Stone cultural relic weathering degree evaluation method and system based on high-definition photography technology

Abstract

The invention discloses a stone cultural relic weathering degree evaluation method and system based on a high-definition photography technology, and the method comprises the steps: carrying out the photographing of a stone cultural relic through employing a high-definition close-range photography technology, and obtaining a high-definition image of the stone cultural relic; determining a stone cultural relic weathering characteristic color scale; processing the high-definition image of the stone cultural relic by using an image processing technology, performing weathering partition evaluation, and calculating areas of different weathering grades in the stone cultural relic and the area ratio of the areas to the whole cultural relic; and evaluating the weathering degree current situation of the stone cultural relics. According to the method, the surface color weathering degree coefficient of the stone cultural relics is calculated from three aspects of protolith weathering degree, water seepage surface and pigment weathering by utilizing an image analysis technology, the overall weathering degree coefficient of the stone cultural relics is quantitatively calculated by adopting a structural similarity SSIM algorithm, and the weathering degree of the stone cultural relics is remarkably evaluated, so that the evaluation efficiency is remarkably improved, and the evaluation accuracy is improved. And the problem of quantitative evaluation is solved, and the weathering degree of the stone cultural relics can be visually displayed.

Description

Technical Field

[0001] The present invention relates to the technical field of weathering assessment of cultural relics, and in particular to a method and system for assessing the weathering degree of stone cultural relics based on high-definition photography technology. Background Art

[0002] Stone cultural relics, as witnesses of historical civilization, carry rich historical information and artistic value, and are non-renewable cultural heritage. However, due to the erosion of the natural environment, climate change, and interference from human factors, these cultural relics are facing serious weathering damage. Weathering not only affects the beauty of cultural relics, but may also lead to a decrease in structural stability and even threaten the integrity and safety of cultural relics. Therefore, effective weathering assessment of stone cultural relics is crucial for formulating scientific protection and restoration plans.

[0003] At present, the weathering assessment of stone cultural relics mainly relies on traditional detection methods, such as infrared spectroscopy, X-ray diffraction, ultrasonic flaw detection and other technologies. Although these methods can provide certain weathering information, they are often complicated to operate, costly, and difficult to achieve a rapid and comprehensive assessment of the degree of weathering of cultural relics. In addition, some methods may require contact with cultural relics, which poses a risk of damaging them. With the development of technology, high-definition photography and image analysis technology have begun to be applied in the field of cultural relic protection, but most studies still focus on the measurement of the morphological characteristics of cultural relics and have not yet been widely used in the assessment of the degree of weathering.

[0004] Existing technologies have obvious deficiencies in the assessment of weathering of stone cultural relics. First, traditional detection methods usually require professional equipment and technicians, which limits the popularity and efficiency of the assessment. Secondly, these methods can often only provide local or specific weathering information, and lack a comprehensive assessment of the overall weathering condition of cultural relics. In addition, the high cost and potential risk of damage also limit the application of these methods in large-scale cultural relic protection projects. Therefore, the development of a low-cost, high-efficiency, non-contact method for assessing the degree of weathering of stone cultural relics is of great significance to improving the quality and efficiency of cultural relic protection work. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the purpose of the present invention is to provide a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology. The method uses high-definition close-range photogrammetry technology to photograph stone cultural relics to obtain high-definition images of the stone cultural relics; uses image processing technology and according to the weathering characteristic color scale of the stone cultural relics to evaluate the three aspects of original rock weathering degree, seepage surface and pigment weathering of the stone cultural relics, thereby solving the problem of quantitative evaluation; then uses a computer program to calculate the area of ​​different weathering grades in the stone cultural relics and the area ratio of the entire cultural relics; and based on the area of ​​different weathering grades and the area ratio of the entire cultural relics, quickly evaluate the current status of the weathering degree of the stone cultural relics, and determine prevention and repair plans.

[0006] According to a first aspect of the present invention, a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology is provided, comprising:

[0007] S100, photographing the stone cultural relic using high-definition close-up photography technology to obtain a high-definition image of the stone cultural relic;

[0008] S200, collecting original rock samples near the stone cultural relics, and determining the color scale of the weathering characteristics of the stone cultural relics;

[0009] S300, using image processing technology to perform color and contrast correction on the high-definition image of the stone cultural relic, analyzing the color of each pixel, and evaluating the weathering zoning of the stone cultural relic according to the weathering characteristic color scale of the stone cultural relic, and calculating the area of ​​different weathering grades in the stone cultural relic and the area ratio of the entire cultural relic;

[0010] S400, filling the corresponding unweathered colors at different positions into the corresponding high-definition photos, and substituting the photos before and after coloring into the structural similarity SSIM algorithm to calculate the similarity between the current high-definition photos of the stone cultural relics and the unweathered high-definition photos, and using this to evaluate the weathering degree of the stone cultural relics;

[0011] S500: Determine a prevention and restoration plan based on the areas of different weathering grades and the current weathering degree of the stone cultural relics.

[0012] Furthermore, the color scale of the weathering characteristics of stone cultural relics includes a color scale of the weathering degree of the original rock, a color scale of the moisture content of the original rock, and a color scale of the pigment of the colored surface of the original rock.

[0013] Furthermore, the method for determining the color scale of the original rock weathering degree or moisture content includes: collecting original rock samples of different weathering grades or moisture contents, making them into cylindrical samples, fixing the cylindrical samples of different weathering grades or moisture contents on the rock sample mounts respectively, turning on a shadowless lamp, using a high-definition camera to photograph the cylindrical samples, inputting the images into a computer program for image processing, extracting the color information of the samples, and establishing a color scale of the original rock weathering degree or moisture content of stone cultural relics.

[0014] Furthermore, the method for determining the color scale of the colored surface of the stone cultural relic includes: determining the color of the pigment under different weathering degrees according to the mineral composition of the pigment on the surface of the stone cultural relic, and establishing the color scale of the colored surface of the stone cultural relic.

[0015] Furthermore, the step S300 includes:

[0016] S301, converting the high-definition image from the RGB color space to the CIELAB color space for color correction, the conversion formula is:

[0017]

[0018] In the formula, X, Y, and Z are the color channel values ​​of a pixel in the image in the color space before conversion; L* represents brightness, ranging from 0 to 100; a* represents the color range from green to red, with positive values ​​indicating the red direction and negative values ​​indicating the green direction; b* represents the color range from blue to yellow, with positive values ​​indicating the yellow direction and negative values ​​indicating the blue direction;

[0019] S302, extracting color features from each pixel, reducing the data dimension using dimensionality reduction technology, and training using a supervised learning algorithm, classifying each pixel based on the trained model and assigning it to different weathering levels;

[0020] S303: Count the number of pixels in each classification area and calculate the actual area according to the image resolution.

[0021] Furthermore, the step S400 includes:

[0022] S401, evaluate the similarity in brightness of two images x and y by comparing their average brightness:

[0023]

[0024] Where l(x,y) represents the brightness similarity; μ x and μ y are the average brightness of images x and y respectively; C1 is a constant used to avoid the denominator being zero, usually taken as (K1L) 2, where K1 is a small constant and L is the dynamic range of the image grayscale;

[0025] S402, evaluating the similarity in contrast between the two images x and y by comparing their standard deviations:

[0026]

[0027] Where c(x,y) represents the contrast similarity; σ x and σ y are the standard deviations of images x and y respectively; C1 is a constant, usually taken as (K2L) 2 , where K1 is a very small constant (such as 0.03) and L is the dynamic range of the image grayscale.

[0028] S403, evaluating the structural similarity of the two images x and y by comparing their mutual correlation coefficients: the structural similarity is measured as follows:

[0029]

[0030] Where s(x,y) represents the structural similarity; σ xy Represents the covariance of images x and y.

[0031] Furthermore, the step S400 includes: combining the similarities of the three dimensions into an overall similarity index according to the SSIM algorithm:

[0032] SSIM(x,y)=[l(x,y)]α·[c(x,y)] β ·[s(x,y)]γ

[0033] Where SSIM(x, y) represents the overall similarity; α, β, and γ are parameters used to adjust the correlation between the three factors.

[0034] According to a second aspect of the present invention, a system for evaluating the weathering degree of stone cultural relics based on high-definition photogrammetry technology is provided, which is implemented by applying any step of the above-mentioned method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology, including:

[0035] The first module is used to photograph the stone cultural relics using high-definition close-up photography technology to obtain high-definition images of the stone cultural relics;

[0036] The second module is used to collect the original rock samples near the stone cultural relics and determine the color scale of the weathering characteristics of the stone cultural relics;

[0037] The third module is used to perform color and contrast correction on the high-definition image of the stone cultural relic using image processing technology, analyze the color of each pixel, evaluate the weathering zoning of the stone cultural relic according to the weathering characteristic color scale of the stone cultural relic, and calculate the area of ​​different weathering levels in the stone cultural relic and the area ratio of the entire cultural relic;

[0038] The fourth module is used to fill the corresponding unweathered colors at different positions into the corresponding high-definition photos, and substitute the photos before and after coloring into the structural similarity SSIM algorithm to calculate the similarity between the current high-definition photos of stone cultural relics and the unweathered high-definition photos, and use this to evaluate the weathering degree of stone cultural relics;

[0039] The fifth module is used to determine the prevention and restoration plan based on the areas of different weathering levels and the current weathering degree of the stone cultural relics.

[0040] According to a third aspect of the present invention, a device for determining a color scale for weathering characteristics of stone cultural relics is provided, which is applied to any step of the above-mentioned method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology, comprising:

[0041] A base, comprising a standard color band arranged on one side of the base and a rock sample holder arranged on the other side, wherein the original rock sample is fixed on the rock sample holder;

[0042] A high-definition camera unit is disposed above the base, the high-definition camera unit is fixed with a tripod, and the lens is directed downward toward the original rock sample, so as to capture a high-resolution image of the original rock sample; and

[0043] The shadowless lamp arranged on one side of the high-definition camera unit is used to provide uniform and shadow-free lighting to ensure the accuracy of image color.

[0044] Beneficial effects of the present invention:

[0045] 1. The present invention provides a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology. The method uses high-definition close-range photogrammetry technology to shoot stone cultural relics to obtain high-definition images of the stone cultural relics; uses image processing technology and a color scale of weathering characteristics of the stone cultural relics to evaluate the weathering degree of the original rock, the seepage surface and the weathering of the pigment of the stone cultural relics; then uses a computer program to calculate the area of ​​different weathering grades in the stone cultural relics and the area ratio of the entire cultural relics; and according to the area of ​​different weathering grades and the area ratio of the entire cultural relics, the current status of the weathering degree of the stone cultural relics is quickly evaluated, and prevention and repair plans are determined. This method not only significantly improves the evaluation efficiency, but also solves the problem of quantitative evaluation, and can intuitively display the weathering degree of the stone cultural relics, so that non-professionals can also easily understand the evaluation results, which is helpful to improve the public participation in cultural relic protection.

[0046] 2. The weathering characteristic color scale determination device proposed in the present invention is simple and practical, and only requires components such as a high-definition camera, a shadowless lamp, and a special rock sample fixing plate, without other expensive monitoring equipment, low cost, and a simple determination process.

[0047] 3. The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology proposed in the present invention will not cause damage to the cultural relics, and uses different scales for evaluation according to different rock types and environmental factors. Compared with the traditional method of using a consistent rock weathering grade to evaluate stone cultural relics, it can more accurately reflect the weathering status of stone cultural relics.

[0048] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0050] Figure 1 This is a flow chart of a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology in an embodiment of the present invention;

[0051] Figure 2 It is a schematic diagram of a device for determining a color scale of weathering characteristics of stone cultural relics in an embodiment of the present invention;

[0052] Figure 3 It is a schematic diagram of a base of a device for determining a color scale of weathering characteristics of stone cultural relics in an embodiment of the present invention;

[0053] In all the drawings, the same reference numerals represent the same technical features, specifically: 1-base, 11-standard color card, 12-rock sample mount, 13-rock sample, 2-high-definition camera unit, 3-shadowless lamp. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0055] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0057] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as in the embodiments of this application.

[0058] High-definition close-range photogrammetry is an advanced non-contact measurement method that uses high-resolution photographic equipment and advanced image processing technology to perform high-precision measurements on close-range target objects to obtain their geometric size, shape, texture, and three-dimensional spatial information. This technology uses high-precision photographic equipment to capture images of target objects, and then uses image processing technology to extract geometric information from the image, ultimately achieving accurate measurement of the target object. Compared with traditional contact measurement methods, high-definition close-range photogrammetry has the advantages of non-contact, high efficiency, and high precision. Currently, in the field of cultural relics restoration, high-definition photogrammetry is mainly used to measure the geometric size and morphological characteristics of cultural relics, but it has not yet been used to assess the degree of weathering of stone cultural relics.

[0059] Stone cultural relics are affected by many weathering processes, and their physical and mechanical properties, material composition and other aspects have undergone significant changes, which will eventually be reflected in the apparent characteristics of stone cultural relics, especially the color characteristics. These factors include the weathering degree of the rock itself, the water content, the discontinuity surface and the weathering degree of the cultural relic coloring layer. At the same time, it is also necessary to eliminate the influence of color changes caused by environmental factors such as the strength of the light source. Therefore, it is necessary to determine the color scale for different weathering conditions and weathering degrees, so as to judge the weathering state of stone cultural relics by comparing the color scale, evaluate the current status of weathering, and track and monitor the weathering traces accordingly, so as to provide a basis for the further protection and restoration of stone cultural relics.

[0060] The invention provides a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology. The method uses high-definition close-range photogrammetry technology to shoot stone cultural relics to obtain high-definition images of the stone cultural relics; uses image processing technology and a color scale of weathering characteristics of the stone cultural relics to evaluate the weathering degree of the original rock, the seepage surface and the weathering of the pigment of the stone cultural relics, thereby solving the problem of quantitative evaluation; then uses a computer program to calculate the areas of different weathering grades in the stone cultural relics and the area ratios of the entire cultural relics; and according to the areas of different weathering grades and the area ratios of the entire cultural relics, the current status of the weathering degree of the stone cultural relics can be quickly evaluated, and prevention and repair plans can be determined.

[0061] Embodiment 1:

[0062] like Figure 1 As shown, the embodiment of the present invention provides a method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology, comprising:

[0063] S100, photographing the stone cultural relic using high-definition close-up photography technology to obtain a high-definition image of the stone cultural relic; the high-definition image of the stone cultural relic also includes a standard color card

[0064] S200, collecting original rock samples near the stone cultural relics, and determining the color scale of the weathering characteristics of the stone cultural relics; the color scale of the weathering characteristics of the stone cultural relics includes the color scale of the original rock weathering degree, the color scale of the original rock moisture content, and the color scale of the original rock coloring surface pigment;

[0065] Specifically, the method for determining the color scale of the weathering degree of the original rock of stone cultural relics includes:

[0066] Original rock samples of different weathering levels near stone cultural relics were collected and made into cylindrical samples with a height of 5 mm and a diameter of 20 mm indoors. The cylindrical rock samples of different weathering levels (unweathered, slightly weathered, moderately weathered, strongly weathered, and fully weathered) were fixed on the rock sample bayonet on the base, the shadowless lamp was turned on, and a high-definition camera was used to take pictures. The obtained images were input into a computer program for processing, and the color scale of the weathering degree of the original rock of the stone cultural relic was obtained as shown in Table 1 (the weathering degree of the original rock surface is different, and the color characteristics presented are also different. The original rock sample selected in this embodiment is red sandstone):

[0067] Table 1

[0068]

[0069] The method for determining the color scale of the moisture content of the original rock of stone cultural relics includes: collecting original rock samples near the stone cultural relics, and making cylindrical samples with a height of 5mm and a diameter of 20mm indoors. The rock samples with different moisture contents (taking red sandstone as an example, divided into: 0.5%, 1.0%, 1.5%, 2.0%, 2.5%) are fixed on the rock sample clamp above the base, the shadowless lamp is turned on, and a high-definition camera is used to take pictures, and the obtained images are input into a computer program for processing, and the color scale of the moisture content of the original rock of the stone cultural relics is obtained as shown in Table 2 (the moisture content of the original rock surface is different, and the color characteristics presented are also different. The original rock sample selected in this embodiment is red sandstone):

[0070] Table 2

[0071]

[0072] The method for determining the color scale of the colored surface of a stone cultural relic comprises: determining the color of the pigment at different weathering degrees according to the mineral composition of the pigment on the surface of the stone cultural relic, and obtaining the color scale of the colored surface of the stone cultural relic as shown in Table 3 (the color characteristics presented are different due to the different weathering degrees of the color pigment on the surface of the original rock. In this embodiment, the color pigment selected on the surface of the original rock is a red iron-containing pigment):

[0073] Table 3

[0074]

[0075] S300, using image processing technology to perform color and contrast correction on the high-definition image of the stone cultural relic, analyzing the color of each pixel, and evaluating the weathering zoning of the stone cultural relic according to the weathering characteristic color scale of the stone cultural relic, and calculating the area of ​​different weathering grades in the stone cultural relic and the area ratio of the entire cultural relic;

[0076] Specific:

[0077] S301, converting the high-definition image from the RGB color space to the CIELAB color space for color correction, the conversion formula is:

[0078]

[0079] In the formula, X, Y, and Z are the color channel values ​​of a pixel in the image in the color space before conversion; L* represents brightness, ranging from 0 to 100; a* represents the color range from green to red, with positive values ​​indicating the red direction and negative values ​​indicating the green direction; b* represents the color range from blue to yellow, with positive values ​​indicating the yellow direction and negative values ​​indicating the blue direction;

[0080] S302, extracting color features from each pixel, reducing the data dimension using dimensionality reduction technology, and training using a supervised learning algorithm, classifying each pixel based on the trained model and assigning it to different weathering levels;

[0081] S303: Count the number of pixels in each classification area and calculate the actual area according to the image resolution.

[0082] S400, filling the corresponding unweathered colors at different positions into the corresponding high-definition photos, and substituting the photos before and after coloring into the structural similarity SSIM algorithm to calculate the similarity between the current high-definition photos of the stone cultural relics and the unweathered high-definition photos, and using this to evaluate the weathering degree of the stone cultural relics;

[0083] Specifically: S401, evaluate the similarity in brightness of two images x and y by comparing their average brightness:

[0084]

[0085] Where l(x,y) represents the brightness similarity; μ x and μ y are the average brightness of images x and y respectively; C1 is a constant used to avoid the denominator being zero, usually taken as (K1L) 2 , where K1 is a very small constant (such as 0.01), and L is the dynamic range of the image grayscale;

[0086] S402, evaluating the similarity in contrast between the two images x and y by comparing their standard deviations:

[0087]

[0088] Where c(x,y) represents the contrast similarity; σ x and σ y are the standard deviations of images x and y respectively; C1 is a constant, usually taken as (K2L) 2, where K1 is a very small constant (such as 0.03) and L is the dynamic range of the image grayscale.

[0089] S403, evaluating the structural similarity of the two images x and y by comparing their mutual correlation coefficients: the structural similarity is measured as follows:

[0090]

[0091] Where s(x,y) represents the structural similarity; σ xy Represents the covariance of images x and y.

[0092] S500: Evaluate the current weathering level of the stone cultural relics based on the areas of different weathering levels and the current weathering level of the stone cultural relics, and determine prevention, control and restoration plans.

[0093] In summary, the method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology provided by the present invention uses high-definition close-range photogrammetry technology to shoot stone cultural relics to obtain high-definition images of the stone cultural relics; uses image processing technology and according to the stone cultural relic weathering characteristic color scale to evaluate the stone cultural relics in three aspects: original rock weathering degree, seepage surface and pigment weathering; finally, by using a computer program to calculate the area of ​​different weathering grades in the stone cultural relics and the area ratio of the entire cultural relics, and according to the area of ​​different weathering grades and the area ratio of the entire cultural relics, the current weathering degree of the stone cultural relics can be quickly evaluated, and prevention and repair plans can be determined, which effectively solves the problem that cultural relics are difficult to quantitatively evaluate, can intuitively display the weathering degree of stone cultural relics, so that non-professionals can also easily understand the evaluation results, which is helpful to improve the public participation in cultural relic protection work, and the method will not cause damage to the cultural relics, and can use different scales for evaluation according to different rock types and environmental factors. Compared with the traditional method of using a consistent rock weathering grade to evaluate stone cultural relics, it can more accurately reflect the weathering status of stone cultural relics.

[0094] Embodiment 2:

[0095] like Figure 2 Figure 3As shown, an embodiment of the present invention provides a device for determining a color scale of weathering characteristics of stone cultural relics, comprising: a base 1, comprising a standard color ribbon 11 arranged on one side of the base 1 and a rock sample mount 12 arranged on the other side, wherein an original rock sample 13 is fixed on the rock sample mount 12; a high-definition camera unit 2 arranged above the base 1, wherein the high-definition camera unit 2 is fixed with a tripod, and a lens is aimed downward at the original rock sample 13, so as to capture a high-resolution image of the original rock sample 13; and a shadowless lamp 3 arranged on one side of the high-definition camera unit 2, so as to provide uniform and shadow-free lighting to ensure the accuracy of the image color; the design of the device for determining a color scale of weathering characteristics of stone cultural relics provided in this embodiment takes into account the user's operating convenience, and through the modular design of the high-definition camera unit, the shadowless lamp, the sample fixing device, etc., the entire evaluation process is simple and easy, and does not require complicated equipment operation skills, so it is convenient for cultural relics protection workers with different backgrounds to use.

[0096] The method for determining the color scale of the original rock weathering degree using the above-mentioned device includes: collecting original rock samples 13 of different weathering grades, fixing the original rock samples 13 of different weathering grades on the rock sample mount 12 respectively, turning on the shadowless lamp 3, using the high-definition camera unit 2 to shoot the original rock sample 13, obtaining the high-resolution image of the original rock sample 13 and inputting it into a computer program for image processing, extracting color information and establishing a color scale of the original rock weathering degree of the stone cultural relic; the method for determining the color scale of the original rock moisture content using the above-mentioned device includes: the method for determining the color scale of the original rock moisture content of the stone cultural relic includes: collecting original rock samples 13 of different moisture contents, fixing the original rock samples 13 of different moisture contents on the rock sample mount 12 respectively, turning on the shadowless lamp 3, using the high-definition camera unit 2 to shoot the original rock sample 13, obtaining the high-resolution image of the original rock sample 13 and inputting it into a computer program for image processing, extracting color information and establishing a color scale of the original rock moisture content of the stone cultural relic.

[0097] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0098] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology, characterized in that: include: S100, photographing the stone cultural relic using high-definition close-up photography technology to obtain a high-definition image of the stone cultural relic; S200, collecting original rock samples near the stone cultural relics, and determining the color scale of the weathering characteristics of the stone cultural relics; S300, using image processing technology to perform color and contrast correction on the high-definition image of the stone cultural relic, analyzing the color of each pixel, and evaluating the weathering zoning of the stone cultural relic according to the weathering characteristic color scale of the stone cultural relic, and calculating the area of ​​different weathering grades in the stone cultural relic and the area ratio of the entire cultural relic; S400, filling the corresponding unweathered colors at different positions into the corresponding high-definition photos, and substituting the photos before and after coloring into the structural similarity SSIM algorithm to calculate the similarity between the current high-definition photos of the stone cultural relics and the unweathered high-definition photos, and using this as the evaluation of the weathering degree of the stone cultural relics; S500: Determine a prevention and restoration plan based on the areas of different weathering grades and the current weathering degree of the stone cultural relics.

2. The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to claim 1 is characterized in that: The color scale of the weathering characteristics of stone cultural relics includes a color scale of the weathering degree of the original rock, a color scale of the moisture content of the original rock, and a color scale of the pigment of the colored surface of the original rock.

3. The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to claim 2 is characterized in that: The method for determining the color scale of the original rock weathering degree or moisture content includes: collecting original rock samples with different weathering grades or moisture contents, making them into cylindrical samples, fixing the cylindrical samples with different weathering grades or moisture contents on rock sample mounts respectively, turning on a shadowless lamp, using a high-definition camera to photograph the cylindrical samples, inputting the images into a computer program for image processing, extracting the color information of the samples, and establishing a color scale of the original rock weathering degree or moisture content of stone cultural relics.

4. The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to claim 2 is characterized in that: The method for determining the color scale of the colored surface of the stone cultural relic comprises: determining the color of the pigment under different weathering degrees according to the mineral composition of the pigment on the surface of the stone cultural relic, and establishing the color scale of the colored surface of the stone cultural relic.

5. According to the method for evaluating the weathering degree of stone cultural relics based on high-definition photogrammetry technology as described in claim 2, it is characterized in that: Different sample colors in the stone cultural relic weathering characteristic color scale have corresponding RGB values ​​and weathering characteristic values.

6. A method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to any one of claims 1 to 5, characterized in that: The step S300 includes: S301, converting the high-definition image from the RGB color space to the CIELAB color space for color correction, the conversion formula is: Where X, Y, and Z are the values ​​of the color channel value of a pixel in the image in the color space before conversion; L* represents brightness, ranging from 0 to 100; a* represents the color range from green to red, with positive values ​​indicating the red direction and negative values ​​indicating the green direction; b* represents the color range from blue to yellow, with positive values ​​indicating the yellow direction and negative values ​​indicating the blue direction; S302, extracting color features from each pixel, reducing the data dimension using dimensionality reduction technology, and training using a supervised learning algorithm, classifying each pixel based on the trained model and assigning it to different weathering levels; S303: Count the number of pixels in each classification area and calculate the actual area according to the image resolution.

7. A method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to any one of claims 1 to 5, characterized in that: The step S400 includes: S401, evaluate the similarity in brightness of two images x and y by comparing their average brightness: Where l(x,y) represents the brightness similarity; μ x and μ y are the average brightness of images x and y respectively; C1 is a constant used to avoid the denominator being zero, usually taken as (K1L) 2 , where K1 is a very small constant (such as 0.01), and L is the dynamic range of the image grayscale; S402, evaluating the similarity in contrast between the two images x and y by comparing their standard deviations: Where c(x,y) represents the contrast similarity; σ x and σ y are the standard deviations of images x and y respectively; C1 is a constant, usually taken as (K2L) 2 , where K1 is a very small constant, and L represents the dynamic range of the image grayscale; S403, evaluating the structural similarity of the two images x and y by comparing their mutual correlation coefficients: the structural similarity is measured as follows: Where s(x,y) represents the structural similarity; σ xy Represents the covariance of images x and y.

8. The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to claim 7, characterized in that: The step S400 includes: combining the similarities of the three dimensions into an overall similarity index according to the SSIM algorithm: SSIM(x,y)=[l(x,y)] α ·[c(x,y)] β ·[s(x,y)] γ Where SSIM(x, y) represents the overall similarity; α, β, and γ are parameters used to adjust the correlation between the three factors.

9. A stone cultural relic weathering degree assessment system based on high-definition photogrammetry technology, characterized in that: The method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology according to any one of claims 1 to 8 is implemented, comprising: The first module is used to photograph the stone cultural relics using high-definition close-up photography technology to obtain high-definition images of the stone cultural relics; The second module is used to collect the original rock samples near the stone cultural relics and determine the color scale of the weathering characteristics of the stone cultural relics; The third module is used to perform color and contrast correction on the high-definition image of the stone cultural relic using image processing technology, analyze the color of each pixel, evaluate the weathering zoning of the stone cultural relic according to the weathering characteristic color scale of the stone cultural relic, and calculate the area of ​​different weathering levels in the stone cultural relic and the area ratio of the entire cultural relic; The fourth module is used to fill the corresponding unweathered colors at different positions into the corresponding high-definition photos, and substitute the photos before and after coloring into the structural similarity SSIM algorithm to calculate the similarity between the current high-definition photos of stone cultural relics and the unweathered high-definition photos, and use this to evaluate the weathering degree of stone cultural relics; The fifth module is used to determine the prevention and restoration plan based on the areas of different weathering levels and the current weathering degree of the stone cultural relics.

10. A device for determining a color scale of weathering characteristics of stone cultural relics, applied to the method for evaluating the weathering degree of stone cultural relics based on high-definition photography technology as claimed in any one of claims 1 to 8, characterized in that: include: A base (1) comprises a standard color band (11) arranged on one side of the base (1) and a rock sample holder (12) arranged on the other side, wherein an original rock sample (13) is fixed on the rock sample holder (12); A high-definition camera unit (2) is arranged above the base (1), wherein the high-definition camera unit (2) is fixed by a tripod, and a lens is directed downward toward the original rock sample (13), so as to capture a high-resolution image of the original rock sample (13); as well as The shadowless lamp (3) arranged on one side of the high-definition camera unit (2) is used to provide uniform and shadow-free lighting to ensure the accuracy of image color.

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