A method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes

Abstract

This invention provides a method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes, relating to the field of symbolization of basic geographic elements in cadastral surveys. This method includes establishing a symbol library for basic geographic elements in cadastral surveys and establishing a correspondence between symbol codes and different symbol styles; inputting and identifying the vector layers of basic geographic elements to be symbolized; obtaining the symbol codes and corresponding symbol categories within the vector layers to be symbolized; if the symbol category is a template symbol type, rendering is performed according to the symbol styles configured in the symbol template file; if the symbol category is a custom symbol type, the spatial graphics and self-attribute values ​​of the element are read, and spatial transformation processing is performed on the element graphics. By combining static rendering and dynamic drawing, this method solves the problem that existing technologies cannot meet the personalized expression needs of complex basic geographic elements.

Description

Technical Field

[0001] This invention relates to the field of geographic element symbolization technology in cadastral surveys, specifically a method for rendering basic geographic element symbols that takes into account both cadastral semantics and attributes. Background Technology

[0002] Map symbols are abstract representations of real-world geographic features and are an important information carrier for GIS visualization. The design and rendering of these symbols are crucial for the accurate and realistic representation of spatial points, lines, and areas in vector data, directly impacting people's understanding of the geographic world. A map symbol library is a collection of map symbols, typically stored in a computer as a database.

[0003] Standardized and accurate symbolic rendering of cadastral survey results is of great value and significance for subsequent work. However, common GIS platform software, such as ArcGIS, SuperMap, and MapGIS, lacks built-in symbol libraries for cadastral survey-related features, failing to meet the representation needs of complex geographic elements, such as steps with layer attributes, city walls with width attributes, and rivers with direction attributes. Because the symbolic effects of these features change depending on their attributes, they cannot be pre-designed and stored in a symbol library; they must be dynamically rendered by custom functions.

[0004] Therefore, a method for rendering basic geographic element symbols is provided. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a basic geographic element symbol rendering method that takes into account cadastral semantics and attributes, solving the problem that existing technologies cannot meet the expression needs of complex geographic elements.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] Firstly, a method for rendering basic geographic element symbols that takes into account both cadastral semantics and attributes is provided, the method comprising:

[0010] Establish a symbol library for basic geographic elements in cadastral surveys, and establish a correspondence between symbol codes and different symbol styles;

[0011] Input and identify the basic geographic feature vector layers that need to be symbolized;

[0012] Obtain the symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized. The symbol categories include template symbol types and custom symbol types.

[0013] If the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the layer symbol dictionary; symbolization rendering is performed according to the determined style;

[0014] If the symbol category is a custom symbol type, the feature graphic and the feature's self-attribute values ​​are read, and the feature graphic is spatially transformed based on the attribute values; finally, dynamic symbolization rendering is performed.

[0015] Preferably, the symbol library for basic geographic elements in cadastral surveys includes three symbol styles: point symbols, line symbols, and area symbols.

[0016] Preferably, the determination of the symbol code specifically includes:

[0017] A symbol index table is created in the local database file. The symbol index table contains layer names, feature codes, symbol codes, and symbol categories. The corresponding symbol codes are found based on the layer names and feature codes in the symbol index table. The corresponding symbol styles are retrieved from the symbol library of basic geographic features for cadastral survey based on the symbol codes.

[0018] Preferably, obtaining the symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized specifically includes:

[0019] Based on the layer name and feature code of the input basic geographic feature vector layer, determine the symbol codes corresponding to all vector layers that need to be symbolized, and look up the corresponding symbol category in the symbol index table according to the symbol codes.

[0020] Preferably, if the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the layer symbol dictionary; symbolization rendering is performed according to the determined style, specifically including:

[0021] The symbol index table also contains symbol identifiers. The symbol identifier is found in the symbol index table by the symbol code. The value of the symbol identifier field is separated by a comma, which respectively represents the symbol code of the dotted symbol and the line symbol to be superimposed.

[0022] The symbol is rendered at the original coordinates of the ground feature based on the obtained symbol code; if the symbol identifier field is not empty, the corresponding symbol style is searched in the classification symbol table according to the symbol order and the template symbolization program is called for rendering.

[0023] Preferably, if the symbol category is a custom symbol type, then the spatial graphic of the feature and the self-attribute values ​​of the feature are read, and the spatial transformation processing of the feature graphic is performed according to the attribute values; finally, dynamic symbolization rendering is performed, specifically including:

[0024] Read the corresponding attribute values ​​from the feature attribute table based on different feature codes and specified attribute fields;

[0025] Based on two rows of basically symmetrical points, spatial transformation is performed according to the element's self-attribute values ​​and the shape and structure of the spatial graphic.

[0026] If the symbol being rendered is a dot-shaped symbol, and the coordinates of the positioning point where the symbol is drawn are the coordinates of the corresponding entity, then the symbol will be rendered according to its color, size, and offset information.

[0027] If the symbol being rendered is a line, the appropriate rendering method is selected based on the characteristics of the line symbol; specifically, this includes pure function drawing (creating a rendering function for each type of symbol), vertically stacked primitives (dividing the symbol vertically into symbol units and drawing them sequentially according to the coordinate points of the axis feature), and horizontally cyclically configured primitives (dividing the symbol horizontally into cyclic units and drawing them cyclically according to the axis).

[0028] If the rendered object is a surface symbol, which is a superposition of point symbols and / or line symbols, then the rendering will follow the rendering method for point symbols and / or line symbols.

[0029] In a second aspect, a computer-readable storage medium is provided for storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods described.

[0030] Thirdly, a computing device is provided, comprising:

[0031] One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods described.

[0032] (III) Beneficial Effects

[0033] This invention provides a method for rendering basic geographic element symbols that considers cadastral semantics and attributes. First, a basic geographic element symbol library for cadastral surveys is established. Second, based on the attributes of the land features, the elements to be symbolized are divided into template symbol types and custom types, representing symbols directly obtained from the symbol library based on symbol codes and symbols dynamically rendered based on the element's own attribute values, respectively. This technology combines static and dynamic rendering to achieve the symbolic representation of complex land features, possesses a certain degree of scalability, and can accurately and vividly represent the land feature characteristics of cadastral survey results, including external contours, compositional features, and colors, thus meeting the visualization requirements of various cadastral survey results. Attached Figure Description

[0034] Figure 1 This is a flowchart of the method of the present invention;

[0035] Figure 2 This is a diagram of the symbol editing interface for "damaging a house" in an embodiment of the present invention;

[0036] Figure 3 This is a rendering diagram of the "destroy a house" symbol of the template symbol type in an embodiment of the present invention;

[0037] Figure 4 This is a rendering diagram of the "grassland" symbol of the template symbol type in an embodiment of the present invention;

[0038] Figure 5 This is a rendering diagram of a custom type "step" symbol in an embodiment of the present invention;

[0039] Figure 6 This is a rendering diagram of a custom type "wall" symbol in an embodiment of the present invention. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] Example

[0042] like Figure 1 As shown, a method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes is presented. This method includes:

[0043] Establish a symbol library for basic geographic elements in cadastral surveys, and establish a correspondence between symbol codes and different symbol styles;

[0044] Input and identify the basic geographic feature vector layers that need to be symbolized;

[0045] Obtain the symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized. The symbol categories include template symbol types and custom symbol types.

[0046] If the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the layer symbol dictionary; symbolization rendering is performed according to the determined style;

[0047] If the symbol category is a custom symbol type, the feature graphic and the feature's self-attribute values ​​are read, and the feature graphic is spatially transformed based on the attribute values; finally, dynamic symbolization rendering is performed.

[0048] Furthermore, the symbol library for basic geographic elements in cadastral surveys includes three symbol styles: point symbols, line symbols, and area symbols. Point symbols are created using FontCreator font editing software, and the resulting font file is imported into ArcGIS StyleManager. Line and area symbols are created using the editing functions of StyleManager. In actual creation, line symbols are mainly composed of several simple line or point symbols with single characteristics superimposed. Relatively complex line symbols can be created by setting line width, offset values, and regularly repeating symbol spacing. Area symbols are mainly composed of point symbols, line symbols, fill colors, and other elements superimposed. Area fill includes five methods: single-color fill, gradient fill, cartographic line fill, point symbol fill, and image fill.

[0049] Furthermore, the determination of the symbol code specifically includes:

[0050] A symbol index table is created in the local database file. The symbol index table contains fields such as layer name, feature code, feature name, feature type, symbol code, symbol category, and symbol identifier. The corresponding symbol code is found based on the layer name and feature code in the symbol index table. The corresponding symbol style is retrieved from the symbol library of basic geographic features for cadastral survey based on the symbol code.

[0051] Furthermore, the acquisition of symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized specifically includes:

[0052] Based on the layer name and feature code of the input basic geographic feature vector layer, determine the symbol codes corresponding to all vector layers that need to be symbolized, and look up the corresponding symbol category in the symbol index table according to the symbol codes.

[0053] Furthermore, if the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the layer symbol dictionary; symbolization rendering is performed according to the determined style, specifically including:

[0054] The symbol index table also contains symbol identifiers. The symbol identifier field (which indicates that the rendering of the symbol requires multiple layers of filling) is searched in the symbol index table by the symbol code. The values ​​of the symbol identifier field are separated by commas, representing the symbol codes of the dotted symbols and line symbols to be superimposed, respectively.

[0055] The symbol codes are used to perform symbolic rendering at the original coordinates of the ground features; if the symbol identifier field is not empty, the corresponding symbol style is searched in the classification symbol table according to the symbol order and the template symbolization program is called for rendering.

[0056] Furthermore, if the symbol category is a custom symbol type, then the feature graphic and its self-attribute values ​​are read, and spatial transformation processing is performed on the feature graphic based on the attribute values; finally, dynamic symbolization rendering is performed, specifically including:

[0057] Read the corresponding attribute values ​​from the feature attribute table based on different feature codes and specified attribute fields;

[0058] Based on two rows of basically symmetrical points, spatial transformation is performed according to the element's self-attribute values ​​and the shape and structure of the spatial graphic.

[0059] If the symbol being rendered is a dot-shaped symbol, and the coordinates of the positioning point where the symbol is drawn are the coordinates of the corresponding entity, then the symbol will be rendered according to its color, size, and offset information.

[0060] If the symbol to be rendered is a line, then the appropriate rendering method is selected based on the characteristics of the line symbol.

[0061] If the rendered object is a surface symbol, which is a superposition of point symbols and / or line symbols, then the rendering will follow the rendering method for point symbols and / or line symbols.

[0062] Specifically, in step one, a symbol library file named GTIS.style is created for basic geographic elements in cadastral surveys. This symbol library includes three symbol styles: point symbols, line symbols, and area symbols. For example, the symbol editing interface for the "damaged houses" element is shown below. Figure 2As shown, after the symbol editing is completed, a symbol index table is established to identify the correspondence between symbol codes and symbol styles, and a categorized symbol table is created in the Access database; this step has been described in detail above and will not be repeated here.

[0063] Step 2: Input and identify the basic geographic feature vector layer that needs to be symbolized; in this case, the layer selected for symbolization is XZJMD.

[0064] Step 3: Obtain the symbol codes and corresponding symbol categories within the layer; taking "damaged house" and "steps" as examples, the symbol code for the "damaged house" element is "1310700", and its symbol category is template symbol type; the symbol code for the "steps" element is "1324001", and its symbol category is custom type.

[0065] Step four: As we know from step three, the symbol category for the "damaged house" element is the template symbol type. Furthermore, the rendering process for this type of symbol includes the following steps:

[0066] Please see Figure 3 ,in, Figure 3 (a) Figure 3 (b) shows a schematic diagram of the symbols used for superposition. Figure 3 (c) is a schematic diagram of the final symbolic effect of "destroying a house";

[0067] Step S1: Search for the symbol identifier field value in the category symbol table using the symbol code "1310700"; the value of the symbol identifier field for this symbol code is "1310701, 1310702", indicating that the symbol styles to be superimposed to generate this symbol are as follows: Figure 3 (a) Figure 3 As shown in (b);

[0068] Step S2: Based on the symbol codes "1310701,1310702" and symbol styles obtained in the previous step, perform symbolic rendering on the original coordinates of the ground features;

[0069] Step 5: If the symbolic element is "steps," the symbol category is a custom type. For example... Figure 5 As shown in (a), this is the initial captured image of the steps before symbolization. Further, the rendering process for this symbol includes the following steps:

[0070] Step W1: Read the feature layer number attribute value as "20" according to the symbol code, which means that the step has 20 layers;

[0071] Step W2: with Figure 5In (a), the two symmetrical lines are used as the positioning basis. Spatial transformation is performed based on the element's self-attribute value and the shape and structure of the spatial graphic. First, the two parallel line segments are equally divided according to the step length and layer number attribute values. Then, the coordinate pairs of all the dividing points are calculated based on the original graphic coordinates (each pair represents the endpoint coordinates of the drawn line segment). The drawing program is called to draw the parallel line segments based on the coordinate values.

[0072] Step W3: Based on the characteristics of the rendered graphics, the "steps" element in this case is rendered using a horizontal loop primitive method. First, the symbol is horizontally divided into individual symbol units (in this case, line segments with coordinate value pairs). Then, the program is called to draw them in a loop according to the coordinate values. The final symbol effect is as follows. Figure 5 As shown in (b).

[0073] Figure 4 and Figure 6 The images show before and after rendering of the "Grassland" element (template symbol type) and the "Fence" element (custom type). The rendering process is similar to the process described above and will not be repeated here. Figure 4 In the diagrams (a) and (b), the symbols for superposition are shown. Figure 4 Image (c) is a schematic diagram of the final symbolic effect of "grassland"; in which, Figure 6 (a) represents the initial graphic schematic diagram without symbolic rendering; Figure 6 (b) represents a schematic diagram of the effect after symbolic rendering according to the present invention.

[0074] Embodiments of this application may be provided as methods or computer program products. Therefore, this application may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application may be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0075] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0076] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0077] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes, characterized in that, include: Establish a symbol library for basic geographic elements in cadastral surveys, and establish a correspondence between symbol codes and different symbol styles; Input and identify the basic geographic feature vector layers that need to be symbolized; Obtain the symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized. The symbol categories include template symbol types and custom symbol types. If the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the symbol dictionary of the vector layer; symbolization rendering is then performed according to the determined style. If the symbol category is a custom symbol type, the spatial graphic of the feature and the self-attribute value of the feature are read, and the spatial transformation of the feature graphic is performed according to the attribute value; finally, the custom program algorithm is called to perform dynamic symbolization rendering according to the determined style. The determination of the symbol code specifically includes: A symbol index table is established in the local database file. The symbol index table contains layer name, feature code, symbol code and symbol category. The corresponding symbol code is found according to the layer name and feature code in the symbol index table. The corresponding symbol style is retrieved from the symbol library of basic geographic elements for cadastral survey according to the symbol code. The process of obtaining the symbol codes and corresponding symbol categories within the basic geographic feature vector layer that needs to be symbolized specifically includes: Based on the layer name and feature code of the input basic geographic feature vector layer, determine the symbol codes corresponding to all vector layers that need to be symbolized, and look up the corresponding symbol category in the symbol index table according to the symbol codes.

2. The method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes according to claim 1, characterized in that, The symbol library for basic geographic elements in cadastral surveys includes three symbol styles: point symbols, line symbols, and area symbols.

3. The method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes according to claim 1, characterized in that, If the symbol category is a template symbol type, then the corresponding symbol style is read from the symbol library file according to the symbol code, and the symbol code and corresponding symbol style are added to the layer symbol dictionary; symbolization rendering is performed according to the determined style, specifically including: The symbol index table also contains symbol identifiers. The symbol identifier is found in the symbol index table by the symbol code. The value of the symbol identifier field is separated by a comma, which respectively represents the symbol code of the dotted symbol and the line symbol to be superimposed. The symbol is rendered at the original coordinates of the ground feature based on the obtained symbol code; if the symbol identifier field is not empty, the corresponding symbol style is searched in the classification symbol table according to the symbol order and the template symbolization program is called for rendering.

4. The method for rendering basic geographic element symbols that takes into account cadastral semantics and attributes according to claim 1, characterized in that, If the symbol category is a custom symbol type, then the spatial graphic of the feature and the self-attribute value of the feature are read, and the spatial transformation processing of the feature graphic is performed according to the attribute value. Finally, dynamic symbolic rendering is performed, specifically including: Read the corresponding attribute values ​​from the feature attribute table based on different feature codes and specified attribute fields; Based on two rows of basically symmetrical points, spatial transformation is performed according to the element's self-attribute values ​​and the shape and structure of the spatial graphic. If the symbol being rendered is a dot-shaped symbol, and the coordinates of the positioning point where the symbol is drawn are the coordinates of the corresponding entity, then the symbol will be rendered according to its color, size, and offset information. If the element to be rendered is a line symbol, the corresponding rendering method is selected based on the characteristics of the line symbol; specifically, this includes pure function drawing, vertically stacked primitives, and horizontally cyclically configured primitives. If the rendered object is a surface symbol, which is a superposition of point symbols and / or line symbols, then the rendering will follow the rendering method for point symbols and / or line symbols.

5. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1-4.

6. A computing device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1-4.

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