A variable scale map making method, device, equipment, medium and product

Abstract

The present invention relates to the technical field of computer-aided mapping, and discloses a variable-scale map making method, apparatus, device, medium, and product. The method comprises: in response to a request for partial zooming in on a map, obtaining a zoom focus position and a deformation coefficient, wherein the deformation coefficient is used to control the degree of deformation; with the zoom focus as the center, calculating the offset of each coordinate point on the map based on the distance between each coordinate point and the zoom focus and the deformation coefficient; as the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases, with the offset at the zoom focus and the map boundary being 0; and performing an offset on each coordinate point based on the offset of each coordinate point. The present invention can gradually reduce the scale from the zoom focus outward with the zoom focus as the center, thereby improving the visual effect while maintaining the original image size.

Description

Technical Field

[0001] The present invention belongs to the technical field of computer-aided mapping, and in particular relates to a variable-scale map making method, device, equipment, medium and product. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] As cities continue to expand, the scope of their maps also expands. Fixed-format maps often suffer from uneven density of real-world features. City centers often have densely populated streets and numerous points of interest, making it difficult to fully represent content and impacting map readability. Meanwhile, peripheral areas have sparse streets and fewer points of interest, resulting in excessive white space on the map, impacting the overall visual quality.

[0004] To solve the above problems, the existing technology proposes to adopt variable scale map projection, starting from a plane map with a consistent scale, and changing the scale through mathematical means. A common method is to use the transition spherical method. However, when this method is applied to rectangular maps, the streets in the city that are mainly east-west and north-south will become curved and twisted, which is obviously distorted. The overall map outline will also be deformed and no longer maintain the original rectangular shape, which is not conducive to subsequent map printing. Another common method is the local magnifying glass map projection. Although this method maintains the shape of the rectangular map outline, the elements in the deformed edge area of ​​the magnifying glass effect will be distorted and overlapped, and the transition will be sudden, which seriously affects the reading effect. Summary of the Invention

[0005] In view of this, the present invention provides a variable-scale map making method, device, equipment, medium and product, so as to improve the visual effect while maintaining the original map outline when performing variable-scale map projection on the map.

[0006] A first aspect of the present invention provides a variable scale map making method, comprising the following steps:

[0007] In response to a request for zooming in on a part of the map, obtaining a zoom focus position and a deformation coefficient, wherein the deformation coefficient is used to control a degree of deformation;

[0008] Taking the zoom focus as the center, the offset of each coordinate point on the map is calculated based on the distance between each coordinate point and the zoom focus and the deformation coefficient; as the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases, and the offset at the zoom focus and the map boundary is 0;

[0009] Each coordinate point is offset according to its offset amount.

[0010] In some embodiments, it is assumed that the lower left corner of the map is the coordinate origin, and the width and height of the map are L x and L y , the original coordinates of the coordinate point are (x, y), the coordinates of the magnified focus are (x0, y0), the deformation coefficient k∈(0,1], and the calculation formula of the offset coordinates (X, Y) is as follows:

[0011]

[0012] .

[0013] In some embodiments, the method further includes: obtaining a new magnification focus position and / or a new deformation coefficient, and re-performing the offset calculation.

[0014] In some embodiments, in response to a request for local zoom in on a map, the map is divided into uniform grids, and the density within each grid is calculated; the grids are clustered based on the density; the average density of the grids in each cluster is calculated, and the center point position of the cluster with the largest average density is recorded as the recommended zoom focus.

[0015] In some embodiments, after calculating the average density of the grids in each cluster, the clusters with the largest and smallest average densities are determined, the density difference is calculated, and the recommended deformation coefficient is determined based on the density difference.

[0016] In some embodiments, in response to a request to zoom in on a part of a map, after obtaining the zoom focus position, a scale factor is obtained based on the custom zoom area:

[0017] Generate the initial standard wireframe based on the zoom focus position. The coordinates of the four corner points of the initial standard wireframe are: ;

[0018] receiving a user's resizing operation on the initial standard wireframe to obtain a custom magnified area, namely, a deformed standard wireframe;

[0019] Calculate the deformation coefficient based on the coordinates of any corner point of the standard wireframe before and after deformation.

[0020] A second aspect of the present invention provides a variable scale map making device, comprising:

[0021] a deformation parameter acquisition module configured to obtain a zoom focus position and a deformation coefficient in response to a request for local zooming in on a map, wherein the deformation coefficient is used to control a degree of deformation;

[0022] an offset calculation module configured to calculate the offset of each coordinate point on the map based on the distance between each coordinate point and the zoom focus and the deformation coefficient, with the zoom focus as the center; as the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases, and the offset at the zoom focus and the map boundary is 0;

[0023] The deformation execution module is configured to execute an offset on each coordinate point according to the offset amount of each coordinate point.

[0024] A third aspect of the present invention provides an electronic device, comprising a processor and a memory, wherein the memory stores computer instructions, and when the computer instructions are executed by the processor, the electronic device executes the method described.

[0025] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the program implements the method described when executed by a processor.

[0026] A fifth aspect of the present invention provides a computer program product, which includes a computer program and is characterized in that when the computer program is executed by a processor, it implements the method described.

[0027] One or more of the above technical solutions have the following technical effects:

[0028] By setting coordinate point offset rules, the offset of the coordinate point increases and then decreases as the distance from the magnification focus increases, and the offset at the magnification focus and the map boundary is guaranteed to be 0. This ensures that the scale change across the entire map is smoother, while maintaining the original map size, and the visual transition is natural, without an abrupt magnifying glass effect. Furthermore, by calculating the offset of each coordinate point, a one-to-one correspondence can be found for each point on the map before and after deformation, eliminating wrinkles or cracks, meeting everyone's map reading requirements and visual effects. Furthermore, since each point has a one-to-one correspondence before and after deformation, the accuracy of the inverse operation during map measurement is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 A flow chart of a variable scale map system method provided in multiple embodiments of the present invention is shown;

[0031] Figure 2 The figure shows the change of the horizontal coordinate position of the coordinate point with the vertical coordinate y0 before and after deformation;

[0032] Figure 3 A standard wireframe schematic is shown;

[0033] Figure 4 The figure shows the effect before deformation using a grid vector diagram as an example of map data;

[0034] Figure 5 The figure shows the deformed effect of a grid vector diagram as an example of map data;

[0035] Figure 6 A schematic block diagram of a variable scale map system device provided in multiple embodiments of the present invention is shown;

[0036] Figure 7 A schematic block diagram of an example device that can be used to implement embodiments of the present invention is shown. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are for illustrative purposes only and are not intended to limit the scope of protection of the present application.

[0038] In the description of the embodiments of the present application, the term “including” and similar terms should be understood as open inclusion, that is, “including but not limited to.” The term “based on” should be understood as “at least partially based on.”

[0039] As mentioned in the background technology, existing variable-scale map projection methods have problems such as map outline deformation or poor visual effects. In order to solve the above problems, one or more embodiments of the present invention provide a variable-scale map making method that maintains a rectangular map outline. By setting a coordinate point offset rule, the offset of the coordinate point increases and then decreases as the distance from the magnification focus increases, and the offset at the magnification focus and the map boundary is guaranteed to be 0, thereby achieving a smooth and gradual change in scale while maintaining the rectangular shape of the map outline.

[0040] Figure 1 A flow chart of a variable-scale map making method 100 provided by one or more embodiments of the present invention is shown, including steps S101-S103. It should be understood that the method 100 may also include additional actions not shown.

[0041] The following describes method 100 in detail. In step S101, in response to a request for partial zooming in on a map, the zoom focus position and deformation coefficient are obtained. In step S102, with the zoom focus as the center, the offset of each coordinate point on the map is calculated based on the distance between each coordinate point and the zoom focus and the deformation coefficient. As the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases. The offset at the zoom focus and at the map boundary is zero. The deformation coefficient is used to control the degree of deformation. In step S103, each coordinate point is offset based on the offset of each coordinate point.

[0042] The map can be either a raster map or a vector map. When the map is a raster map, the corners of each grid cell are coordinate points; when the map is a vector map, the nodes of the vector graphics are coordinate points. Specifically, if the vector map contains a point layer, the point features in the point layer are coordinate points; if it contains a line layer, the nodes that make up the line features are coordinate points; and if it contains an area layer, the nodes that make up the boundaries of the area features are coordinate points.

[0043] The above method allows the scale to gradually decrease from the center of the single focal point to the edge of the map, creating a natural visual transition without an abrupt magnifying glass effect. Furthermore, while achieving a smooth scale gradient, the rectangular shape and original size of the map outline are maintained, facilitating map printing. Furthermore, by calculating the offset for each coordinate point, each point on the deformed map has a clear location. When a user needs to measure the map and specify two points to measure the distance or an area to calculate the area, the consistency of the specified points or areas on the map before and after deformation is guaranteed, thereby ensuring the accuracy of the inverse calculation during map measurement.

[0044] The above method can be applied as a plug-in to existing map-making or visualization software, or as a standalone map processing tool, without specific limitation herein. In step S101, illustratively, when the plug-in or tool is launched, it is assumed that the user intends to perform a partial zoom operation on the current map imported into the software or tool, and this is considered a response to the map partial zoom request. Exemplarily, the zoom focus position and deformation coefficient are both manually specified by the user.

[0045] In step S102, the offset is determined based on the distance between the coordinate point in the map and the zoom focus. Specifically, as the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases. The offset at the zoom focus and the map boundary is 0, so that the magnification degree at the zoom focus is the largest. As the distance from the zoom focus increases, the magnification degree gradually decreases, and after reaching the original scale, it begins to shrink, and the shrinkage degree becomes larger and larger, presenting an overall scale gradient effect, eliminating the abruptness and maintaining the shape and size of the original image.

[0046] For example, assuming the coordinates of the lower left corner of the map are (0,0), the width and height of the map are L x and L y , the original coordinates of the coordinate point are (x, y), the coordinates of the magnified focus are (x0, y0), the deformation coefficient is k, and the calculation formula of the offset coordinates (X, Y) is as follows:

[0047]

[0048] .

[0049] The value of the deformation coefficient is k∈(0,1]. The larger the deformation coefficient, the more obvious the scaling deformation.

[0050] Figure 2 The figure shows the change in the horizontal coordinate position of the coordinate point with the vertical coordinate y0 before and after deformation. The horizontal coordinate represents a series of coordinate points with the vertical coordinate y0, the red straight line represents the original horizontal coordinate, and the black curve represents the horizontal coordinate after deformation. It can be seen that the intersection of the two lines represents the horizontal coordinate at the magnified focus (x0, y0). The horizontal coordinate at the edge remains unchanged before and after map deformation. From the focus to the edge, the horizontal coordinate offset first increases and then decreases.

[0051] In step S103, after performing an offset on each coordinate point, a zoomed-in map is obtained. At this point, the user can view the zoomed-in effect. If the density of features at the zoomed-in point varies, the deformation coefficients need to be adjusted accordingly to meet the user's readability and map viewing requirements. Based on this, a new deformation coefficient is obtained, and the process returns to step S102 to recalculate the offset.

[0052] It is understandable that the magnification focus position can also be adjusted as needed, and a new magnification focus position is obtained, and the process returns to step S102 to re-execute the offset calculation.

[0053] Based on this, the user can repeatedly adjust the magnification focus position and / or deformation coefficient as needed, and repeat the above method until the user's needs are met.

[0054] Since the above method can make the map present a scale gradient effect as a whole, there is a standard wireframe on the deformed map. Within the standard wireframe, the scale is larger than the original map, and outside the standard wireframe, the scale is smaller than the original map. Figure 2 In the black curve, the point with a slope of 1 is the boundary point of the standard wireframe. Through calculation, we know that the original coordinates of the four corner points of the standard wireframe are: It can be seen that after the map size and zoom focus position are determined, the standard wireframe is fixed. The size of the standard wireframe after the map is deformed is only related to the deformation coefficient. The size of the standard wireframe will change with the change of the deformation coefficient. The smaller the deformation coefficient, the smaller the degree of zoom deformation and the smaller the standard wireframe. The larger the deformation coefficient, the greater the degree of zoom deformation and the larger the standard wireframe.

[0055] Figure 3 A standard wireframe schematic is shown. Figure 4 and Figure 5 The following images show the effects before and after the deformation. A grid vector map is used as an example of map data, with the center of the map marked as the zoom focus and the red box as the standard wireframe. It can be seen that the map within the red box appears to be magnified, while the map outside the red box appears to be zoomed out, and the scale changes smoothly from the center of the map.

[0056] Taking the map of Nanjing's main urban area as an example, with the center of Drum Tower Square as the zoom focus, the mapping area covers 28.68 kilometers east-west and 23.85 kilometers north-south. The scale before deformation is 1:30,000, and the deformation coefficient is 0.5. After deformation, the horizontal and vertical scales of the map gradually change from 1:20,000 at the zoom focus to 1:60,000 at the edges.

[0057] As mentioned above, the zoom focus position and the deformation coefficient, especially the deformation coefficient, may need to be adjusted repeatedly to obtain a satisfactory presentation effect. In order to facilitate users to improve mapping efficiency, in some embodiments, a method for automatic recommendation of the zoom focus position and the deformation coefficient is also provided. The principle is that the zoom focus position generally selects the center of the area with a high density of urban features, and the deformation coefficient is also related to the map density distribution. Therefore, it can be automatically recommended based on the map density analysis. In step S101, in response to the request for local zoom in of the map, the recommended zoom focus is obtained according to the map density distribution. Exemplarily, the method for obtaining the recommended zoom focus is: uniformly divide the map into grids and calculate the density within each grid; cluster the grids based on density; calculate the average density of the grids in each cluster, and record the center point position of the cluster with the largest average density as the recommended zoom focus.

[0058] For raster maps, texture richness can be used to measure the density within each grid. For example, the Laplacian operator is used to detect the texture of the map, and the variance of the texture features within each grid is calculated to obtain the texture richness within each grid, which is recorded as the density within the grid. The larger the variance within the grid, the greater the density within the grid.

[0059] For vector maps, the map includes layers of different feature types. Therefore, the density of each grid can be comprehensively measured based on the number of feature types and the density distribution of each feature type. For example, for each layer within a grid, kernel density analysis is used to calculate the density within each grid in each layer. For each grid, the density within the grids of different layers is weighted summed to obtain the overall density within each grid. It is understandable that kernel density analysis is mainly applicable to point features and line features. To perform kernel density analysis on area features, first convert them into line features.

[0060] In step S101, in response to a request to zoom in on a specific part of the map, a recommended deformation coefficient is obtained based on the map density distribution. Specifically, the recommended deformation coefficient is determined based on the density differences on the map. For example, if there are other areas of higher density on the entire map, the deformation coefficient should not be too large, as it may cause the higher density areas to be overly compressed. Exemplarily, after performing clustering based on grid density, the clusters with the highest and lowest average densities are determined, and the density difference is calculated. The larger the density difference, the larger the recommended deformation coefficient.

[0061] As described above, the deformation coefficient can be determined through repeated testing or automatically recommended based on the map density distribution. In addition, some embodiments also provide a method for determining the deformation coefficient based on a magnified area defined by the user. The magnified area is the area within the standard wireframe. The position of the standard wireframe before deformation is only related to the focus position and the map size. Therefore, in step S101, after obtaining the focus position, an initial standard wireframe is generated; the user's size adjustment operation for the initial standard wireframe is received to obtain the magnified area desired by the user, that is, the deformed standard wireframe; and the deformation coefficient is calculated based on the coordinates of any corner point of the standard wireframe before and after deformation.

[0062] On the basis of the above-mentioned variable-scale map making method, since the scales of different places on the map sheet are different after the map is deformed, it brings difficulties to the measurement of size, area, etc. Some embodiments also provide a measurement method, which responds to a measurement request for a map after local enlargement. If the measurement request is to calculate the distance between two points, the two points are inversely operated to obtain the original coordinate positions, and the distance calculation is performed based on the original coordinate positions; if the measurement request is to calculate the area of ​​an area, the points on the boundary of the area are sampled, and the inverse operation is performed on each point to obtain the original coordinate position, and the distance calculation is performed based on the original coordinate position.

[0063] Figure 6A schematic diagram of an apparatus for executing the variable-scale map making method is shown. The apparatus 600 includes: a deformation parameter acquisition module 601, configured to obtain the zoom focus position and a deformation coefficient in response to a request for partial zooming in on a map, wherein the deformation coefficient is used to control the degree of deformation; an offset calculation module 602, configured to calculate the offset of each coordinate point on the map based on the distance between each coordinate point and the zoom focus and the deformation coefficient, with the zoom focus as the center; as the distance between the coordinate point and the zoom focus increases, the offset first increases and then decreases, and the offset at the zoom focus and the map boundary is 0; and a deformation execution module 603, configured to execute an offset on each coordinate point based on the offset of each coordinate point.

[0064] Figure 7 FIG2 shows a schematic block diagram of an example device 700 that can be used to implement one or more embodiments of the present application. The device 700 can be used to implement Figure 1 As shown in the figure, device 700 includes a computing unit 701, which can perform various appropriate actions and processes according to computer program instructions stored in random access memory (RAM) 703 and / or read-only memory (ROM) 702, or computer program instructions loaded from storage unit 708 into RAM 703 and / or ROM 702. Various programs and data required for the operation of device 700 can also be stored in RAM 703 and / or ROM 702. Computing unit 701 and RAM 703 and / or ROM 702 are connected to each other via bus 704. Input / output (I / O) interface 705 is also connected to bus 704.

[0065] Multiple components in device 700 are connected to I / O interface 705, including: an input unit 706, such as a keyboard and mouse; an output unit 707, such as various types of displays and speakers; a storage unit 708, such as a magnetic disk and optical disk; and a communication unit 709, such as a network card, a modem, a wireless communication transceiver, etc. Communication unit 709 allows device 700 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunications networks. Computing unit 701 can be various general-purpose and / or specialized processing components with processing and computing capabilities. Some examples of computing unit 701 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various computing units that run machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Computing unit 701 performs the various methods and processes described above, such as method 100. For example, in some embodiments, method 100 can be implemented as a computer software program tangibly embodied in a machine-readable medium, such as storage unit 708. In some embodiments, part or all of the computer program may be loaded and / or installed onto the device 700 via the RAM and / or ROM and / or the communication unit 709. When the computer program is loaded into the RAM and / or ROM and executed by the computing unit 701, one or more steps of the method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 701 may be configured to perform the method 100 in any other appropriate manner (e.g., via firmware).

[0066] In the above embodiments, all or part of the embodiments can be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a server or terminal, the computer program instructions fully or partially generate the processes or functions described in the embodiments of the present application. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible by the server or terminal, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., a floppy disk, hard disk, or magnetic tape), an optical medium (e.g., a digital video disk (DVD), etc.), or a semiconductor medium (e.g., a solid-state drive).

[0067] Further, while operations are depicted in a particular order, this should be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

[0068] Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details have been included in the above discussion, these should not be construed as limiting the scope of the application. Some features described in the context of a separate embodiment can also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination mode.

[0069] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A variable scale map making method, characterized in that: The following steps are involved: In response to a request to zoom in on a part of the map, after obtaining the zoom focus position, a scale factor is obtained based on the custom zoom area; Generate the initial standard wireframe based on the zoom focus position. The coordinates of the four corner points of the initial standard wireframe are: ; receiving a user's resizing operation on the initial standard wireframe to obtain a custom magnified area, namely, a deformed standard wireframe; Calculate the deformation coefficient based on the coordinates of any corner point of the standard wireframe before and after deformation, and the deformation coefficient is used to control the degree of deformation; Taking the zoom focus as the center, calculating the offset of each coordinate point on the map according to the distance between each coordinate point and the zoom focus and the deformation coefficient; Assume that the lower left corner of the map is the coordinate origin, and the width and height of the map are L x and L y , the original coordinates of the coordinate point are (x, y), the coordinates of the magnified focus are (x0, y0), the deformation coefficient k∈(0,1], and the calculation formula of the offset coordinates (X, Y) is as follows: ； Each coordinate point is offset according to its offset amount.

2. The variable scale map making method according to claim 1, wherein: The method further includes: obtaining a new magnification focus position and / or a new deformation coefficient, and re-performing the offset calculation.

3. The variable scale map making method according to claim 1, wherein: In response to a request to zoom in on a specific part of the map, the map is divided into uniform grids and the density within each grid is calculated. The grids are clustered based on the density. The average density of the grids in each cluster is calculated, and the center point of the cluster with the largest average density is recorded as the recommended zoom focus.

4. The variable scale map making method according to claim 3, wherein: After calculating the average density of the grids in each cluster, the clusters with the largest and smallest average densities are determined, the density difference is calculated, and the recommended deformation coefficient is determined based on the density difference.

5. A variable scale map making device, characterized in that: include: a deformation parameter acquisition module configured to obtain a zoom focus position in response to a request for partial zooming in on a map, and obtain a scale factor based on a custom zoomed-in area; Generate the initial standard wireframe based on the zoom focus position. The coordinates of the four corner points of the initial standard wireframe are: ; receiving a user's resizing operation on the initial standard wireframe to obtain a custom magnified area, namely, a deformed standard wireframe; Calculate the deformation coefficient based on the coordinates of any corner point of the standard wireframe before and after deformation, and the deformation coefficient is used to control the degree of deformation; an offset calculation module configured to calculate the offset of each coordinate point on the map based on the distance between each coordinate point and the zoom focus and the deformation coefficient, with the zoom focus as the center; Assume that the lower left corner of the map is the coordinate origin, and the width and height of the map are L x and L y , the original coordinates of the coordinate point are (x, y), the coordinates of the magnified focus are (x0, y0), the deformation coefficient k∈(0,1], and the calculation formula of the offset coordinates (X, Y) is as follows: ； The deformation execution module is configured to execute an offset on each coordinate point according to the offset amount of each coordinate point.

6. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein computer instructions are stored in the memory. When the computer instructions are executed by the processor, the electronic device executes the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

8. A computer program product, comprising a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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