A method and system for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning
By acquiring multi-period flooded images and water level data of pioneer vegetation in coastal salt marshes using tidal scanning technology, and reconstructing a three-dimensional morphological model using computer vision models, the accuracy and efficiency issues of measuring pioneer vegetation in coastal wetlands are solved, making it suitable for ecosystem protection and assessment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HOHAI UNIV
- Filing Date
- 2026-01-15
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies are insufficient for efficiently and accurately measuring the vertical structure and morphology of pioneer vegetation in coastal wetlands, especially parameters such as plant height, crown width, density, and biomass. Traditional methods are inefficient and prone to interfering with the environment, while satellite remote sensing and UAV mapping lack sufficient accuracy.
A tidal scanning-based method was adopted to acquire flooded images and water level data of pioneer vegetation at multiple time periods. The vegetation edge contours were extracted using computer vision models and threshold segmentation techniques. Combined with water level data, three-dimensional reconstruction was performed to generate a three-dimensional morphological model of pioneer vegetation and calculate its height, volume and biomass.
It enables accurate measurement of pioneer vegetation morphology, improves measurement precision and efficiency, and is applicable to the environmental protection and stability assessment of ecosystems.
Smart Images
Figure CN122156949A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method and system for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, belonging to the field of remote sensing measurement technology for intertidal pioneer vegetation morphology. Background Technology
[0002] The morphological characteristics of pioneer plants in coastal wetlands are crucial indicators of the structural and functional health of ecosystems, making their precise measurement essential. As early markers of coastal wetland evolution, the morphological parameters of pioneer plants, such as plant height, crown width, density, and biomass, directly reflect the success of vegetation colonization, population expansion potential, and the rate and stability of ecological geomorphological processes like siltation and erosion. These morphological data provide a scientific basis for assessing wetland carbon sequestration capacity, habitat quality, monitoring coastline resistance to erosion, and providing early warnings of ecological degradation risks. Therefore, measuring plant morphological parameters has become fundamental and urgent for a deeper understanding of the evolutionary mechanisms of coastal wetland systems and for implementing precise ecological management and restoration.
[0003] Currently, the measurement of coastal wetland plant morphology mainly relies on field measurements and remote sensing mapping techniques. Traditional manual methods, such as quadrat statistics, altimeters, and total stations, while offering high measurement accuracy, are inefficient, have limited operational range, and are prone to disturbing the fragile wetland environment. Satellite remote sensing and UAV mapping technologies are more suitable for quantifying planar parameters such as vegetation area over larger areas, but their horizontal and vertical accuracy is insufficient to meet the needs of measuring parameters such as vegetation height in pioneer plant areas. Therefore, existing technologies are significantly inadequate in identifying and measuring the vertical structure of pioneer vegetation in coastal wetlands, making it difficult to accurately extract the rapidly changing morphologies of pioneer plants.
[0004] In summary, existing measurement methods have significant limitations in terms of efficiency, scope, and cost, and there is an urgent need to develop an accurate pioneer vegetation morphology measurement scheme. Summary of the Invention
[0005] Objective: In view of at least one of the above technical problems, this application provides a method and system for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning. By extracting the outline of pioneer plants submerged by tidal rise and fall and acquiring images at multiple time periods, it provides a feasible alternative path for the distribution and construction of pioneer plant morphology and has good application prospects.
[0006] The technical solution adopted in this application is: Firstly, this application provides a method for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, including: S1. Acquire multiple consecutive images of flooded pioneer vegetation in the target intertidal zone and corresponding water level data; wherein the flooded pioneer vegetation images are acquired by imaging equipment deployed in the target intertidal zone; and the water level data are acquired using tidal level stations or by deploying water level gauges. S2. Extract the edge contour of the pioneer vegetation in the flooded image of the pioneer vegetation using a computer vision model or threshold segmentation image technology. S3. Based on the water level data corresponding to the flooded image of the pioneer vegetation, the edge contours of the pioneer vegetation are stitched together to obtain the three-dimensional edge contours of the pioneer vegetation. S4. Extract elevation point cloud data based on the three-dimensional edge contour of the pioneer vegetation, and reconstruct the three-dimensional model of the pioneer vegetation morphology based on the elevation point cloud data. S5. Based on the three-dimensional model of the pioneer vegetation morphology, calculate the measurement results of the pioneer vegetation morphology; wherein the measurement results of the pioneer vegetation morphology include the height, volume and biomass of the pioneer vegetation.
[0007] In some embodiments, step S1 includes: The shooting time interval is determined based on the tidal size and tidal level characteristics and the required vertical resolution. The pioneer vegetation in the intertidal zone is continuously photographed from at least one angle according to the time interval, multiple images containing the pioneer vegetation are obtained, and the water level data at the corresponding shooting time is marked. Based on multiple images containing pioneer vegetation and corresponding water level data, the first water level corresponding to when the pioneer vegetation begins to be submerged and the second water level corresponding to when the pioneer vegetation is completely submerged are determined. Images containing pioneer vegetation located between the first and second water levels are selected as pioneer vegetation flooded images.
[0008] In some embodiments, the imaging equipment is arranged differently depending on the actual measurement range; if the range is large, a drone is used, and if the range is small, a camera is used.
[0009] In some embodiments, the shooting angle of the image containing pioneer vegetation includes at least the shooting device being located at the center of the target intertidal zone and shooting from above, and the image containing pioneer vegetation includes the pioneer vegetation and the surrounding water.
[0010] In some embodiments, step S2, extracting the edge contours of the pioneer vegetation in the flooded image of the pioneer vegetation using a computer vision model or threshold segmentation image technology, includes: Multi-level image features are obtained by using computer vision models or threshold segmentation image technology to extract multi-level features from the flooded image of the pioneer vegetation. The initial edge contour of pioneer vegetation is obtained based on multi-level image features; The initial edge contour is refined by using an optimization module that combines vegetation texture features with spatial continuity to obtain the edge contour of pioneer vegetation.
[0011] In some embodiments, S3, based on the water level data corresponding to the flooded image of the pioneer vegetation, stitching together the edge contours of the pioneer vegetation to obtain the three-dimensional edge contour of the pioneer vegetation, includes: The edge contours of the pioneer vegetation in flooded images from different angles are associated with the corresponding water level data, and the coordinates are extracted and transformed to the same three-dimensional spatial coordinate system to obtain the three-dimensional point cloud data of the edge contours of the pioneer vegetation under the corresponding water level. The 3D point cloud data of the pioneer vegetation edge contour under different water levels are stitched and fused to obtain the 3D edge contour of the pioneer vegetation.
[0012] Furthermore, step S3 also includes: After obtaining the three-dimensional edge contour of the pioneer vegetation, the three-dimensional edge contour of the pioneer vegetation is checked, and isolated and overlapping contours with high redundancy or conflict with the overall topology are deleted to generate a continuous, complete and conflict-free three-dimensional distribution boundary of the pioneer vegetation as the final three-dimensional edge contour of the pioneer vegetation.
[0013] Secondly, this application provides a device for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, including a processor and a storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the method described in accordance with the first aspect.
[0014] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.
[0015] Fourthly, this application provides a computer device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect.
[0016] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.
[0017] Beneficial Effects: The method and system for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning provided in this application have the following advantages: This application acquires multiple consecutive flooded images of pioneer vegetation in the target intertidal zone and the corresponding water level data, extracts the edge contours of pioneer vegetation from the flooded images, and combines the water level data to stitch together the edge contours of the pioneer vegetation to obtain a three-dimensional edge contour. Based on the elevation point cloud data of the three-dimensional edge contour, a three-dimensional morphological model of the pioneer vegetation is reconstructed, thereby calculating the measurement results of the pioneer vegetation morphology. This application achieves accurate measurement of pioneer vegetation morphology under the condition that it is difficult to measure the morphology of pioneer vegetation in coastal salt marshes, improves the measurement accuracy of pioneer vegetation morphology, and is suitable for environmental protection and ecological stability assessment of coastal wetland ecosystems. Attached Figure Description
[0018] Figure 1 This is a flowchart illustrating a method for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, according to an embodiment of this application. Figure 2 This is a side view schematic diagram of the measurement of pioneer vegetation morphology in coastal salt marshes according to an embodiment of this application; Figure 3 This is a top view schematic diagram of the measurement of pioneer vegetation morphology in a coastal salt marsh according to an embodiment of this application; Figure 4 This is a schematic diagram illustrating the extraction of the outline of pioneer vegetation in coastal salt marshes according to an embodiment of this application; Figure 5 This is a schematic diagram of a three-dimensional model of the pioneer vegetation morphology of coastal salt marshes according to an embodiment of this application. Detailed Implementation
[0019] The present application will be further described below with reference to the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and should not be used to limit the scope of protection of the present application.
[0020] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0021] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0022] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0023] Example 1: This example provides a method for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, such as... Figure 1 As shown, it includes: S1. Acquire multiple consecutive images of flooded pioneer vegetation in the target intertidal zone and the corresponding water level data.
[0024] It should be noted that the sampling time interval between the consecutive images of flooded pioneer vegetation is determined based on the tidal magnitude, tidal level characteristics, and required vertical resolution. The flooded pioneer vegetation images are acquired using imaging equipment deployed in the target intertidal zone. The type of imaging equipment varies depending on the actual measurement range; a drone is used for a large range, while a camera is used for a smaller range. Water level data is acquired using tidal level stations or deployed water level gauges. The observed water level data is correlated and calibrated with the flooded pioneer vegetation images based on the sampling time.
[0025] In some embodiments, step S1 specifically includes: The shooting time interval is determined based on the tidal size and tidal level characteristics and the required vertical resolution. The pioneer vegetation in the intertidal zone is continuously photographed from at least one angle according to the time interval, multiple images containing the pioneer vegetation are obtained, and the water level data at the corresponding shooting time is marked. Based on multiple images containing pioneer vegetation and corresponding water level data, the first water level corresponding to when the pioneer vegetation begins to be submerged and the second water level corresponding to when the pioneer vegetation is completely submerged are determined. Images containing pioneer vegetation located between the first and second water levels are selected as pioneer vegetation flooded images.
[0026] It should be noted that the shooting angle of the image containing pioneer vegetation includes at least the shooting device being located at the center of the target intertidal zone and shooting from above (thus the resulting image of the flooded pioneer vegetation is almost parallel to the horizontal plane), and the image containing pioneer vegetation includes the pioneer vegetation and the surrounding water.
[0027] S2. Extract the edge contour of the pioneer vegetation in the flooded image of the pioneer vegetation using computer vision models or threshold segmentation image technology.
[0028] It should be noted that, in this embodiment, the edge contour of the pioneer vegetation is represented as the boundary line between the pioneer vegetation at the water surface and the surrounding water body.
[0029] In some embodiments, step S2 includes: Multi-level image features are obtained by using computer vision models or threshold segmentation image technology to extract multi-level features from the flooded image of the pioneer vegetation. The initial edge contour of pioneer vegetation is obtained based on multi-level image features; The initial edge contour is refined by using an optimization module that combines vegetation texture features with spatial continuity to obtain an accurate edge contour of pioneer vegetation.
[0030] S3. Based on the water level data corresponding to the flooded image of the pioneer vegetation, the edge contours of the pioneer vegetation are stitched together to obtain the three-dimensional edge contours of the pioneer vegetation.
[0031] To eliminate errors caused by perspective and terrain undulation, this application employs photogrammetric processing technology. Based on the edge contours of the pioneer vegetation and the corresponding water level data of the flooded pioneer vegetation images collected from different angles, a three-dimensional spatial coordinate system is pre-constructed, and all edge contour points are subsequently transformed to this three-dimensional spatial coordinate system.
[0032] In some embodiments, step S3 includes: The edge contours of the pioneer vegetation in flooded images from different angles are associated with the corresponding water level data, and the coordinates are extracted and transformed to the same three-dimensional spatial coordinate system to obtain the three-dimensional point cloud data of the edge contours of the pioneer vegetation under the corresponding water level. The 3D point cloud data of the pioneer vegetation edge contour under different water levels are stitched and fused to obtain the 3D edge contour of the pioneer vegetation.
[0033] Furthermore, after obtaining the three-dimensional edge contour of the pioneer vegetation, the method further includes: checking the three-dimensional edge contour of the pioneer vegetation, deleting isolated and overlapping contours with high redundancy or conflict with the overall topology, and generating a continuous, complete and conflict-free three-dimensional distribution boundary of the pioneer vegetation as the final three-dimensional edge contour of the pioneer vegetation.
[0034] S4. Extract elevation point cloud data based on the three-dimensional edge contour of the pioneer vegetation, and reconstruct the three-dimensional model of the pioneer vegetation morphology based on the elevation point cloud data. In some embodiments, the elevation point cloud data can be imported into 3D modeling software to obtain a reconstructed 3D model of pioneer vegetation morphology, and the 3D morphology model can be a digital surface model (DSM).
[0035] S5. Based on the three-dimensional model of the pioneer vegetation morphology, calculate the measurement results of the pioneer vegetation morphology; wherein the measurement results of the pioneer vegetation morphology include the height, volume and biomass of the pioneer vegetation.
[0036] Application examples: such as Figures 1 to 5 As shown in this embodiment, the method for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning includes the following steps: Step S1: Construct a container for mounting the network camera, spatially arrange and fill it with pioneer vegetation and sand, and connect it to a tidal simulation device, such as... Figure 2 As shown. Its operating period is from 0:00 to 24:00 every day, recording images of flooded pioneer vegetation in coastal salt marshes at 3-minute intervals, and automatically filtering flooded images of pioneer vegetation based on real-time water level thresholds [0.00m, 0.30m]. Figure 2 This is a side view schematic diagram of the measurement of pioneer vegetation morphology in coastal salt marshes in this embodiment; Figure 3 This is a top-view schematic diagram of the measurement of pioneer vegetation morphology in the coastal salt marsh in this embodiment.
[0037] Step S2: Supported by multiple flooded images of pioneer vegetation, reinforcement learning is performed using a pre-trained visual model (e.g., the SAM model) to achieve rapid and accurate extraction of the edge contours of pioneer vegetation in coastal salt marshes. A schematic diagram of the edge contour extraction of pioneer vegetation in coastal salt marshes is shown below. Figure 4 As shown.
[0038] Step S3: Using professional photogrammetry software such as Agisoft Metashape or Pix4Dmappe, import the flooded images of pioneer vegetation acquired from multiple perspectives and the camera parameters to eliminate errors caused by perspective differences and terrain undulations. Using existing algorithms, combine the water level data with the edge contours of the pioneer vegetation to generate 3D point cloud data. Import the results into the ArcGIS platform, and based on control points, use its spatial registration tool to perform spatial similarity transformation to unify the 3D point cloud data of the pioneer vegetation edge contours from different time periods into the same coordinate system, solving the problem of inconsistent spatial references. Then, import the processed 3D point cloud data of the pioneer vegetation edge contours into CloudCompare for processing, and stitch and integrate the 3D point cloud data of the pioneer vegetation edge contours from different time periods. Finally, use the processing tools in CloudCompare to perform topology checks and clean up the overall contour grid, delete redundant and conflicting contour segments, and finally generate a continuous and complete pioneer vegetation distribution vector boundary as the final 3D edge contour of the pioneer vegetation.
[0039] Step S4, press Figure 1 The illustrated process constructs a 3D model of the pioneer vegetation morphology in the coastal salt marsh. Elevation point cloud data is extracted based on the 3D edge contours of the pioneer vegetation. Importing this elevation point cloud data into DasViewer yields a Digital Surface Model (DSM) of the pioneer vegetation. Figure 5 As shown.
[0040] In summary, the measurement results of this application are accurate and suitable for scenarios with large areas, rapid vegetation growth and changes, and difficult measurement conditions.
[0041] Example 2: Based on Example 1, this example provides a device for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, including a processor and a storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the method according to Embodiment 1.
[0042] Example 3: Based on Example 1, this example provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in Example 1.
[0043] Example 4: Based on Example 1, this example provides a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described in Example 1.
[0044] Example 5: Based on Example 1, this example provides a computer program product, including a computer program that, when executed by a processor, implements the method described in Example 1.
[0045] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0046] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0047] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0048] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0049] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A method for measuring the morphology of pioneer vegetation in a coastal salt marsh based on tidal scanning, characterized by, include: S1. Acquire multiple consecutive images of flooded pioneer vegetation in the target intertidal zone and corresponding water level data; wherein the flooded pioneer vegetation images are acquired by imaging equipment deployed in the target intertidal zone; and the water level data are acquired using tidal level stations or by deploying water level gauges. S2. Extract the edge contour of the pioneer vegetation in the flooded image of the pioneer vegetation using a computer vision model or threshold segmentation image technology. S3. Based on the water level data corresponding to the flooded image of the pioneer vegetation, the edge contours of the pioneer vegetation are stitched together to obtain the three-dimensional edge contours of the pioneer vegetation. S4. Extract elevation point cloud data based on the three-dimensional edge contour of the pioneer vegetation, and reconstruct the three-dimensional model of the pioneer vegetation morphology based on the elevation point cloud data. S5. Based on the three-dimensional model of the pioneer vegetation morphology, calculate the measurement results of the pioneer vegetation morphology; wherein the measurement results of the pioneer vegetation morphology include the height, volume and biomass of the pioneer vegetation.
2. The method of claim 1, wherein, Step S1 includes: The shooting time interval is determined based on the tidal size and tidal level characteristics and the required vertical resolution. The pioneer vegetation in the intertidal zone is continuously photographed from at least one angle according to the time interval, multiple images containing the pioneer vegetation are obtained, and the water level data at the corresponding shooting time is marked. Based on multiple images containing pioneer vegetation and corresponding water level data, the first water level corresponding to when the pioneer vegetation begins to be submerged and the second water level corresponding to when the pioneer vegetation is completely submerged are determined. Images containing pioneer vegetation located between the first and second water levels are selected as pioneer vegetation flooded images.
3. The method according to claim 1 or 2, characterized in that, The shooting equipment deployed varies depending on the actual measurement range; drones are used for larger ranges, while cameras are used for smaller ranges.
4. The method according to claim 1, characterized in that, The image containing pioneer vegetation must be taken from an angle that includes the camera being positioned at the center of the target intertidal zone and taken from above. The image containing pioneer vegetation includes both the pioneer vegetation and the surrounding water.
5. The method according to claim 1, characterized in that, Step S2: Extract the edge contours of the pioneer vegetation in the flooded image of the pioneer vegetation using a computer vision model or threshold segmentation image technology, including: Multi-level image features are obtained by using computer vision models or threshold segmentation image technology to extract multi-level features from the flooded image of the pioneer vegetation. The initial edge contour of pioneer vegetation is obtained based on multi-level image features; The initial edge contour is refined by using an optimization module that combines vegetation texture features with spatial continuity to obtain the edge contour of pioneer vegetation.
6. The method according to claim 1, characterized in that, S3. Based on the water level data corresponding to the flooded image of the pioneer vegetation, the edge contours of the pioneer vegetation are stitched together to obtain the three-dimensional edge contours of the pioneer vegetation, including: The edge contours of the pioneer vegetation in flooded images from different angles are associated with the corresponding water level data, and the coordinates are extracted and transformed to the same three-dimensional spatial coordinate system to obtain the three-dimensional point cloud data of the edge contours of the pioneer vegetation under the corresponding water level. The 3D point cloud data of the pioneer vegetation edge contour under different water levels are stitched and fused to obtain the 3D edge contour of the pioneer vegetation.
7. The method according to claim 6, characterized in that, Step S3 also includes: After obtaining the three-dimensional edge contour of the pioneer vegetation, the three-dimensional edge contour of the pioneer vegetation is checked, and isolated and overlapping contours with high redundancy or conflict with the overall topology are deleted to generate a continuous, complete and conflict-free three-dimensional distribution boundary of the pioneer vegetation as the final three-dimensional edge contour of the pioneer vegetation.
8. A device for measuring the morphology of pioneer vegetation in coastal salt marshes based on tidal scanning, characterized in that, Including processor and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the method according to any one of claims 1 to 7.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1 to 7.
10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 7.