Stone stone carving digital rubbing method based on three-dimensional laser scanning model

Abstract

The invention discloses a stele stone carving digital rubbing method based on a three-dimensional laser scanning model, and relates to the technical field of cultural relic protection and digitization, and the method comprises the steps: scanning a stele by using a three-dimensional data scanner, obtaining the three-dimensional data of the stele, and carrying out the data splicing to form a three-dimensional data set; preprocessing the three-dimensional data set and constructing a three-dimensional surface model of the stele; extracting a grey-scale map of the surface of the stele from the three-dimensional surface model; and gray information of the concave seam area on the surface of the stele is extracted from the gray-scale map, and a digital rubbing of the stele is generated according to the gray information. Complete three-dimensional data of the stele is obtained by using a three-dimensional laser scanner, the integrity of the data is ensured, a three-dimensional surface model is generated by using an advanced algorithm, the geometric accuracy of the model is ensured, an accurate basis is provided for the extraction of a grey-scale map, the extracted concave seam area information is more accurate, the definition and detail expressive force of the image are enhanced, and the image quality is improved. And the finally generated digital rubbing has high resolution and high contrast.

Description

Technical Field

[0001] The invention relates to the technical field of cultural relics protection and digitization, in particular to a method for digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model. Background Art

[0002] With the rapid development of computer graphics and 3D measurement technology, 3D laser scanning technology has gradually become an important tool in the fields of cultural relics protection, building measurement and industrial inspection. 3D laser scanners can obtain complete 3D data of the surface of objects in a high-precision, non-contact manner, especially on objects with complex surfaces or rich textures. In the field of cultural relics protection, the traditional rubbing technology has a long history and can retain certain cultural values ​​and skills, but its contact production method often causes certain damage to the surface of cultural relics, especially in the process of rubbing stone tablets and stone carvings, because it is necessary to repeatedly apply pressure and medium, it is easy to accelerate the weathering and aging of stone materials. Therefore, with the development of 3D laser scanning technology, its application in the digital processing of stone tablets and stone carvings not only improves the measurement accuracy, but also can fully record the details of its surface without contacting the cultural relics, providing a reliable foundation for subsequent digital rubbing and research.

[0003] However, the existing technology still has some limitations in the process of using three-dimensional laser scanning to generate digital rubbings. Traditional methods often rely on texture mapping technology to combine the three-dimensional data of the stone tablet surface with the two-dimensional image to generate a rubbing effect. Texture mapping technology is prone to errors when processing the complex texture and subtle grooves on the surface of the stone tablet, resulting in the quality and accuracy of the rubbings cannot be fully guaranteed. The existing technology uses two-dimensional image processing technology to generate electronic rubbings, which is difficult to fully utilize the high-precision three-dimensional data obtained by three-dimensional laser scanning, resulting in insufficient restoration of the rubbing details, especially in terms of the depth and subtle differences in the groove area. In the process of data splicing and processing, the existing methods may lead to inaccurate three-dimensional model construction due to the lack of systematic optimization algorithms, further affecting the quality of the final digital rubbings. How to make full use of three-dimensional laser scanning technology, combined with advanced image processing algorithms, to generate high-precision and high-fidelity digital rubbings without damaging cultural relics is still a key problem in the development of technology in this field. Summary of the invention

[0004] In view of the problems existing in the above-mentioned existing method of digital rubbing of stone tablets and stone carvings based on three-dimensional laser scanning models, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is that the existing three-dimensional laser scanning technology has problems such as large texture mapping errors, inability to fully restore details, and inaccurate data processing in the application of digital rubbings of stone tablets and stone carvings.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model, which comprises:

[0007] Scan the stone tablet using a three-dimensional data scanner to obtain the three-dimensional data of the stone tablet and perform data splicing to form a three-dimensional data set;

[0008] Preprocess the 3D data set and construct a 3D surface model of the stele;

[0009] Extract the grayscale image of the stele surface from the three-dimensional surface model;

[0010] Extracting grayscale information of the concave seam area on the surface of the stone tablet from the grayscale image, and generating a digital rubbing of the stone tablet according to the grayscale information;

[0011] All relevant data are archived and stored, and the archived data files are integrated into the central data management system for cross-terminal visualization operations.

[0012] As a preferred solution of the method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model of the present invention, wherein: the use of a three-dimensional data scanner to scan the stone tablet and obtain the three-dimensional data of the stone tablet refers to selecting a high-precision three-dimensional laser scanner, performing preliminary settings of the equipment according to scanning requirements, the preliminary settings of the equipment including calibration of the three-dimensional laser scanner and setting of scanning parameters, and selecting multiple scanning positions according to the size and shape of the stone tablet;

[0013] Starting the 3D laser scanner, and sequentially acquiring 3D data of each scanning position of the stone tablet according to the selected multiple scanning positions, and storing the 3D data in the internal memory of the 3D laser scanner after each scanning is completed;

[0014] After all scan locations are scanned, transfer the data to the computer via Wi-Fi.

[0015] As a preferred scheme of the method for digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model described in the present invention, the data splicing to form a three-dimensional data set refers to using the automatic alignment function of the three-dimensional scanning software in the computer to align and splice the three-dimensional data of multiple scanning positions for the first time according to the built-in positioning information of the three-dimensional data scanner to form a complete three-dimensional data set.

[0016] As a preferred solution of the method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model of the present invention, wherein: the preprocessing of the three-dimensional data set and construction of the three-dimensional surface model of the stone tablet refers to preprocessing the three-dimensional data set, including using a Gaussian filter to denoise the three-dimensional data, and using a K-means clustering method to remove abnormal data points in the three-dimensional data set;

[0017] Import the preprocessed 3D data set into the 3D modeling software;

[0018] Based on the geometric features of the stone tablet surface, the feature points in the 3D data set are defined. The feature points include the sharp corners, corners and edges of the carved text on the stone tablet surface. The ICP algorithm is used to perform a second alignment and splicing of all the 3D data in the 3D data set based on the defined feature points.

[0019] According to the aligned and spliced ​​3D data sets, a 3D surface model is generated using the Delaunay triangulation algorithm, and the generated 3D surface model is refined, including adjusting the mesh edge length and applying the Laplacian smoothing algorithm to reduce the surface sharpness and smooth the model;

[0020] Use Geomagic Design X topology analysis tools in 3D modeling software to automatically detect and repair topological defects in models;

[0021] The Geomagic Control X error analysis tool is used to compare the 3D surface model with the original 3D data to generate an error distribution map.

[0022] By analyzing the error distribution map, local deviations and defects in the 3D surface model are identified. Based on the identified local deviations and defects, the 3D surface model is refined again. By manually adjusting the 3D surface model, the surface of the model is pulled and pushed to fill the defects of the model.

[0023] As a preferred solution of the method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model of the present invention, wherein: the grayscale image of the stone tablet surface is extracted from the three-dimensional surface model, which refers to manually selecting the concave seam boundary of the stone tablet surface in the three-dimensional surface model by using a brush tool of a three-dimensional modeling software, wherein the concave seam boundary includes the concave part of the inscription and the engraved line, and automatically adjusting the selected concave seam boundary by using an adaptive filtering algorithm by analyzing the depth difference between the shallowest point and the deepest point of the manually selected concave seam boundary;

[0024] A mask is generated based on the self-adaptively adjusted concave seam boundary, the boundary of the mask is manually adjusted, and the grayscale value of each pixel in the mask is determined according to the depth difference of the concave seam boundary by a grayscale conversion algorithm;

[0025] Generate a grayscale image based on the grayscale value of each pixel in the mask, and use the histogram equalization in the contrast enhancement algorithm to increase the difference between the dark and light areas in the grayscale image;

[0026] The enhanced grayscale image is subjected to noise removal, and a Gaussian filter is used to smooth the image and eliminate subtle noise.

[0027] As a preferred solution of the method for digital rubbing of stone tablets and stone carvings based on the three-dimensional laser scanning model of the present invention, wherein: the grayscale information of the concave seam area on the surface of the stone tablet is extracted from the grayscale image, and the digital rubbing of the stone tablet is generated according to the grayscale information, which means that the grayscale image is converted into a binary image using PS image processing software, and the optimal threshold is automatically determined by Otsu's threshold segmentation method, and the pixels in the grayscale image are divided into black and white, with the concave seam area being black and the other areas being white;

[0028] The Canny edge detection algorithm is used to calculate the gradient of the binary image, detect the concave seam boundary, and extract the concave seam contour in the binary image as the digital rubbing. The non-maximum suppression algorithm is used to refine the edge lines of the digital rubbing.

[0029] Use the repair brush tool to repair the digital rubbing;

[0030] Make global adjustments to digital rubbings, including levels, brightness, and contrast adjustments;

[0031] Perform color correction on digital rubbings according to display requirements;

[0032] Use ImageMagick image verification tool to verify the generated digital rubbings.

[0033] As a preferred solution of the method for digital rubbings of stone tablets and stone carvings based on three-dimensional laser scanning models described in the present invention, the archiving, organization and storage of all relevant data refers to creating independent folders for each type of data after generating digital rubbings, archiving all relevant data, including original three-dimensional data, three-dimensional surface models, processed grayscale images and digital rubbings, using a unified naming rule, and storing the archived data files in a storage device.

[0034] As a preferred solution of the method for digital rubbings of stone tablets and stone carvings based on three-dimensional laser scanning models described in the present invention, the integration of archived data files into the central data management system for cross-terminal visualization operations refers to integrating the archived data files into the central data management system, connecting the data files and the database of the central data management system using a RESTful API interface, assigning different access rights to users of different levels, integrating WelGL technology, embedding the three-dimensional surface model and digital rubbings into the front-end interface of the system, and allowing users to perform cross-terminal visualization operations.

[0035] A computer device comprises: a memory and a processor; the memory stores a computer program, characterized in that: when the processor executes the computer program, the method of digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model is implemented.

[0036] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the method of implementing digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model is implemented.

[0037] The beneficial effects of the present invention are: using a three-dimensional laser scanner to obtain the complete three-dimensional data of the stone tablet, ensuring the integrity of the data, using advanced algorithms to generate a three-dimensional surface model, ensuring the geometric accuracy of the model, providing an accurate basis for the extraction of grayscale images, making the extracted concave seam area information more accurate, enhancing the clarity and detail expression of the image, and making the final digital rubbing have high resolution and high contrast. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use 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 ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0039] Figure 1 The figure is a flow chart of a method for digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model.

[0040] Figure 2 Schematic diagram of the process of generating digital rubbings of stone tablets. DETAILED DESCRIPTION

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0044] Example 1

[0045] Reference Figure 1 and Figure 2, which is the first embodiment of the present invention, and provides a method for digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model. The method for digital rubbings of stone tablets and stone carvings based on a three-dimensional laser scanning model comprises the following steps:

[0046] S1. Scan the stone tablet using a three-dimensional data scanner to obtain three-dimensional data of the stone tablet and perform data splicing to form a three-dimensional data set;

[0047] Specifically, scanning the stele with a three-dimensional data scanner to obtain three-dimensional data of the stele means selecting a high-precision three-dimensional laser scanner, performing preliminary settings of the equipment according to scanning requirements, the preliminary settings of the equipment including calibration of the three-dimensional laser scanner and setting of scanning parameters, and selecting multiple scanning positions according to the size and shape of the stele;

[0048] Starting the 3D laser scanner, and sequentially acquiring 3D data of each scanning position of the stone tablet according to the selected multiple scanning positions, and storing the 3D data in the internal memory of the 3D laser scanner after each scanning is completed;

[0049] After all scan locations are scanned, transfer the data to the computer via Wi-Fi.

[0050] By using a high-precision 3D laser scanner and selecting multiple scanning positions according to the size and shape of the stele, we ensure that the 3D data of the stele surface is fully captured. Through the initial setup and precise calibration of the equipment, the accuracy and consistency of data acquisition are improved. After the scan is completed, the data is stored in the internal memory and transmitted to the computer via Wi-Fi, realizing efficient data transmission and storage, ensuring the integrity and accuracy of the stele's 3D data, and laying a solid foundation for subsequent modeling and analysis.

[0051] Furthermore, data splicing to form a 3D data set means that according to the built-in positioning information of the 3D data scanner, the 3D data of multiple scanning positions are aligned and spliced ​​for the first time using the automatic alignment function of the 3D scanning software in the computer to form a complete 3D data set. When scanning a stone tablet, since the stone tablet needs to be scanned from multiple angles or positions, the data at each position will have an independent coordinate system and perspective. In order to integrate the 3D data obtained from these different positions into a complete 3D data set, these data need to be aligned and spliced ​​for the first time.

[0052] Through the automatic alignment function of the 3D scanning software and the built-in positioning information of the 3D data scanner, the 3D data from multiple scanning positions are aligned and spliced ​​for the first time, successfully integrating the 3D data from different angles and positions to form a complete 3D data set, ensuring the uniformity and continuity of the data, avoiding coordinate deviation and error accumulation from different perspectives, and providing a solid foundation for subsequent accurate 3D modeling.

[0053] S2, preprocessing the three-dimensional data set and constructing a three-dimensional surface model of the stone tablet;

[0054] Specifically, preprocessing the three-dimensional data set and constructing the three-dimensional surface model of the stone tablet refers to preprocessing the three-dimensional data set, including using a Gaussian filter to perform denoising on the three-dimensional data, and using a K-means clustering method to remove abnormal data points in the three-dimensional data set;

[0055] Import the preprocessed 3D data set into the 3D modeling software;

[0056] Geometric features refer to the parts of the stone tablet surface with significant structural or morphological changes. These parts have specific geometric properties in the 3D data set and can be used to accurately align and build models. According to the geometric features of the stone tablet surface, the feature points in the 3D data set are defined. The feature points include the sharp corners, corners and edges of the carved text on the stone tablet surface. The ICP algorithm is used to perform a second alignment and splicing of all 3D data in the 3D data set based on the defined feature points. In the 3D modeling process, even if the data has been preliminarily aligned and spliced, further alignment is still required due to the complex geometric features that may exist on the stone tablet surface, so as to ensure that all 3D data can accurately reflect the true morphology of the stone tablet surface when generating the model;

[0057] Based on the aligned and spliced ​​3D data sets, a 3D surface model is generated using the Delaunay triangulation algorithm. The Delaunay triangulation algorithm is an algorithm used in computational geometry to divide a set of points in a plane or 3D space into a series of non-overlapping triangles and tetrahedrons. The generated 3D surface model is refined, including adjusting the mesh edge length and applying the Laplacian smoothing algorithm to reduce the surface sharpness and smooth the model. The Laplacian smoothing algorithm is an algorithm used to smooth 3D meshes or surfaces. It adjusts the position of mesh vertices to make the surface smoother and flatter while maintaining the original geometric features as much as possible.

[0058] Automatically detect and repair topological defects in models using the Geomagic Design X topology analysis tool in the 3D modeling software. Geomagic Design X can detect and repair topological problems in 3D surface models.

[0059] The Geomagic Control X error analysis tool compares the 3D surface model with the original 3D data to generate an error distribution map. Geomagic Control X provides the function of deviation analysis.

[0060] By analyzing the error distribution map, local deviations and defects in the 3D surface model are identified. Based on the identified local deviations and defects, the 3D surface model is refined again. By manually adjusting the 3D surface model, the surface of the model is pulled and pushed to fill the defects of the model.

[0061] The purity and accuracy of the data were ensured by preprocessing the 3D data set, including using Gaussian filter denoising and K-means clustering to remove abnormal data points. The ICP algorithm was used to accurately align and splice the geometric features of the stele to ensure that the 3D data fully and accurately reflected the true shape of the stele. The 3D surface model generated by the Delaunay triangulation algorithm was smoother and retained key features after optimization by the Laplacian smoothing algorithm. Topological defect repair and error analysis were performed using Geomagic Design X and Geomagic Control X to further improve the accuracy and reliability of the model. The error distribution map was used to identify and correct local deviations, making the model closer to the actual shape of the stele, thereby ensuring that the final 3D model was of high accuracy and quality, providing a solid technical foundation for the digital preservation and subsequent application of the stele.

[0062] S3, extracting a grayscale image of the stone tablet surface from the three-dimensional surface model;

[0063] Specifically, extracting the grayscale image of the stone tablet surface from the three-dimensional surface model means manually selecting the concave seam boundary of the stone tablet surface in the three-dimensional surface model by using the brush tool of the three-dimensional modeling software, the concave seam boundary includes the sunken part of the inscription and the engraved line, and automatically adjusting the selected concave seam boundary by using an adaptive filtering algorithm by analyzing the depth difference between the shallowest point and the deepest point of the manually selected concave seam boundary. The adaptive filter will be adjusted according to the local characteristics of the data, and different filtering strengths will be applied in different areas to effectively suppress noise or adjust the signal while retaining useful information;

[0064] Generate a mask based on the self-adaptively adjusted concave seam boundary, manually adjust the mask boundary so that the mask covers the concave seam area, and determine the grayscale value of each pixel in the mask according to the depth difference of the concave seam boundary through the grayscale conversion algorithm. The grayscale conversion algorithm processes the depth data to express the detail information of different heights of the object surface in the form of grayscale, so that the deeper concave area and the shallower area show different brightness differences in the grayscale image;

[0065] Generate a grayscale image based on the grayscale value of each pixel in the mask, and use the histogram equalization in the contrast enhancement algorithm to increase the difference between dark and light areas in the grayscale image. Histogram equalization is used to increase the brightness difference between different areas in the image, making the details of the image clearer and easier to identify;

[0066] The enhanced grayscale image is subjected to noise removal, and a Gaussian filter is used to smooth the image and eliminate subtle noise.

[0067] By extracting the grayscale image of the stele surface from the 3D surface model, the accurate expression and detail retention of the concave seam area of ​​the stele are achieved. The brush tool of the 3D modeling software is used to manually select the concave seam boundary to ensure accurate identification of the carved part on the stele. The depth difference of the concave seam boundary is analyzed and the boundary is automatically adjusted using an adaptive filtering algorithm. The adaptive filter dynamically adjusts the filtering strength according to the local characteristics of the data, effectively suppressing noise while retaining key detail information. A mask is generated based on the adjusted concave seam boundary, and the mask boundary is manually fine-tuned to ensure full coverage of the concave seam area. The depth difference of the concave seam boundary is converted into a grayscale image through a grayscale conversion algorithm. The brightness value of the pixel is adjusted, so that the deeper concave areas appear as darker areas in the grayscale image, and the shallower areas appear as brighter areas. The height differences on the surface of the stele are clearly shown in the grayscale image, which enhances the visual layering and detail recognition of the image. The contrast of the grayscale image is enhanced through histogram equalization, which significantly increases the brightness difference between deep and shallow areas and makes the details in the image more prominent. The image is smoothed through a Gaussian filter to eliminate subtle noise, ensure the quality and clarity of the grayscale image, and achieve accurate capture and expression of the concave seam information on the surface of the stele. The generated grayscale image is rich in details and has clear layers, providing high-quality basic data for the subsequent generation of digital rubbings.

[0068] S4, extracting grayscale information of the concave seam area on the surface of the stone tablet from the grayscale image, and generating a digital rubbing of the stone tablet according to the grayscale information;

[0069] Specifically, the grayscale information of the concave seam area on the surface of the stele is extracted from the grayscale image, and the digital rubbing of the stele is generated according to the grayscale information, which means that the grayscale image is converted into a binary image using PS image processing software, and the optimal threshold is automatically determined by Otsu's threshold segmentation method, and the pixels in the grayscale image are divided into black and white, the concave seam area is black, and the other areas are white. Otsu's threshold segmentation method is an automatic threshold selection method for image segmentation, which finds the optimal threshold by maximizing the inter-class variance, and divides the grayscale image into foreground and background.

[0070] The gradient of the binary image is calculated using the Canny edge detection algorithm, the concave seam boundary is detected, and the concave seam contour in the binary image is extracted as a digital rubbing. The Canny edge detection algorithm is a multi-stage edge detection algorithm used to find the edge in the image while minimizing the influence of noise. The edge line of the digital rubbing is refined using the non-maximum suppression algorithm. Non-maximum suppression is a commonly used algorithm in the field of computer vision and image processing, mainly used in edge detection and target detection, which retains meaningful strong edges or strong responses and suppresses unnecessary weak responses.

[0071] Use the repair brush tool to repair the digital rubbing;

[0072] Make global adjustments to digital rubbings, including levels, brightness, and contrast adjustments;

[0073] Perform color correction on digital rubbings according to display requirements;

[0074] The generated digital rubbings are verified using the ImageMagick image verification tool, which is used to process, edit, and convert various image formats.

[0075] The grayscale information of the concave seam area on the surface of the stele was extracted from the grayscale image, and an accurate digital rubbing was generated based on this information, achieving a fine restoration of the details of the stele surface. The grayscale image was converted into a binary image using Otsu's threshold segmentation method, and the optimal threshold was automatically determined. The pixels in the image were divided into foreground and background parts, thereby accurately separating the concave seam area. The accuracy of the segmentation was ensured by maximizing the inter-class variance, avoiding the error of artificially setting the threshold. The Canny edge detection algorithm was used to calculate the gradient of the binary image, detect the concave seam boundary, and extract the precise concave seam contour, effectively reducing the influence of noise. The edge lines were refined using the non-maximum suppression algorithm, retaining meaningful strong edges. , while suppressing unnecessary weak responses, ensuring the accuracy and clarity of the digital rubbings, using the patch brush tool to repair the digital rubbings to make up for any possible defects or errors, and making global adjustments to the digital rubbings, including adjustments to color levels, brightness, and contrast, to ensure that the overall visual effect of the image meets the display requirements, and further improves the visibility of the rubbings through color correction. The ImageMagick tool is used to verify the generated digital rubbings to ensure that their format, quality, and consistency meet the standards. It not only achieves high-precision capture and restoration of the concave seam information on the surface of the stone tablet, but also optimizes the quality of the digital rubbings through a series of image processing steps, making them more suitable for display, preservation, and further academic research.

[0076] S5. Archive and store all relevant data, and integrate the archived data files into the central data management system for cross-terminal visualization operations;

[0077] Specifically, archiving, organizing and storing all relevant data means creating a separate folder for each type of data after generating the digital rubbings, archiving all relevant data, including original three-dimensional data, three-dimensional surface models, processed grayscale images and digital rubbings using a unified naming rule, and storing the archived data files in a storage device.

[0078] By archiving, organizing and storing all relevant data, systematic management of various types of data in the process of generating digital rubbings of stone tablets is achieved. Independent folders are created for each type of data, and archived using unified naming rules, ensuring orderly organization and convenient search of data, helping to avoid data confusion or loss, while improving data traceability and consistency. Storing archived data files in storage devices provides a safe and reliable means of data preservation, ensuring long-term preservation and stable access to data, which not only facilitates subsequent data call, analysis and reuse, but also enhances the efficiency and reliability of the entire data management process, and ensures the integrity and availability of digital rubbings of stone tablets.

[0079] Furthermore, integrating the archived data files into the central data management system for cross-terminal visualization operations means integrating the archived data files into the central data management system, connecting the data files with the database of the central data management system using the RESTful API interface, assigning different access rights to users of different levels, integrating the WelGL technology, embedding the three-dimensional surface model and digital rubbings into the front-end interface of the system, and allowing users to perform cross-terminal visualization operations.

[0080] By integrating archived data files into the central data management system, efficient cross-terminal visualization operations are achieved. The data files are seamlessly connected to the system database using the RESTful API interface, ensuring real-time access and management of the data. The system provides flexible access rights allocation for users of different levels to ensure data security and confidentiality. After integrating WebGL technology, three-dimensional surface models and digital rubbings can be directly presented in the system's front-end interface. Users can perform interactive visualization operations on different terminals, greatly improving data accessibility and user experience. It also provides solid technical support for multi-platform applications and displays, ensuring the widespread application and effective management of digital results.

[0081] Example 2

[0082] This is the second embodiment of the present invention, and the difference between this embodiment and the previous embodiment is that:

[0083] If the functions are implemented in the form of 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 the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0084] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0085] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0086] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

Claims

1. A method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model, characterized in that: include, Scan the stone tablet using a three-dimensional data scanner to obtain the three-dimensional data of the stone tablet and perform data splicing to form a three-dimensional data set; Preprocess the 3D data set and construct a 3D surface model of the stele; Extract the grayscale image of the stele surface from the three-dimensional surface model; Extracting grayscale information of the concave seam area on the surface of the stone tablet from the grayscale image, and generating a digital rubbing of the stone tablet according to the grayscale information; All relevant data are archived and stored, and the archived data files are integrated into the central data management system for cross-terminal visualization operations.

2. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 1, characterized in that: Scanning the stele with a three-dimensional data scanner to obtain three-dimensional data of the stele means selecting a high-precision three-dimensional laser scanner, performing preliminary settings of the device according to scanning requirements, the preliminary settings of the device including calibration of the three-dimensional laser scanner and setting of scanning parameters, and selecting multiple scanning positions according to the size and shape of the stele; Starting the 3D laser scanner, and sequentially acquiring 3D data of each scanning position of the stone tablet according to the selected multiple scanning positions, and storing the 3D data in the internal memory of the 3D laser scanner after each scanning is completed; After all scan locations are scanned, transfer the data to the computer via Wi-Fi.

3. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 2, characterized in that: The data stitching to form a three-dimensional data set refers to aligning and stitching the three-dimensional data of multiple scanning positions for the first time using the automatic alignment function of the three-dimensional scanning software in the computer according to the built-in positioning information of the three-dimensional data scanner to form a complete three-dimensional data set.

4. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 3, characterized in that: The preprocessing of the three-dimensional data set and constructing the three-dimensional surface model of the stone tablet refers to preprocessing the three-dimensional data set, including using a Gaussian filter to perform denoising on the three-dimensional data, and using a K-means clustering method to remove abnormal data points in the three-dimensional data set; Import the preprocessed 3D data set into the 3D modeling software; Based on the geometric features of the stone tablet surface, the feature points in the 3D data set are defined. The feature points include the sharp corners, corners and edges of the carved text on the stone tablet surface. The ICP algorithm is used to perform a second alignment and splicing of all the 3D data in the 3D data set based on the defined feature points. According to the aligned and spliced ​​3D data sets, a 3D surface model is generated using the Delaunay triangulation algorithm, and the generated 3D surface model is refined, including adjusting the mesh edge length and applying the Laplacian smoothing algorithm to reduce the surface sharpness and smooth the model; Use Geomagic Design X topology analysis tools in 3D modeling software to automatically detect and repair topological defects in models; The Geomagic Control X error analysis tool is used to compare the 3D surface model with the original 3D data to generate an error distribution map. By analyzing the error distribution map, local deviations and defects in the 3D surface model are identified. Based on the identified local deviations and defects, the 3D surface model is refined again. By manually adjusting the 3D surface model, the surface of the model is pulled and pushed to fill the defects of the model.

5. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 4, characterized in that: Extracting the grayscale image of the stone tablet surface from the three-dimensional surface model refers to manually selecting the concave seam boundary of the stone tablet surface in the three-dimensional surface model by using the brush tool of the three-dimensional modeling software, the concave seam boundary including the sunken part of the inscription and the engraved line, and automatically adjusting the selected concave seam boundary by using the adaptive filtering algorithm by analyzing the depth difference between the shallowest point and the deepest point of the manually selected concave seam boundary; A mask is generated based on the self-adaptively adjusted concave seam boundary, the boundary of the mask is manually adjusted, and the grayscale value of each pixel in the mask is determined according to the depth difference of the concave seam boundary by a grayscale conversion algorithm; Generate a grayscale image based on the grayscale value of each pixel in the mask, and use the histogram equalization in the contrast enhancement algorithm to increase the difference between the dark and light areas in the grayscale image; The enhanced grayscale image is subjected to noise removal, and a Gaussian filter is used to smooth the image and eliminate subtle noise.

6. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 5, characterized in that: Extracting grayscale information of the concave seam area on the surface of the stele from the grayscale image, and generating a digital rubbing of the stele according to the grayscale information means using PS image processing software to convert the grayscale image into a binary image, automatically determining the optimal threshold by Otsu's threshold segmentation method, dividing the pixels in the grayscale image into black and white, with the concave seam area being black and the other areas being white; The Canny edge detection algorithm is used to calculate the gradient of the binary image, detect the concave seam boundary, and extract the concave seam contour in the binary image as the digital rubbing. The non-maximum suppression algorithm is used to refine the edge lines of the digital rubbing. Use the repair brush tool to repair the digital rubbing; Make global adjustments to digital rubbings, including levels, brightness, and contrast adjustments; Perform color correction on digital rubbings according to display requirements; Use ImageMagick image verification tool to verify the generated digital rubbings.

7. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 6, characterized in that: The said archiving, organizing and storing all relevant data means that after generating the digital rubbings, a separate folder is created for each type of data, all relevant data, including original three-dimensional data, three-dimensional surface models, processed grayscale images and digital rubbings are archived using a unified naming rule, and the archived data files are stored in a storage device.

8. The method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as claimed in claim 7, characterized in that: The integration of archived data files into the central data management system for cross-terminal visualization operations refers to integrating the archived data files into the central data management system, connecting the data files and the database of the central data management system using the RESTful API interface, assigning different access rights to users of different levels, integrating WelGL technology, and embedding three-dimensional surface models and digital rubbings into the front-end interface of the system, allowing users to perform cross-terminal visualization operations.

9. A computer device comprising: Memory and processor; The memory stores a computer program, characterized in that: when the processor executes the computer program, the steps of the method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as described in any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for digital rubbing of stone tablets and stone carvings based on a three-dimensional laser scanning model as described in any one of claims 1 to 8 are implemented.

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