Contour map generation method and device, computer equipment and readable storage medium

Abstract

The application relates to a contour map generation method and device and computer equipment. The method comprises the following steps: determining an effective unit surface set according to closed boundary line data and segmentation line data of a target region, wherein the effective unit surface set comprises a plurality of effective unit surfaces, and the effective unit surface is a minimum closed region formed by segmentation of the closed boundary line data and / or the segmentation line data; determining a target unit surface to which each target land use polygon belongs according to position coordinates of the target land use polygon of the target region and position coordinates of each effective unit surface; performing fusion processing on the target land use polygon contained in each target unit surface respectively to generate a target land use contour of each target unit surface; and performing spatial merging on the target land use contour of each target unit surface to generate a target land use complete contour map. Through parallel processing of each effective unit surface, processing time is effectively saved, and map processing efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of geographic information and data processing technology, and in particular to a method, apparatus, computer device and readable storage medium for generating contour maps. Background Technology

[0002] With the rapid development of computer technology and geographic information systems, electronic maps have been widely used in various industries. As one of the core geographic elements in a map, residential areas require comprehensive processing during the mapmaking process. This involves merging spatially adjacent independent buildings into building clusters to meet the visual clarity requirements of the map.

[0003] In related technologies, when comprehensively processing raw residential area data, cartographers typically need to manually compare maps and determine whether and how to merge individual buildings. This manual processing method is inefficient when dealing with massive amounts of residential area data. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer device, and readable storage medium for generating contour maps to address the aforementioned technical problems.

[0005] Firstly, this application provides a method for generating a contour map, comprising:

[0006] Based on the closed boundary line data and the dividing line data of the target area, a set of effective unit surfaces is determined. The set of effective unit surfaces includes multiple effective unit surfaces. Each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0007] Based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined;

[0008] Each target unit face contains a target land polygon that is fused to generate a target land outline for each target unit face.

[0009] The target land contours of each target unit surface are spatially merged to generate a complete target land contour map.

[0010] In one embodiment, determining the set of effective unit surfaces based on the closed boundary line data and segmentation line data of the target region includes:

[0011] The closed boundary line data and the dividing line data are divided to obtain multiple line segments and multiple intersection points;

[0012] Construct a planar connected graph using the intersection points as nodes and the line segments as edges;

[0013] For each edge in the planar connected graph, the smallest closed loop containing the edge is determined as the valid closed loop corresponding to the edge;

[0014] The closed region enclosed by the effective closed loop is defined as the effective element surface, and all effective element surfaces constitute the effective element surface set.

[0015] In one embodiment, determining the target unit face to which each target land polygon belongs, based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, includes:

[0016] For each target land polygon, the position coordinates of the target land polygon are matched with the position coordinates of each effective unit face;

[0017] If the geometric boundary of the target land polygon falls completely within the range of any valid unit surface, then the any valid unit surface is determined as the target unit surface of the target land polygon.

[0018] If the target land polygon intersects with multiple valid unit faces, the shared dividing line data among the multiple valid unit faces is removed, and the area after merging the multiple valid unit faces is determined as the target unit face of the target land polygon.

[0019] In one embodiment, the step of fusing the target land polygons contained in each target unit face to generate the target land outline of each target unit face includes:

[0020] The map accuracy tolerance, map outline size threshold, scale parameters, and dimension conversion coefficients are processed to determine the first distance threshold;

[0021] Each of the target land polygons is expanded outward according to the first distance threshold to generate a first polygon, and multiple first polygons that have an intersection relationship are merged to obtain a second polygon;

[0022] The joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding target land use outline. The joint polygon includes the second polygon and the first polygon that does not intersect.

[0023] In one embodiment, the step of expanding each of the target land polygons outward according to the first distance threshold to generate a first polygon includes:

[0024] For each target land polygon with internal holes, the target land polygon is expanded outward in the target direction corresponding to each boundary line according to the first distance threshold, and the internal holes are shrunken inward in the target direction corresponding to each boundary line according to the first distance threshold to generate a first polygon.

[0025] In one embodiment, the step of shrinking the joint polygon inward according to the first distance threshold to obtain the corresponding target land use outline includes:

[0026] If any of the joint polygons has an internal hole, the joint polygons are shrunk inward according to the first distance threshold, and the internal hole is expanded outward according to the first distance threshold to obtain the corresponding candidate land use outline.

[0027] If the candidate land use outline contains internal holes and the area of ​​the internal holes is less than a preset threshold, the internal holes are filled to obtain the corresponding target land use outline; or, if the candidate land use outline does not contain internal holes, or the area of ​​the internal holes is greater than or equal to the preset threshold, the candidate land use outline is determined as the target land use outline.

[0028] In one embodiment, the step of shrinking the joint polygon inward according to the first distance threshold to obtain the corresponding target land use outline includes:

[0029] Each joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding third polygon;

[0030] The third polygon is shrunk inward according to the second distance threshold to obtain the fourth polygon, where the second distance threshold is less than the first distance threshold.

[0031] The fourth polygon is expanded outward according to the second distance threshold to obtain the target land outline.

[0032] Secondly, this application also provides an apparatus for generating a contour map, comprising:

[0033] The first determining module is used to determine a set of effective unit surfaces based on the closed boundary line data and the dividing line data of the target area. The set of effective unit surfaces includes multiple effective unit surfaces, and each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0034] The second determining module is used to determine the target unit face to which each target land polygon belongs based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face;

[0035] The first generation module is used to merge the target land polygons contained in each target unit face to generate the target land outline of each target unit face.

[0036] The second generation module is used to spatially merge the target land contours of each target unit surface to generate a complete target land contour map.

[0037] Thirdly, this application also 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 perform the following steps:

[0038] Based on the closed boundary line data and the dividing line data of the target area, a set of effective unit surfaces is determined. The set of effective unit surfaces includes multiple effective unit surfaces. Each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0039] Based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined;

[0040] Each target unit face contains a target land polygon that is fused to generate a target land outline for each target unit face.

[0041] The target land contours of each target unit surface are spatially merged to generate a complete target land contour map.

[0042] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0043] Based on the closed boundary line data and the dividing line data of the target area, a set of effective unit surfaces is determined. The set of effective unit surfaces includes multiple effective unit surfaces. Each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0044] Based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined;

[0045] Each target unit face contains a target land polygon that is fused to generate a target land outline for each target unit face.

[0046] The target land contours of each target unit surface are spatially merged to generate a complete target land contour map.

[0047] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0048] Based on the closed boundary line data and the dividing line data of the target area, a set of effective unit surfaces is determined. The set of effective unit surfaces includes multiple effective unit surfaces. Each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0049] Based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined;

[0050] Each target unit face contains a target land polygon that is fused to generate a target land outline for each target unit face.

[0051] The target land contours of each target unit surface are spatially merged to generate a complete target land contour map.

[0052] The aforementioned method, apparatus, computer equipment, and readable storage medium for generating the contour map can first determine a set of effective unit faces based on the closed boundary line data and dividing line data of the target area. The set of effective unit faces includes multiple effective unit faces, and each effective unit face is the smallest closed area formed by dividing line data and / or closed boundary lines. Then, based on the position coordinates of the target land polygons in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined. The target land polygons contained in each target unit face are then merged to generate the target land contour of each target unit face. Finally, the target land contours of each target unit face can be spatially merged to generate a complete contour map of the target land. Therefore, by using the closed boundary line and dividing line of the target area to divide it into multiple effective unit surfaces, and dividing it into independent processing zones based on road data, the effective unit surfaces corresponding to each target land polygon are determined by coordinate matching. The target land polygons are then fused independently within each effective unit surface. Finally, the residential outlines of single blocks are spatially merged to obtain a complete outline map of the target land. In this process, because the data of each effective unit surface is independent, the fusion processing of target land polygons can be performed on multiple effective unit surfaces in parallel, thereby effectively saving the overall processing time and improving the efficiency of map comprehensive processing. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating a method for generating a contour map in one embodiment;

[0055] Figure 2 This is a schematic diagram of multi-source data in one embodiment;

[0056] Figure 3 This is a flowchart illustrating a method for generating a contour map in another embodiment;

[0057] Figure 4 This is a schematic diagram of the dividing line data and the effective cell surface in one embodiment;

[0058] Figure 5 This is a schematic diagram of the effective unit surfaces at different scales in one embodiment;

[0059] Figure 6 This is a schematic diagram of the residential land polygon and the street block unit face in one embodiment;

[0060] Figure 7 This is a schematic diagram of the complete outline of the target land use in one embodiment;

[0061] Figure 8 This is a schematic diagram illustrating the process of generating the target land use outline of the target unit surface in one embodiment;

[0062] Figure 9 A schematic diagram of the target land use polygon and the first polygon in one embodiment;

[0063] Figure 10 This is a schematic diagram of the second polygon in one embodiment;

[0064] Figure 11 This is a schematic diagram of the target land polygon and the first polygon in another embodiment;

[0065] Figure 12 This is a schematic diagram of the combined polygon and the outline of the target land use in one embodiment;

[0066] Figure 13 This is a schematic diagram of the combined polygon and the outline of the target land use in another embodiment;

[0067] Figure 14 This is a schematic diagram of a joint polygon in one embodiment;

[0068] Figure 15 This is a schematic diagram of the third polygon and the outline of the target land use in one embodiment;

[0069] Figure 16 This is a schematic diagram illustrating the process of generating a residential outline map in one embodiment;

[0070] Figure 17 This is a structural block diagram of a contour map generation device in one embodiment;

[0071] Figure 18 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0073] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0074] In one embodiment, such as Figure 1 As shown, a method for generating a contour map is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and further to a system including both a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0075] Step 102: Based on the closed boundary line data and segmentation line data of the target area, determine the set of effective unit surfaces. The set of effective unit surfaces includes multiple effective unit surfaces. An effective unit surface is the smallest closed region formed by segmentation line data and / or closed boundary line data.

[0076] The target area can be understood as the specified geographic space range for which an outline map needs to be generated. In practical applications, the target area can be an area within the administrative boundary, a specified watershed range, or an urban planning red line area, etc. This application does not limit this.

[0077] In addition, the closed boundary line data can be the outer geometric boundary line of the target area, which can be used to define the overall boundary. For example, it can be the administrative division boundary line, the planning boundary of the project construction land red line, the natural geographical boundary line such as the river shoreline, etc. This application does not limit it.

[0078] In addition, the dividing line data may include road centerlines of various levels distributed within the target area, which may include expressways, national highways, provincial highways, urban expressways, urban arterial roads, secondary arterial roads, branch roads, rural roads or field roads, etc., and this application does not limit them.

[0079] Optionally, when integrating land use, in order to make the division of unit surfaces more in line with the actual terrain, the dividing line data may also include one or more of the following: water system lines, ditch lines, boundary lines or ridge lines. This application does not limit this.

[0080] It is understood that in the embodiments of this application, both the dividing line data and the closed boundary line data belong to linear geographic features. An effective unit surface can be the smallest closed polygon formed by the division of linear geographic features. For example, the effective unit surface can be the smallest closed area formed by the mutual intersection of the dividing line data itself, or it can be the smallest closed area formed by the division of the dividing line data and the closed boundary line data, etc. For ease of description, this application uses road lines as an example for illustration. Figure 2 (a) shows the road line data. Figure 2 (b) For closed boundary line data, in the process of determining the effective unit surface, the spatial reference of the road line data and the closed boundary line data can be unified first, and a consistent projection coordinate system can be used to avoid topological offset caused by coordinate system misalignment in the subsequent spatial analysis process, which would affect the subsequent data processing.

[0081] Therefore, in this embodiment of the application, a large target area can be divided into several spatially independent computational partitions, i.e. effective unit surfaces, by utilizing objectively existing closed boundary line data and segmentation line data, thus providing a data foundation for subsequent distributed parallel computing.

[0082] Step 104: Determine the target unit face to which each target land polygon belongs based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face.

[0083] Among them, the target land use polygon can be a geometric polygon with a closed boundary in space, which can be used to represent land use patches that are discrete or discontinuously distributed within the target area.

[0084] For example, in residential area contour extraction, the target land use polygon can be the building base polygon of the residential area or the patch polygon of the residential area, etc. Figure 2 (c) is a residential land polygon; for farmland contour extraction, the target land polygon can be a farmland polygon or an agricultural planting patch, etc.; for commercial land contour extraction, the target land polygon can be a commercial building base polygon or a shop plot polygon, etc., and this application does not limit this.

[0085] Understandably, before determining the target unit to which each target land polygon belongs, the spatial references of the target land polygons of the target area, the dividing line data, and the closed boundary line data can be unified, and a consistent projected coordinate system can be adopted to ensure the consistency of data processing.

[0086] Optionally, in the process of determining the target unit face to which each target land polygon belongs, the spatial relationship between the target land polygon and each effective unit face can be calculated.

[0087] In one possible implementation, the coordinates of each vertex of the target land polygon can be matched with the area enclosed by each effective unit face. If the coordinates of all vertices of the target land polygon are located in the area enclosed by a certain effective unit face, then that effective unit face can be used as the target unit face corresponding to the target land polygon.

[0088] Alternatively, to improve data error tolerance, the geometric centroid or centroid coordinates of the target land polygon can be calculated. If the geometric centroid coordinates fall within the range of a certain effective unit surface, then that effective unit surface can be determined as the target unit surface corresponding to the target land polygon.

[0089] It should be noted that the above examples are merely illustrative and should not be construed as limiting the methods for determining the target unit surface corresponding to the target land polygon in the embodiments of this application.

[0090] Therefore, in this embodiment of the application, a mapping relationship between land use polygons and grid-like effective unit surfaces can be established by spatial coordinate matching, converting multi-component target land use polygons into target unit surfaces containing only single elements, thereby transforming the complex global data retrieval task into local grouping and classification, thus effectively reducing the computational load.

[0091] Step 106: Merge the target land polygons contained in each target unit face to generate the target land outline of each target unit face.

[0092] For each target unit surface, all target land polygons contained within that target unit surface can be obtained first. If two or more target land polygons within the same target unit surface meet the fusion conditions, then these target land polygons can be merged to generate a merged target land polygon. The fusion conditions can be varied, such as the target land polygons intersecting in space, their boundaries coinciding, or the closest spatial distance between two target land polygons being less than a set distance threshold, etc. This application does not limit these conditions.

[0093] Through the above fusion, the merged target land polygon generated after fusion, as well as the independent target land polygons within the target unit surface that do not need to be merged, are retained and used together as the target land outline of the target unit surface.

[0094] Therefore, in this embodiment, by performing local polygon fusion within independent target unit faces, the fusion operation is confined within the road network barrier boundaries, ensuring that the generated boundaries of residential areas, farmland, or commercial areas do not encroach on public roads, thus guaranteeing the spatial rationality of the contour map. Since the data within each target unit face is independent, multi-threaded parallel computation can be supported, thereby significantly reducing the processing time of the fusion process.

[0095] Step 108: Spatially merge the target land contours of each target unit surface to generate a complete target land contour map.

[0096] This process involves consolidating the target land use outlines corresponding to each target unit facet into a single spatial database or spatial data layer. Through layer assembly or spatial merging operations, a complete outline map of the target land use covering the entire target area is formed. Since the target land use outlines of each target unit facet have been determined separately, spatial merging is performed by overlaying and assembling data at the data level. This effectively avoids direct global polygon fusion under large-scale map data, improving the stability and efficiency of data processing.

[0097] In the above method for generating the contour map, the effective unit surface set can be determined first based on the closed boundary line data and dividing line data of the target area. The effective unit surface set includes multiple effective unit surfaces, and the effective unit surface is the smallest closed area formed by dividing line data and / or closed boundary line data. Then, based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit surface, the target unit surface to which each target land polygon belongs can be determined. Then, the target land polygons contained in each target unit surface are fused separately to generate the target land contour of each target unit surface. Finally, the target land contours of each target unit surface can be spatially merged to generate a complete contour map of the target land. Therefore, by using the closed boundary line and dividing line of the target area to divide it into multiple effective unit surfaces, and dividing it into independent processing zones based on road data, the effective unit surfaces corresponding to each target land polygon are determined by coordinate matching. The target land polygons are then fused independently within each effective unit surface. Finally, the residential outlines of single blocks are spatially merged to obtain a complete outline map of the target land. In this process, because the data of each effective unit surface is independent, the fusion processing of target land polygons can be performed on multiple effective unit surfaces in parallel, thereby effectively saving the overall processing time and improving the efficiency of map comprehensive processing.

[0098] In one exemplary embodiment, such as Figure 3 As shown, the method for generating the contour map may include steps 302 to 312. Wherein:

[0099] Step 302: Based on the closed boundary line data and segmentation line data of the target area, determine the set of effective unit surfaces. The set of effective unit surfaces includes multiple effective unit surfaces. An effective unit surface is the smallest closed region formed by segmentation line data and / or closed boundary line data.

[0100] Optionally, the closed boundary line data and the dividing line data can be segmented to obtain multiple line segments and multiple intersection points. Then, a planar connected graph can be constructed with the intersection points as nodes and the line segments as edges. For each edge in the planar connected graph, the smallest closed loop containing that edge is determined as the valid closed loop corresponding to the edge. The closed region enclosed by the valid closed loops is determined as the valid unit surface. All valid unit surfaces form a set of valid unit surfaces.

[0101] Intersection calculations can be used to determine all spatial intersections between closed boundary line data and dividing line data. At these intersections, topological breaks can be performed on the closed boundary line data and dividing line data, splitting them into multiple independent physical line segments that are connected end to end but do not intersect each other.

[0102] Furthermore, for any edge in a planar connected graph, there may be one or more closed loops containing that edge. If there is only one closed loop containing a certain edge, that closed loop can be determined as the valid closed loop for that edge. If there are multiple closed loops containing a certain edge, the perimeter of each closed loop can be calculated separately, and the closed loop with the smallest perimeter can be determined as the valid closed loop corresponding to that edge. The above process can be simplified as follows:

[0103] ;

[0104] in, The final set of effective closed loops, which can also be called the effective street face set in a street block, is the final set of effective closed loops. This indicates that, given a given edge, a closed cycle with the smallest perimeter containing that edge is selected. This indicates a search within the set C(G) of all closed cycles generated by the connected graph G. This indicates the calculation of the perimeter of closed loop B, C. k Let be the edge on the ring.

[0105] For example, such as Figure 4 (a) shows a partial diagram of the segmentation line data. The closed boundary line and road data line are segmented, and the resulting effective unit surface is as follows: Figure 4 As shown in (b).

[0106] Optionally, for the target map to be generated, different levels of roads can be selected according to its display scale or analysis requirements to generate effective unit surfaces of different aggregation levels.

[0107] For example, if a high-resolution micro-street scene like 1:1000 is required, all levels of roads can be preserved, including side streets and alleyways. After processing, this can generate a micro-street scene like... Figure 5 (a) shows the effective unit surfaces corresponding to the micro-blocks, which are small in area, numerous in number, and complex in structure.

[0108] If a medium resolution, such as 1:5000, is required for regular street layouts, low-level road networks, such as side roads and alleys, can be dynamically removed using attribute filters, retaining only secondary arterial roads and above. Then, surface processing can be performed on these roads, resulting in layouts like... Figure 5 (b) shows that the effective unit surface corresponding to the regular street block has a relatively large area and a more macroscopic visual structure, thus avoiding excessive fragmentation while maintaining the basic road network structure of the area.

[0109] If a lower resolution core street surface is required, secondary roads can be further eliminated, retaining only main roads, expressways, and other high-level road networks for surface construction. This generates effective unit surfaces corresponding to the core street, significantly expanding the street surface, simplifying internal details, and resulting in a clearer and more macroscopic visual appearance. For example, for 1:2000 and 1:3000 resolutions, the effective unit surfaces corresponding to the generated street surfaces can be as follows: Figure 5 As shown in (c) and 5(d).

[0110] If a macro overview is required, the outer closed boundary polygon of the target area can be used as an independent large surface, without distinguishing the internal blocks, and only the macro outline is presented to ensure the visual clarity and readability of the map.

[0111] Therefore, in this embodiment of the application, the minimum perimeter closed loop algorithm can be used to extract all the minimum physical interval grids, i.e., effective unit surfaces, from large-scale map data with intricate road network relationships, thereby ensuring the reliability and scientific nature of the effective unit surfaces as much as possible.

[0112] Step 304: For each target land polygon, match the position coordinates of the target land polygon with the position coordinates of each valid unit face.

[0113] In the process of matching the location coordinates of the target land polygon with the location coordinates of each effective unit face, spatial index matching or spatial inclusion relationship of geometric boundaries can be used.

[0114] For example, the coordinates of the vertices, centroid, centroid, or minimum bounding rectangle of each target land polygon can be obtained and compared with the vertex coordinate range of each effective unit face to filter out effective unit faces that have spatial overlap, inclusion, or intersection with the target land polygon.

[0115] Therefore, in this embodiment of the application, by using filtering and matching based on spatial coordinates and spatial indexes, the calculation range and pairing range can be quickly narrowed in the global massive data, avoiding useless global topology calculations, thereby greatly improving the computational efficiency of spatial mapping processing.

[0116] Step 306: If the geometric boundary of the target land polygon falls completely within the range of any valid unit surface, then the valid unit surface is determined as the target unit surface of the target land polygon.

[0117] If all boundary nodes and internal regions of the geometric boundary of the target land polygon are spatially contained within the geometric boundary line of a single effective unit surface, that is, there is no boundary crossing or intersection relationship between the two, the geometric boundary of the target land polygon can be considered to fall completely within the range of the effective unit surface, and then the effective unit surface can be determined as the target unit surface of the target land polygon, etc. This application does not limit this.

[0118] Therefore, in this embodiment of the application, for conventional target land polygons that are located within a single road grid and do not cross roads, the unit mapping and affiliation can be established through inclusion relationships, making the subsequent division of calculation units more intuitive and efficient.

[0119] Step 308: If the target land polygon intersects with multiple valid unit faces, the shared dividing line data between the multiple valid unit faces is removed, and the area after merging the multiple valid unit faces is determined as the target unit face of the target land polygon.

[0120] If the target land polygon intersects with multiple valid unit faces, meaning the target land polygon spans multiple valid unit faces, then the shared dividing line data between these multiple valid unit faces can be identified and removed from the data, that is, the dividing line segments of the common internal boundaries between multiple valid unit faces can be eliminated. Afterwards, these valid unit faces can be spatially merged into a large joint unit face, which serves as the final target unit face for the target polygon.

[0121] For example, in a residential area scenario, the target land use polygon can be a residential land polygon, and the effective unit facets can be street unit faces. Each street unit facet has a corresponding unique identifier, Area ID. For each residential land polygon, it can be spatially matched with each effective unit facet.

[0122] If the geometric boundary of a residential polygon falls entirely within a block unit face, then the Area ID of that block unit face can be assigned to the residential polygon; this block unit face is then considered a valid unit face of the residential polygon. Figure 6 The yellow residential polygon, which falls entirely within a certain block unit face, can be assigned the identifier of the block unit face it belongs to.

[0123] If a residential polygon intersects with multiple street block faces, i.e., spans multiple street block faces, such as... Figure 6 The red polygon spans two street unit faces. The dividing line data shared by the two street unit faces can be removed, and the two street unit faces can be merged into a joint unit face. The identifier of the joint unit face is assigned to the residential polygon, and the joint unit face is the effective unit face of the residential polygon.

[0124] In this embodiment, the massive number of mapped residential polygons can be divided into independent data groups using the unique area ID as the key. Since the area unit faces are separated by road networks with physical widths, the residential polygons within each area unit face do not intersect each other in spatial topology, forming a spatial computing sandbox, and the residential polygons are divided into different area unit faces.

[0125] Therefore, in this embodiment of the application, by using a partitioning method based on road constraints, it is ensured that spatially independent and small-area patches will not be blindly and indiscriminately connected across roads, while also ensuring that single large geographic entities that cross roads, such as large factory areas or large areas of farmland, will not be forcibly fragmented in subsequent fusion calculations, thus effectively preserving the integrity of geographic spatial entities.

[0126] Step 310: Merge the target land polygons contained in each target unit face to generate the target land outline of each target unit face.

[0127] Step 312: Spatially merge the target land contours of each target unit surface to generate a complete target land contour map.

[0128] It is understandable that after generating the target land use outline for each target unit surface, the target land use outlines of each target unit surface can be spatially merged to generate, as shown below. Figure 7 The complete outline map of the target land shown only schematically illustrates a portion of the area.

[0129] In this embodiment, a set of effective unit surfaces can be determined first based on the closed boundary line data and dividing line data of the target area. The set of effective unit surfaces includes multiple effective unit surfaces, which are the smallest closed areas formed by dividing line data and / or closed boundary line data. For each target land polygon, the position coordinates of the target land polygon are matched with the position coordinates of each effective unit surface. If the geometric boundary of the target land polygon falls completely within the range of any effective unit surface, that effective unit surface is determined as the target unit surface of the target land polygon. If the target land polygon intersects with multiple effective unit surfaces, the dividing line data shared by multiple effective unit surfaces is removed, and the area after merging multiple effective unit surfaces is determined as the target unit surface of the target land polygon. Then, the target land polygons contained in each target unit surface can be fused separately to generate the target land contour of each target unit surface. Finally, the target land contours of each target unit surface are spatially merged to generate a complete outline map of the target land. Therefore, by using dividing lines and closed boundary lines, the target area is divided into multiple effective unit faces. Coordinate matching is used to distinguish the ownership of land use polygons. Each unit face is used as the basic processing unit for independent fusion, and then spatial merging is used to generate a complete outline map. Since each effective unit face is independent of the others, parallel computing can be used to process them simultaneously, thereby effectively improving processing efficiency. Using dividing lines as boundaries ensures that the fusion result does not cross roads, guaranteeing topological correctness. For target land use polygons that span multiple unit faces, their integrity is maintained by merging unit faces, effectively improving the efficiency and quality of target land use outline map generation.

[0130] In one exemplary embodiment, such as Figure 8 As shown, step 106 includes steps 802 to 806. Wherein:

[0131] Step 802: Process the map accuracy tolerance, map outline size threshold, scale parameters and dimension conversion coefficients to determine the first distance threshold.

[0132] Among them, the map accuracy tolerance can be the map accuracy tolerance of the outline map to be generated, which can represent the accuracy threshold of the smallest map area or spacing that the human eye or output device can distinguish under the current map cartographic specifications; the map outline size threshold can represent the physical line width or basic graphic size constraints of geographical symbols such as buildings during map rendering; the scale parameter can be the scale denominator of the outline map to be generated, as a dimensionless scaling factor, which can be used to linearly enlarge the visual size of the map to the real geographic space; the dimension conversion coefficient is the spatial scale dimension conversion coefficient, which can be used to equivalently convert the physical size (mm) of the map after scale enlargement to the standard unit (m) used by the underlying geographic coordinate system; the first distance threshold can satisfy the following relationship:

[0133] ;

[0134] in, To accommodate map accuracy tolerance, is the map outline size threshold, S is the scale parameter, and 1000 is the dimension conversion factor.

[0135] Therefore, in this embodiment of the application, the first distance threshold for polygon expansion and contraction at the current scale can be obtained by combining the above parameters, thereby achieving adaptive fusion processing at different scales.

[0136] Step 804: Expand each target land polygon outward according to the first distance threshold to generate a first polygon, and merge multiple first polygons that have an intersection relationship to obtain a second polygon.

[0137] After determining the first distance threshold, each target land polygon can be expanded outward according to the first distance threshold to obtain a first polygon that corresponds one-to-one with each target land polygon after expansion. Due to the forward expansion, some adjacent first polygons may spatially intersect or overlap. Multiple first polygons that intersect or are physically in contact are spatially merged to obtain the corresponding second polygon. For example, if first polygon 1 and first polygon 2 intersect, they can be merged to obtain second polygon 1; if first polygon 3, first polygon 4, and first polygon 5 intersect, they can be merged to obtain second polygon 2.

[0138] For example, for such Figure 9 The target land polygon shown in (a) is expanded outward according to a first distance threshold to obtain the following result: Figure 9 (b) shows the first polygon formed after expansion. Multiple first polygons that have intersection relationships are merged to obtain the following: Figure 10 The second polygon shown.

[0139] Therefore, in this embodiment of the application, by expanding the target polygon outward, spatially adjacent independent polygons are geometrically contacted or overlapped; then all generated first polygons are retrieved, and polygons with spatial intersection or overlap are geometrically merged to eliminate overlapping boundaries, so that the originally discrete adjacent buildings are merged into a whole building group polygon, and the corresponding second polygon is obtained.

[0140] Optionally, for each target land polygon with internal holes, the target land polygon can be expanded outward in the target direction corresponding to each boundary line according to a first distance threshold, and the internal holes can be contracted inward in the target direction corresponding to each boundary line according to the first distance threshold to generate the first polygon.

[0141] The target direction can be a direction perpendicular to the boundary line of the target land polygon, also known as the normal direction of the boundary line, or it can be a direction perpendicular to the boundary line of the internal hole, also known as the normal direction of the boundary line.

[0142] Optionally, if the target land polygon is detected to contain an outer ring (counterclockwise) and at least one inner ring (clockwise), it can be determined that the target land polygon has an internal hole.

[0143] Furthermore, during the generation of the first polygon, a positive buffer with a first distance threshold can be established outside the corresponding normal of the target land polygon, using the geometric boundary of the target land polygon as a reference. The generated positive buffer is then combined with the target land polygon. Simultaneously, a negative buffer with a first distance threshold is established inside the normal of the internal hole, using the boundary line of the internal hole as a reference. The generated negative buffer is then combined with the internal hole, resulting in the first polygon with an expanded outer boundary and a contracted internal hole. For example, for Figure 11 (a) shows a target land polygon with internal holes. After expanding the outer boundary outward and contracting the holes inward, it generates a shape like this. Figure 11 The first polygon shown in (b).

[0144] Therefore, in this embodiment, for the target land polygon, a positive buffer expansion based on normals is performed outward to make the adjacent small polygons in physical space geometrically contact each other, providing a data foundation for fusion. For the target land polygon with internal holes, inward contraction is performed to ensure that the internal holes will not be distorted due to irregular deformation during the outward expansion of the target land polygon, effectively preserving the original attributes of the land features.

[0145] Step 806: The joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding target land contour. The joint polygon includes the second polygon and the first polygon that does not intersect.

[0146] The combined polygon can include independent first polygons that do not intersect or overlap, and a second polygon obtained by merging them. For each polygonal unit in the combined polygon, an inward contraction process is performed along the normal direction of each boundary line according to a first distance threshold. This inward contraction offsets the scale shift caused by outward expansion according to the first distance threshold, thereby restoring the external boundary of the combined polygon to the actual spatial footprint while completing the geometric merging of neighboring polygons, thus restoring the true scale of the building complex and obtaining the corresponding target land use outline. Figure 12 The joint polygon shown in (a), when shrunk inward, yields the following: Figure 12 (b) shows the target land use outline.

[0147] Optionally, if any joint polygon has an internal hole, the joint polygon can be shrunk inward according to a first distance threshold, and the internal hole can be expanded outward according to the first distance threshold to obtain the corresponding candidate land use outline; if the candidate land use outline has an internal hole and the area of ​​the internal hole is less than a preset threshold, the internal hole is filled to obtain the corresponding target land use outline; or, if the candidate land use outline does not have an internal hole, or the area of ​​the internal hole is greater than or equal to the preset threshold, the candidate land use outline is determined as the target land use outline.

[0148] Specifically, for a combined polygon with internal holes, the polygon can be negatively buffered inward in the target directions corresponding to each boundary line according to a first distance threshold. Simultaneously, for the internal holes, positively buffered outward in the target directions corresponding to their boundary lines according to the first distance threshold, resulting in a candidate land use outline after external boundary contraction and internal hole expansion. During this contraction and expansion process, the relative position and proportion of the holes remain unchanged, effectively maintaining the relative spatial relationship between the holes and the main area, restoring and preserving the typical characteristics of the areal elements, and avoiding geometric distortion. For example, in... Figure 13 The joint polygon shown in (a) can be shrunk inward according to a first distance threshold, and the two existing internal holes can be expanded outward according to the first distance threshold, resulting in the following: Figure 13 (b) shows the candidate land use outline.

[0149] Furthermore, the preset threshold can be a pre-defined area value, or it can be adjusted according to actual needs, etc., and it can be used to distinguish between holes that are significant for preservation and small holes that can be ignored. This application does not limit this.

[0150] For example, if the area of ​​an internal hole in the candidate land use outline is greater than or equal to a preset threshold, it can be considered that the internal hole has a sufficiently large scale in physical space and usually has actual geographical significance. Directly filling or deleting it may lead to the loss of spatial information and affect the accuracy of subsequent processing. Therefore, the internal hole can be retained. If the area of ​​an internal hole in the candidate land use outline is less than the preset threshold, it can be considered that the internal hole does not have actual geographical significance in physical space and can be directly filled or deleted. This application does not impose any restrictions on this.

[0151] For each candidate land use outline, the coordinates of each boundary vertex of its internal holes can be extracted, and the area of ​​the closed inner ring region can be calculated to determine the relationship between the area and a preset threshold.

[0152] If the area of ​​the internal hole is less than a preset threshold, it can be considered a small topological crack without actual geographical significance. It can be filled to eliminate visual fragmentation and obtain the outline of the target land after filling. If the area of ​​the internal hole exceeds the preset threshold, it can be considered to have a sufficiently large scale in physical space and actual geographical significance. If it is filled or deleted directly, it may lead to the loss of spatial information. Therefore, it can be retained to truly restore the typical morphological characteristics of the settlement.

[0153] like Figure 14 (a) shows a candidate land use outline containing two internal holes. The area of ​​the left internal hole is less than a preset threshold, while the area of ​​the right internal hole is greater than a preset threshold. The left internal hole can be filled, and the right internal hole can be retained, resulting in the following: Figure 14 (b) shows the filled target land outline.

[0154] Therefore, by filling in small holes with excessively small areas while retaining large holes, it is possible to avoid too many trivial blank areas in the final outline map, effectively improving the visual clarity of the map while ensuring that the geographical information is not distorted.

[0155] Optionally, after shrinking the joint polygons inward according to the first distance threshold, in order to further eliminate any narrow bridges or sharp burrs that may exist on the boundary, each joint polygon can be shrunk inward according to the first distance threshold to obtain the corresponding third polygon, and the third polygon can be shrunk inward according to the second distance threshold to obtain the fourth polygon. The second distance threshold is less than the first distance threshold. Then, the fourth polygon is expanded outward according to the second distance threshold to obtain the target land outline.

[0156] The second distance threshold is a pre-set value that is much smaller than the first distance threshold. It can be used to remove visually meaningless narrow bridges or sharp burrs that remain after merging.

[0157] In this process, each joint polygon is shrunk inward along the target direction corresponding to each boundary line according to a first distance threshold. This process cancels out the scale shift caused by expanding outward according to the first distance threshold. This allows the external boundary of the joint polygon to be restored to the actual spatial footprint while completing the geometric merging of neighboring polygons, thus restoring the true scale of the building complex and obtaining the corresponding third polygon.

[0158] Next, the third polygon is shrunk inward along the target directions corresponding to each boundary line according to the second distance threshold to obtain the fourth polygon. Then, the fourth polygon is expanded outward along the target directions corresponding to each boundary line according to the second distance threshold to obtain the target land use outline. For example, in... Figure 15 The third polygon shown in (a) can be obtained by contracting inward and expanding outward, as shown in the figure. Figure 15 (b) shows the target land use outline.

[0159] Understandably, after the first distance threshold expansion and contraction are completed, boundary noise such as slender hanging edges or isolated sharp burrs, caused by computational geometric approximation, is easily generated at the turning points of the polygon boundaries. By using a small-scale second distance threshold for opening operations, without damaging the main scale and fusion shape of the polygon, tiny adhesion gaps and fine burr-like protrusions at the edges are eliminated, making the final generated target land contour smoother and effectively improving the quality of the contour map.

[0160] Optionally, if a third polygon completely disappears during the inward contraction process according to the second distance threshold, the inward contraction and outward expansion of the third polygon will no longer be carried out according to the second distance threshold, and the original outline of the third polygon will still be retained. This avoids the accidental deletion of small, real, independent building areas during the cleaning of narrow sides, and effectively ensures data quality.

[0161] Therefore, in this embodiment, by shrinking the joint polygon inward and expanding it outward, a morphological opening operation is achieved, smoothly integrating fragmented patches while maintaining a generally consistent area. By filtering and filling micro-holes before shrinking, map noise can be reduced. At the same time, by performing opening operations at two different scales, the boundary vertices and burrs are further refined. No manual image processing is required, greatly improving the convenience and reliability of cartography.

[0162] In this embodiment, the map accuracy tolerance, map outline size threshold, scale parameters, and dimension conversion coefficients are first processed to determine a first distance threshold. Then, each target land polygon is expanded outward according to the first distance threshold to generate a first polygon. Multiple first polygons with intersecting relationships are merged to obtain a second polygon. Finally, the combined polygon is shrunk inward according to the first distance threshold to obtain the corresponding target land outline. The combined polygon includes the second polygon and the first polygons that do not intersect. Therefore, by using an expansion-merging and then equidistant shrinking method for each target land polygon, spatially adjacent scattered land can be merged into a unified target land outline, while restoring the actual land area. The land outline after unified buffering and merging is more continuous and regular, significantly reducing the workload of manual boundary trimming and effectively improving the efficiency of outline map generation.

[0163] The contour map generation method provided in this application can be applied to the generation of contour maps for any scene. The following example uses a residential area. Figure 16 The process of generating the outline map provided in this application is explained. At this time, the target land polygon is a residential land polygon, and the effective unit surface is a street block unit surface.

[0164] Step 1: Determine the effective surface of the multi-scale street block.

[0165] First, multi-source data preparation and coordinate system one can be carried out. The residential polygons, closed boundary line data and road line data of the target area are converted into coordinate system one. Then, the street unit surface can be dynamically constructed according to the scale.

[0166] For large-scale applications, micro-level street unit surfaces can be constructed using all road lines except internal roads in the road line data. For medium-scale applications, meso-level street unit surfaces can be constructed based on the remaining road line data by dynamically removing low-level road networks from the road line data. For small-scale applications, macro-level street unit surfaces can be constructed using only the outer closed boundaries of the road line data.

[0167] Afterwards, each street block layer can be generated, and a unique identifier, Area ID, can be set for each street block unit face.

[0168] Step 2: Perform spatial attribution mapping.

[0169] Among them, the topological classification of residential polygons can be determined.

[0170] If a residential polygon falls entirely within a single block unit face, it can be assigned a unique identifier, Area ID, which is the corresponding target unit face. If a residential polygon spans multiple block unit faces, the common road lines in the multiple block unit faces can be removed, and the multiple block unit faces involved can be merged into a joint block unit face. This joint block unit face can then be assigned a unique identifier, Area ID, which is the corresponding target unit face.

[0171] Step 3: Data grouping and high-concurrency computation.

[0172] The residential polygons can be divided into multiple groups according to Area ID, forming multiple street sandboxes, which are independent computing units corresponding to each target unit face. Then, multi-process scheduling can be performed to merge and process the residential polygons in each independent target unit.

[0173] For example, subprocess 1 processes street sandbox 1, subprocess N processes street sandbox N, subprocess X processes street sandbox X, and so on. Within each street sandbox, i.e., within the target cell surface of a street, operations such as positive buffer expansion, topological connectivity component joining, internal hole processing, geometric repair and simplification, negative buffer shrinkage, and narrow edge elimination can be performed on the polygons of each target settlement within it to obtain the settlement outline of each street sandbox. Therefore, the parallel computing method described above can significantly improve the efficiency of large-scale data processing.

[0174] Step 4: Space merging.

[0175] The residential outlines generated by each block sandbox can be spatially merged. For example, the residential outline 1 of block sandbox 1, the residential outline N of block sandbox N, and the residential outline X of block sandbox X can be spatially merged to obtain the complete residential outline map corresponding to the target area.

[0176] Understandably, the final generated complete outline map of the residential area has continuous boundaries and regular shape, which not only preserves the integrity of geographical entities but also eliminates redundant details. At the same time, the block unit surface constraints based on the road network effectively avoid topological conflicts where the land use outline crosses the road, and geometric repair and simplification ensure that global elements do not overlap, thus realizing the correctness of the topological relationship of massive data.

[0177] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0178] Based on the same inventive concept, this application also provides a contour map generation apparatus for implementing the contour map generation method described above. The solution provided by this apparatus is similar to the implementation described in the above method; therefore, the specific limitations of one or more contour map generation apparatus embodiments provided below can be found in the limitations of the contour map generation method described above, and will not be repeated here.

[0179] In one exemplary embodiment, such as Figure 17 As shown, a contour drawing generation apparatus 1700 is provided, comprising: a first determining module 1710, a second determining module 1720, a first generating module 1730, and a second generating module 1740, wherein:

[0180] The first determining module 1710 is used to determine a set of effective unit surfaces based on the closed boundary line data and the dividing line data of the target area. The set of effective unit surfaces includes multiple effective unit surfaces, and each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data.

[0181] The second determining module 1720 is used to determine the target unit face to which each target land polygon belongs based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face.

[0182] The first generation module 1730 is used to perform fusion processing on the target land polygons contained in each target unit surface to generate the target land outline of each target unit surface.

[0183] The second generation module 1740 is used to spatially merge the target land contours of each target unit surface to generate a complete target land contour map.

[0184] In one embodiment, the first determining module 1710 is specifically used for:

[0185] The closed boundary line data and the dividing line data are divided to obtain multiple line segments and multiple intersection points;

[0186] Construct a planar connected graph using the intersection points as nodes and the line segments as edges;

[0187] For each edge in the planar connected graph, the smallest closed loop containing the edge is determined as the valid closed loop corresponding to the edge;

[0188] The closed region enclosed by the effective closed loop is defined as the effective element surface, and all effective element surfaces constitute the effective element surface set.

[0189] In one embodiment, the second determining module 1720 is specifically used for:

[0190] For each target land polygon, the position coordinates of the target land polygon are matched with the position coordinates of each effective unit face;

[0191] If the geometric boundary of the target land polygon falls completely within the range of any valid unit surface, then the any valid unit surface is determined as the target unit surface of the target land polygon.

[0192] If the target land polygon intersects with multiple valid unit faces, the shared dividing line data among the multiple valid unit faces is removed, and the area after merging the multiple valid unit faces is determined as the target unit face of the target land polygon.

[0193] In one embodiment, the first generation module 1730 includes:

[0194] The first determining unit is used to process the map accuracy tolerance, map outline size threshold, scale parameters and dimension conversion coefficients to determine the first distance threshold.

[0195] The first generation unit is used to expand each of the target land polygons outward according to the first distance threshold to generate a first polygon, and merge multiple first polygons that have an intersection relationship to obtain a second polygon;

[0196] The second determining unit is used to shrink the joint polygon inward according to the first distance threshold to obtain the corresponding target land contour. The joint polygon includes the second polygon and the first polygon that does not intersect.

[0197] In one embodiment, the first generating unit is specifically used for:

[0198] For each target land polygon with internal holes, the target land polygon is expanded outward in the target direction corresponding to each boundary line according to the first distance threshold, and the internal holes are shrunken inward in the target direction corresponding to each boundary line according to the first distance threshold to generate a first polygon.

[0199] In one embodiment, the second determining unit is specifically used for:

[0200] If any of the joint polygons has an internal hole, the joint polygons are shrunk inward according to the first distance threshold, and the internal hole is expanded outward according to the first distance threshold to obtain the corresponding candidate land use outline.

[0201] If the candidate land use outline contains internal holes and the area of ​​the internal holes is less than a preset threshold, the internal holes are filled to obtain the corresponding target land use outline; or, if the candidate land use outline does not contain internal holes, or the area of ​​the internal holes is greater than or equal to the preset threshold, the candidate land use outline is determined as the target land use outline.

[0202] In one embodiment, the second determining unit is specifically used for:

[0203] Each joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding third polygon;

[0204] The third polygon is shrunk inward according to the second distance threshold to obtain the fourth polygon, where the second distance threshold is less than the first distance threshold.

[0205] The fourth polygon is expanded outward according to the second distance threshold to obtain the target land outline.

[0206] Each module in the aforementioned contour map generation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0207] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 18As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for generating a contour map. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0208] Those skilled in the art will understand that Figure 18 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0209] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0210] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0211] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0212] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0213] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0214] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0215] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for generating a contour map, characterized in that, The method includes: Based on the closed boundary line data and the dividing line data of the target area, a set of effective unit surfaces is determined. The set of effective unit surfaces includes multiple effective unit surfaces. Each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data. Based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face, the target unit face to which each target land polygon belongs is determined; Each target unit face contains a target land polygon that is fused to generate a target land outline for each target unit face. The target land contours of each target unit surface are spatially merged to generate a complete target land contour map.

2. The method according to claim 1, characterized in that, The step of determining the set of effective unit surfaces based on the closed boundary line data and segmentation line data of the target region includes: The closed boundary line data and the dividing line data are divided to obtain multiple line segments and multiple intersection points; Construct a planar connected graph using the intersection points as nodes and the line segments as edges; For each edge in the planar connected graph, the smallest closed loop containing the edge is determined as the valid closed loop corresponding to the edge; The closed region enclosed by the effective closed loop is defined as the effective element surface, and all effective element surfaces constitute the effective element surface set.

3. The method according to claim 1, characterized in that, The step of determining the target unit face to which each target land polygon belongs based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face includes: For each target land polygon, the position coordinates of the target land polygon are matched with the position coordinates of each effective unit face; If the geometric boundary of the target land polygon falls completely within the range of any valid unit surface, then the any valid unit surface is determined as the target unit surface of the target land polygon. If the target land polygon intersects with multiple valid unit faces, the shared dividing line data among the multiple valid unit faces is removed, and the area after merging the multiple valid unit faces is determined as the target unit face of the target land polygon.

4. The method according to claim 1, characterized in that, The step of fusing the target land polygons contained in each target unit face to generate the target land outline of each target unit face includes: The map accuracy tolerance, map outline size threshold, scale parameters, and dimension conversion coefficients are processed to determine the first distance threshold; Each of the target land polygons is expanded outward according to the first distance threshold to generate a first polygon, and multiple first polygons that have an intersection relationship are merged to obtain a second polygon; The joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding target land use outline. The joint polygon includes the second polygon and the first polygon that does not intersect.

5. The method according to claim 4, characterized in that, The step of expanding each of the target land polygons outward according to the first distance threshold to generate a first polygon includes: For each target land polygon with internal holes, the target land polygon is expanded outward in the target direction corresponding to each boundary line according to the first distance threshold, and the internal holes are shrunken inward in the target direction corresponding to each boundary line according to the first distance threshold to generate a first polygon.

6. The method according to claim 4, characterized in that, The step of shrinking the joint polygon inward according to the first distance threshold to obtain the corresponding target land use outline includes: If any of the joint polygons has an internal hole, the joint polygons are shrunk inward according to the first distance threshold, and the internal hole is expanded outward according to the first distance threshold to obtain the corresponding candidate land use outline. If the candidate land use outline contains internal holes and the area of ​​the internal holes is less than a preset threshold, the internal holes are filled to obtain the corresponding target land use outline; or, if the candidate land use outline does not contain internal holes, or the area of ​​the internal holes is greater than or equal to the preset threshold, the candidate land use outline is determined as the target land use outline.

7. The method according to claim 4, characterized in that, The step of shrinking the joint polygon inward according to the first distance threshold to obtain the corresponding target land use outline includes: Each joint polygon is shrunk inward according to the first distance threshold to obtain the corresponding third polygon; The third polygon is shrunk inward according to the second distance threshold to obtain the fourth polygon, where the second distance threshold is less than the first distance threshold. The fourth polygon is expanded outward according to the second distance threshold to obtain the target land outline.

8. An apparatus for generating a contour map, characterized in that, The device includes: The first determining module is used to determine a set of effective unit surfaces based on the closed boundary line data and the dividing line data of the target area. The set of effective unit surfaces includes multiple effective unit surfaces, and each effective unit surface is the smallest closed region formed by the dividing line data and / or the closed boundary line data. The second determining module is used to determine the target unit face to which each target land polygon belongs based on the position coordinates of the target land polygon in the target area and the position coordinates of each effective unit face; The first generation module is used to merge the target land polygons contained in each target unit face to generate the target land outline of each target unit face. The second generation module is used to spatially merge the target land contours of each target unit surface to generate a complete target land contour map.

9. 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 steps of the method according to any one of claims 1 to 7.

10. 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 steps of the method according to any one of claims 1 to 7.

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