half of the subject to obtain a comparison image of the subject. At this time, when observing the comparison image and the measurement image, it can be found that there are obvious reflection and shadow effects on the surface of the subject in the comparison image, while there are no obvious reflection and shadow effects in the measurement image, and the color restoration effect is much better than that of the comparison image.

[0080] Step 1023: Place the color card in the same light and shadow environment of the subject, and photograph the color card based on the cross-polarization technology.

[0081] Step 103: Process the measurement image to obtain a processed image.

[0082] Processing the measurement image to obtain a processed image includes steps 1031-1033:

[0083] Step 1031: Import the measurement image into the image processing software supporting the color card to batch-correct the color of the measurement image.

[0084] To batch-correct the color of the measurement image includes: optimizing the color difference problems such as color, white balance, and lightness of the measurement image caused by light.

[0085] Step 1032: Import the color-corrected image into the image processing software (such as Adobe Lightroom), select one of the color-corrected images to adjust the image parameters, and apply the adjustment to other color-corrected images to correct the color-corrected image obtained from this shooting to obtain a corrected measurement image.

[0086] Among them, the image parameters include but are not limited to: the shadow of the image, as well as parameters such as brightness and exposure. The content of the image parameters is not limited in this embodiment. The color scale of the corrected measurement image is flatter than that of the color-corrected image.

[0087] It should be noted that during the image correction process, avoid AI intelligent sampling operations. Improving the resolution of AI intelligent sampling cannot improve the generation effect, but will make it worse.

[0088] Step 1032: Save the corrected measurement images corresponding to the upper half and the lower half of the subject in different folders respectively, and export them in Jpeg format to obtain the processed images.

[0089] The naming of the folder corresponding to the upper half is different from that of the folder corresponding to the lower half. For example, the naming of the folder corresponding to the upper half is Top, and the naming of the folder corresponding to the lower half is Botten.

[0090] Step 104: Generate a three-dimensional model of the subject based on the processed images in the photogrammetry model generation software.

[0091] In one example, in the photogrammetry model generation software, generating a three-dimensional model of the subject based on the processed images includes steps 1041 - 1043:

[0092] Step 1041: Import the processed images in the folder corresponding to the upper half into the photogrammetry model generation software, automatically align the images to obtain the point cloud data of the upper half of the subject; set the reconstruction area to erase the areas that do not need to be used; use the cropping function to crop and reconstruct the model for the upper and lower parts of the support frame in the upper half, and generate a depth mask map for the cropped area.

[0093] In this embodiment, the camera depth should be exported simultaneously when exporting the depth mask map.

[0094] Step 1042: Disable all cameras in the upper half, import the processed images in the folder corresponding to the lower half, automatically align the images to obtain the point cloud data of the lower half of the scan model; by setting the reconstruction area, erase the areas that do not need to be used; use the cropping function to crop and reconstruct the model for the upper and lower parts of the support frame in the lower half, and generate a depth mask map for the cropped area.

[0095] Step 1043: Create a new modeling task in the photogrammetry model. Import the folders corresponding to the upper part, the folders corresponding to the lower part, the depth mask texture maps corresponding to the upper part, and the depth mask texture maps corresponding to the lower part into the new modeling task, and automatically align the images. If the collected images are not completely aligned, use control points to assist the photogrammetry model generation software to align the image overlap points to obtain the three-dimensional model of the subject.

[0096] Optionally, if photogrammetry equipment without a light source polarization component can also be used to perform photogrammetry scans on the upper and lower parts of the subject respectively to obtain comparison images of the subject, the comparison images of the subject can also be processed through Steps 103 and 104 to obtain a comparison model of the subject. At this time, when observing the comparison model and the three-dimensional model of the subject, it is found that there are many bumps generated by noise on the surface of the comparison model, and there are many overexposed or underexposed effects caused by natural light irradiation on the generated texture maps. The surface of the three-dimensional model of the subject is smooth, and the generated texture maps are not baked with natural light.

[0097] Step 105: Optimize the three-dimensional model of the subject to obtain a model generated by photogrammetry of the subject.

[0098] Optionally, optimizing the three-dimensional model of the subject to obtain a model generated by photogrammetry of the subject includes Steps 1051 - 1055:

[0099] Step 1051: Export the high-resolution model from the photogrammetry model generation software and export it to the Zbrush software to polish and correct the surface of the three-dimensional model of the subject.

[0100] Although the cross-polarization technology is used to collect test images, the scanning effect for some high-brightness materials such as metals is still not satisfactory. In this embodiment, by further optimizing the three-dimensional model of the subject, the reconstruction effect of the three-dimensional model of the subject can be further improved.

[0101] Step 1052: Import the corrected high-resolution model back into the photogrammetry model generation software (ensuring that the position and scale of the model remain unchanged during this process); fill in the upper limit of the number of polygons in the simplification function to perform topology on the high-resolution model to generate a low-resolution model.

[0102] Step 1053: Use the texture reprojection tool on the high-resolution model, set the resolution to 8K, and map the texture map to the high-resolution model.

[0103] Step 1054: Use the texture reprojection tool again, set the high-resolution model as the source model, and the low-resolution model as the target model to generate a normal map and a color map;

[0104] Step 1055: Import the source model and the object model into the texture mapping software. Draw the metallic and roughness textures according to the material properties of the models, and control the intensity by grayscale values to obtain the model generated by photogrammetry.

[0105] At this point, the model generated by photogrammetry can be used in any 3D software. It not only retains extremely high authenticity but also does not occupy too much memory.

[0106] In summary, the method for optimizing the accuracy of photogrammetric modeling based on cross-polarization provided in this embodiment has the following beneficial effects:

[0107] (1) Improve the quality of 3D reconstruction: By using cross-polarization photogrammetry technology and special light source polarization accessories and camera polarization lenses, the reflection and shadow effects on the surface of the object being photographed are effectively eliminated, significantly improving the quality of photogrammetry photos. At the same time, a series of optimization processes such as color correction and shadow adjustment are performed on the photos, laying a solid foundation for high-precision 3D reconstruction.

[0108] (2) Improve the efficiency of model reconstruction: Aiming at the problem of misalignment of photos that is likely to occur in the reconstruction of a complete model, the strategy of separately processing the upper and lower halves of the object being photographed is adopted, combined with depth mask texture and control point alignment technology, effectively solving this problem and improving the accuracy and efficiency of model reconstruction.

[0109] (3) Generate a highly realistic model: Based on a high-resolution 3D model, through post-processing such as surface correction, topology optimization, and texture reprojection, and combined with physical properties to generate normal maps, color maps, metallic maps, and roughness maps, an optimized 3D model with both high realism and low memory occupancy is finally obtained, laying a solid foundation for achieving high-quality PBR rendering.

[0110] (4) Simplify the operation process: The entire process from photogrammetry to 3D reconstruction has been systematically optimized and simplified, including the magnetic quick-release design of polarization accessories, the integration of multi-angle shooting and depth information capture, the batch presetting of photo processing, and the stage splitting of the reconstruction process, greatly reducing the operation threshold and workload and improving the overall production efficiency.

[0111] (5) Wide range of application fields: The cross-polarization photogrammetry and 3D reconstruction optimization scheme has strong versatility and practicality, and can be widely applied to multiple fields such as archaeological excavation, cultural relic protection, medical research, industrial manufacturing, virtual reality, etc., providing strong technical support for high-precision 3D digitization and digital twin.

[0112] (6) Low economic cost: The hardware devices adopted are relatively simple, mainly the independently designed light source polarization accessories and camera polarization lenses, with relatively low costs. In terms of software, through algorithm optimization and parameter simplification in each link, the consumption of computing resources is effectively controlled, further reducing the economic cost.

[0113] Figure 2 It is a block diagram of an apparatus for optimizing the accuracy of photogrammetric modeling based on cross polarization provided by an embodiment of the present application. The apparatus at least includes the following several modules: a component manufacturing module 210, an image measurement module 220, an image processing module 230, a model generation module 240, and a model optimization module 250.

[0114] The component manufacturing module 210 is used to design and manufacture a light source polarization component on the photogrammetric equipment based on the three-dimensional model of the flash on the photogrammetric equipment; wherein, the light source polarization component includes a light source polarization accessory and a polarizing plate;

[0115] The image measurement module 220 is used to respectively install the light source polarization component on the flash and the camera lens of the photogrammetric equipment, and perform photogrammetric scanning on the subject to be three-dimensionally reconstructed based on the cross polarization technology to obtain a measurement image of the subject;

[0116] The image processing module 230 is used to process the measurement image to obtain a processed image;

[0117] The model generation module 240 is used to generate a three-dimensional model of the subject in the photogrammetric model generation software based on the processed image;

[0118] The model optimization module 250 is used to optimize the three-dimensional model of the subject to obtain a model generated by photogrammetry of the subject.

[0119] For relevant details, refer to the above method embodiment.

[0120] It should be noted that: when the apparatus for optimizing the accuracy of photogrammetric modeling based on cross polarization provided in the above embodiment performs the optimization of the accuracy of photogrammetric modeling based on cross polarization, only the above division of each functional module is used for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the apparatus for optimizing the accuracy of photogrammetric modeling based on cross polarization is divided into different functional modules to complete all or part of the above-described functions. In addition, the apparatus for optimizing the accuracy of photogrammetric modeling based on cross polarization provided in the above embodiment and the method embodiment for optimizing the accuracy of photogrammetric modeling based on cross polarization belong to the same concept. For the specific implementation process, refer to the method embodiment, and details are not described here again.

[0121] Figure 3 FIG. Figure 3 is a block diagram of a device for optimizing the accuracy of photogrammetric modeling based on cross-polarization provided by an embodiment of the present application. The device may be a smart phone, a tablet computer, a laptop computer, a desktop computer, a server, or the like. The device for optimizing the accuracy of photogrammetric modeling based on cross-polarization may also be referred to as a user equipment, a portable terminal, a laptop terminal, a desktop terminal, a control terminal, etc., and this embodiment does not limit this. The device at least includes a processor 301 and a memory 302.

[0122] The processor 301 may include one or more processing cores, such as: a 4-core processor, an 8-core processor, etc. The processor 301 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 301 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as the CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 301 may be integrated with a GPU (Graphics Processing Unit), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 301 may further include an AI (Artificial Intelligence) processor, and the AI processor is used to process computational operations related to machine learning.

[0123] The memory 302 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 302 may further include a high-speed random access memory and a non-volatile memory, such as one or more disk storage devices and flash storage devices. In some embodiments, the non-transitory computer-readable storage media in the memory 302 is used to store at least one instruction, and the at least one instruction is used to be executed by the processor 301 to implement the method for optimizing the accuracy of photogrammetric modeling based on cross-polarization provided by the method embodiment of the present application.

[0124] In some embodiments, the apparatus for optimizing the accuracy of photogrammetric modeling based on cross-polarization may optionally further include: a peripheral device interface and at least one peripheral device. The processor 301, the memory 302, and the peripheral device interface may be connected through a bus or signal lines. Each peripheral device may be connected to the peripheral device interface through a bus, signal lines, or a circuit board. Schematically, the peripheral devices include, but are not limited to: a radio frequency circuit, a touch display screen, an audio circuit, and a power supply, etc.

[0125] Of course, the apparatus for optimizing the accuracy of photogrammetric modeling based on cross-polarization may also include fewer or more components, and this embodiment does not limit this.

[0126] Optionally, the present application also provides a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the method for optimizing the accuracy of photogrammetric modeling based on cross-polarization in the above method embodiments.

[0127] Optionally, the present application also provides a computer product, which includes a computer-readable storage medium, in which a program is stored, and the program is loaded and executed by a processor to implement the method for optimizing the accuracy of photogrammetric modeling based on cross-polarization in the above method embodiments.

[0128] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0129] The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for optimizing the accuracy of photogrammetric modeling based on cross polarization, characterized in that: The method comprises: Based on the three-dimensional model of the flash on the photogrammetry equipment, design and manufacture the light source polarization component on the photogrammetry equipment; wherein the light source polarization component includes a light source polarization accessory and a polarizer; The light source polarization component is respectively mounted on the flash and the camera lens of the photogrammetric equipment to perform photogrammetric scanning on the subject to be three-dimensionally reconstructed based on the cross-polarization technology to obtain a measurement image of the subject, including: The flash power is adjusted to full power, and the format of the measurement image is set to Raw; Performing photogrammetric scanning on the upper half and the lower half of the subject respectively based on the cross-polarization technique to obtain a measurement image of the subject; Place the color card in the same light and shadow environment as the subject, and shoot the color card based on the cross-polarization technology; The method of performing photogrammetric scanning on the upper and lower parts of the subject based on the cross-polarization technology to obtain a measurement image of the subject includes: When performing photogrammetric scanning on each part, the physical distance between the photogrammetric equipment and the subject is kept constant, and photographs are taken of the subject at various heights and levels to obtain a measurement image of the subject; There is an overlap area of ​​a preset area between the measurement images captured in adjacent positions; and a dark frame is captured between the photogrammetric scan of the upper half and the photogrammetric scan of the lower half to distinguish the measurement image corresponding to the upper half from the measurement image of the lower half; Processing the measured image to obtain a processed image includes: Importing the measured images into image processing software matched with the color card to perform batch color calibration on the measured images; Importing the color-calibrated images into image processing software, selecting one of the color-calibrated images to adjust image parameters, and applying the adjustment to other color-calibrated images to correct the color-calibrated image obtained in this shooting, thereby obtaining a corrected measurement image; The corrected measurement image corresponding to the upper half of the subject and the corrected measurement image corresponding to the lower half are saved in different folders, respectively, and exported to Jpeg format to obtain processed images; In the photogrammetry model generation software, generating a three-dimensional model of the subject based on the processed image includes: Import the processed images in the folder corresponding to the upper part into the photogrammetry model generation software, automatically align the images, and obtain the point cloud data of the upper part of the subject; set the reconstruction area and erase the unnecessary area; use the cropping function to crop the upper and lower parts of the support frame in the upper part and reconstruct the model to generate a depth mask map of the cropped area; Disable all cameras in the upper part, import the processed images in the folder corresponding to the lower part, automatically align the images, and obtain the point cloud data of the lower part of the scanned model; set the reconstruction area to erase the unnecessary area; use the cropping function to crop the upper and lower parts of the support frame in the lower part and reconstruct the model to generate a depth mask map of the cropped area; Creating a new modeling task in the photogrammetry model, importing the folder corresponding to the upper half, the folder corresponding to the lower half, the depth mask map corresponding to the upper half, and the depth mask map corresponding to the lower half into the new modeling task, automatically aligning the images, and if the images of the set are not completely aligned, using control points to assist the photogrammetry model generation software to align the image overlap points, so as to obtain a three-dimensional model of the subject; The three-dimensional model of the subject is optimized to obtain a model generated by photogrammetry of the subject.

2. The method according to claim 1, characterized in that: The method of designing and manufacturing a light source polarization component on the photogrammetry equipment based on the three-dimensional model of the flash on the photogrammetry equipment includes: Performing photogrammetry on the flashlight to obtain a photogrammetry image of the flashlight; Importing the photogrammetric image of the flashlight into a three-dimensional software for three-dimensional reconstruction, deleting the generated redundant area, exporting the plain model of the flashlight, and obtaining the three-dimensional model of the flashlight; Designing a three-dimensional model of a light source polarization accessory that matches the three-dimensional model of the flashlight; The light source polarization accessory is manufactured based on the three-dimensional model of the accessory by a 3D printer; Based on the assembly space of the first assembly position on the light source polarization accessory, the polarizer is cut to obtain a polarizer adapted to the assembly space, and the cut polarizer is assembled to the light source polarization accessory through the first assembly position to obtain the light source polarization component.

3. The method according to claim 2, characterized in that The accessory three-dimensional model of the light source polarization accessory designed to match the three-dimensional model of the flashlight includes: Designing the three-dimensional model of the accessory using a hollowing process; A plurality of holes are arranged inside the three-dimensional model of the accessory to embed a magnet block, and the iron block is used to quickly assemble the light source polarization accessory and the flashlight.

4. The method according to any one of claims 1 to 3, characterized in that: The step of optimizing the three-dimensional model of the subject to obtain a model generated by photogrammetry of the subject includes: Exporting a high-resolution model from the photogrammetry model generation software to Zbrush software to perform polishing correction on the surface of the three-dimensional model of the subject; Importing the corrected high-resolution model back into the photogrammetry model generation software; filling in the upper limit of the number of polygons in the simplification function, topologically performing the high-resolution model, and generating a low-resolution model; Use the texture reprojection tool on the high-resolution model, set the resolution to 8K, and map the texture map onto the high-resolution model; Use the texture reprojection tool again, set the high-resolution model as the source model and the low-resolution model as the object model, and generate a normal map and a color map; The source model and the object model are imported into the texture drawing software, and the metalness and roughness maps are drawn according to the material characteristics of the model, and the intensity is controlled by the grayscale value to obtain the model generated by the photogrammetry.

5. A device for optimizing the accuracy of photogrammetric modeling based on cross polarization, characterized in that: The device includes a processor and a memory; a program is stored in the memory, and the program is loaded and executed by the processor to implement the cross-polarization based photogrammetry modeling accuracy optimization method as described in any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that: The storage medium stores a program, which, when executed by a processor, is used to implement the cross-polarization-based photogrammetry modeling accuracy optimization method as described in any one of claims 1 to 4.

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