CN110489499A - A kind of on-line intelligence special map plotting method - Google Patents

Abstract

The present invention provides a kind of on-line intelligence special map plotting method, including building thematic maps template, including the general template for spatial analysis result and for the synthesis template of thematic charting achievement；It is required according to making thematic map, building meets the base map pattern file of mapbox style standards；On-line intelligence thematic charting system framework is constructed, supports to load whole picture thematic maps by on-line intelligence special map plotting system；The process of load thematic maps is divided into two parts, a part is the configured base map file of load, and another part is load spatial analysis special layer data generated, according to pattern prepared in thematic maps template, special layer is successively added, whole picture thematic maps is formed.The present invention proposes that the building of template is advantageously implemented the linking from spatial analysis to thematic charting function；Data organization frame is provided for a variety of thematic representation methods when constructing thematic maps template, convenient for supporting user to the editor of entire thematic maps.

Description

An Online Intelligent Thematic Map Compilation Method

technical field

The invention relates to the technical field of computer thematic map compilation, in particular to an online intelligent thematic map compilation method.

Background technique

Thematic map, also known as special map, is to highlight and perfectly represent one or several elements related to the theme on the geographic base map according to the requirements of the map theme, so that the content of the map is thematic and expressed in different forms , purpose-specific maps. The content of the thematic map consists of two parts: ①Thematic content. Natural or socio-economic phenomena and their associated characteristics highlighted on the map. ②Geographic basis. Common map content used to indicate the spatial location and geographical background of thematic elements mainly includes graticules, water systems, boundaries, and residential areas. With the application of geographic information system more and more widely, there are more and more fields that require thematic map compilation, and the demand for thematic mapping in various fields is becoming more and more specialized and refined. Thematic mapping needs to be combined with specific spatial analysis. The results are combined. At the same time, thematic maps need richer expression methods and forms, and more professional references are also required in the configuration of styles. Under this background, a more professional method that can be compared with various thematic analysis results is proposed. Combined thematic mapping methods are particularly important.

At present, there are some methods for thematic map compilation, but these methods generally have the following types of problems: First, thematic maps lack suitable mapping templates, and cannot directly convert the spatial analysis results of specific fields into thematic ones with more reasonable expressions Second, the construction of the thematic map compilation function system is not perfect, and it is difficult to coordinate the functions of importing and exporting the whole map of thematic maps, editing base maps and thematic layers, switching representation methods, and interacting with thematic maps ; Third, there is a lack of suggestions on more mature thematic map compilation methods. For the representation of attribute elements, the style selection of thematic layers, etc., there is a lack of symbols library, color library, font library and other achievements derived from existing cartographic results.

With regard to online thematic mapping, the relevant background technologies are developing quite rapidly. In terms of spatial data transmission, vector slice technology is more and more widely used. Vector slice technology preprocesses vector data into "tiles" that are close to squares. When calling data on the web page, only the current screen range and zoom level can be called At the same time, compared with raster slices, vector slices can be more flexibly and dynamically combined with style files, thus increasing the real-time and flexibility of rendering ; In terms of map rendering, the Web Graphics Library (WebGL for short) provides vector graphics rendering technology. Drawing tools such as mapbox, openlayers, and mapnik form a personalized interface for front-end vector map rendering and editing through the use of WebGL technology , which is easier for users to use; at the level of front-end framework construction, Vue, React, Angular and other web architecture technologies support web page modules driven by data, increasing the flexibility of web page development.

Contents of the invention

The present invention mainly solves some problems existing in some existing thematic map compilation methods, and constructs a relatively complete thematic map compilation system and system.

The technical solution of the present invention provides an online intelligent thematic map compilation method, comprising the following steps:

Step 1. Build thematic map templates, including general templates for spatial analysis results and comprehensive templates for thematic mapping results;

Step 2, according to the requirements of thematic map drawing, construct a base map style file that conforms to the mapbox style standard;

Step 3: Build the framework of the online intelligent thematic mapping system, which supports loading the entire thematic map through the online intelligent thematic map compilation system; the process of loading the thematic map is divided into two parts, one is to load the configured base map file, and the other is to load the The thematic layer data generated by spatial analysis, according to the style specified in the thematic map template, add thematic layers in sequence to form the entire thematic map.

Moreover, in step 1, the thematic map template contains basic map information and thematic layer information, and thematic layer information contains basic layer information and layer style information. Basic layer information includes layer id, name, and layer Type, layer style information includes layer visibility, layer representation method and layer style specification.

Moreover, in step 2, constructing the basemap style file includes the following sub-steps:

Step 2.1, configure the basemap data source, publish the basemap data source in the corresponding server and obtain its service address;

Step 2.2, configure the map symbol library data source, the symbol library data source conforms to the sprite format specified by Mapbox;

Step 2.3, configure the map font library data source, the font library data source conforms to the font slice format specified by Mapbox;

Step 2.4, configure the styled base map layer, and integrate the data sources in steps 2.1 to 2.3 to form a complete map style file.

Moreover, in steps 2.2 to 2.4, the style configuration of map symbols, fonts and basemaps can use the existing thematic map drawing results to provide users with style configuration reference.

Moreover, the page organization of the online intelligent thematic mapping system framework in step 3 includes five parts including page style, component, configuration, page, and tool;

The page style part specifies the style of each display module in the page;

Components include four parts: ribbon bar, data item, layer item and layer data item in the page, and these four parts are responsible for interacting with data in the page;

The configuration part includes service address, service acquisition command splicing and service acquisition interface. These parts cooperate with each other to form commands for adding, deleting, checking and modifying operations from the server side;

The page part includes the data list, layer edit list, layer list and map display part, which form the basis of the entire previous page display;

The tool part includes grading tools, color configuration tools and map editing tools, among which the grading tools are used to classify thematic data; the color configuration tool uses a color interpolation algorithm, which can convert the discrete color bands in the color library into continuous ones Grading and classification of colors to suit users for more levels of thematic coloring; map editing tools; use the tool interface in mapboxgl to edit map layer styles and layer organization edits.

The above intelligent thematic map compilation method provides a basic framework for spatial analysis-based mapping and user-defined mapping through the configuration of general templates and comprehensive templates, and provides users with various editing options according to the template structure. In addition, this method also fully absorbs the existing excellent thematic mapping achievements, and constructs mapping resources such as symbol library, color library, and template library.

Therefore, the present invention has the following advantages: 1. The construction of the template is conducive to docking with the spatial analysis module, realizing the connection from spatial analysis to thematic mapping; 2. The present invention provides various thematic representation methods when constructing thematic map templates. Data organization framework, so users can edit the entire thematic map by editing a module in the thematic map template, and can refer to existing cartographic results during the editing process; 3. The invention uses the front-end mapping method library provided by mapbox As the core tool library, mapboxgl provides a whole set of methods for map rendering, editing, interaction, and transmission, and builds a relatively complete thematic map compilation system.

Description of drawings

FIG. 1 is a system structure diagram of an embodiment of the present invention.

FIG. 2 is a structural diagram of a thematic map template according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of the page organization of the online thematic map compilation system according to the embodiment of the present invention.

Detailed ways

In order to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The structure diagram of the system used in the embodiment of the present invention is shown in FIG. 1 . A thematic map is organized in the format of a map file, which consists of two parts: a map template and thematic data. Among them, the map template includes the basemap style file used by this type of thematic map (including basemap source data information, symbol and font information, and basemap style information), organization information of thematic layers, and style information of thematic layers. Basemap source data information may include basemap slice addresses, and symbol and font information may include symbols and font addresses. The operations on different parts of the map file form different functions in the system: basemap rendering is realized by loading the basemap file; editing of thematic layer style is accomplished by modifying thematic layer style information in the map template; By modifying the thematic layer organization information in the map template, functions such as adding, deleting, hiding, and order adjustment of thematic layers can be performed; and when the driving data of the thematic layer is combined with the map template, the mapboxgl can be used to The interface provided implements the rendering function of thematic layers.

In this system, two different thematic map compilation requirements are met: one is the cartographic function combined with the spatial analysis results of specific themes, which can provide different cartographic templates for spatial analysis models of different themes. The combination of the results forms a map file, and then renders the entire thematic map through the analysis of the map file, so as to realize the "seamless connection" from spatial analysis to thematic mapping; the second is to realize the "from scratch" mapping function, namely Support users to choose drawing templates, spatial data, attribute data, etc. for personalized drawing. Two different mapping requirements require the system to provide different mapping templates, while providing comprehensive thematic map editing and interactive functions.

The thematic map preparation method provided by the present invention realizes the connection between thematic cartography and the spatial analysis model by constructing thematic map templates; through the vector map design tool provided by mapbox, functional modules such as map loading, editing, finishing, interaction, and output are realized; through Extract existing thematic map drawing results and build a thematic map style library. This method realizes the docking of spatial analysis and thematic mapping functions, provides users with a more professional thematic map style reference, and builds a set of relatively complete and lightweight online intelligent thematic map compilation system.

An online intelligent thematic map preparation method provided in the embodiment includes the following steps:

Step 1. Build a thematic map template: build a cartographic template for a specific thematic spatial analysis model (hereinafter referred to as a general template) and a cartographic template for existing thematic map results (hereinafter referred to as a comprehensive template). Map data source, thematic layer organization, thematic layer basic information, thematic layer data source, thematic layer style and other information are specified.

Thematic templates are divided into general templates and comprehensive templates, corresponding to spatial analysis models and existing thematic mapping results respectively. The overall structure of the thematic map template is shown in Figure 2, which includes two parts: basic map information and thematic layer information. The basic information of the map includes the map's Id, author, name, update date and basemap file, where the basemap file can be a json (JavaScript Object Notation, JavaScript object notation, is a lightweight data exchange format) object, It can also be the link address corresponding to the json file. Thematic layer information includes two parts: layer basic information and layer style information. Layer basic information includes layer id, name, and layer type. The layer id is the basic identifier for identifying a layer. It is necessary to ensure that each The id value of each layer is unique, and the layer name is the information used for interface display. The layer types are divided into four types: "point", "line", "polygon" and "image", respectively representing points, lines, areas and A layer of raster image type. Layer style information includes layer visibility (that is, display or not), layer representation methods, and specific style regulations. Among them, the representation methods of point layers include fixed point symbol method, heat map method, point number method and positioning chart method , the representation method of a linear layer is the linear symbol method, the representation method of an area layer includes the hierarchical statistical chart method and the zonal statistical chart method, and the layer style specification describes the color, symbol, size and other style information of the layer.

Among them, the thematic layer mainly has three types of thematic layers according to the different types of geographic elements: point, line, and area. Each type of layer has a different representation method, and each type of representation method corresponds to a different template organization method. Therefore, constructing a thematic map template is to abstract the thematic map into a set of mapping rules described by json objects according to the organizational rules described in Figure 2. In specific implementation, the thematic map template can directly use the existing thematic mapping results.

Step 2, construct basemap file: according to the requirements of thematic map drawing, construct a basemap style file conforming to the mapbox style standard.

The basemap file is essentially a style file in json format that conforms to the mapbox style standard. In this file, the basemap information, basemap data source, map style data source (including symbols and fonts), layer organization, layer style, etc. The information is specified, mapboxgl, a tool for map rendering and editing in mapbox, can directly load the basemap file and render the basemap on the front end.

In step 2, building the basemap style file includes the following sub-steps:

Step 2.1, configure the basemap data source, publish the basemap data source in the corresponding server and obtain its service address.

The file format of the basemap data source is generally a vector tile, and the vector tile service is generated by the map service tool geoserver, and the vector tile extension module of geoserver provides the function of generating a vector tile service. Upload the shp (shapefile, the map layer file format developed by ESRI) file required for basemap rendering in geoserver and publish the layer, then you can get the corresponding vector slice service address;

In the mapbox style standard, the format of the basemap data source can be vector slices, rasters, digital elevation models (DEM), geojson (a JSON-compliant format that encodes various geographic data structures), pictures , Video six. Regardless of the data source, it must be specified in the style file through the server address of the data source.

Step 2.2, configure the map symbol library: configure the map symbol library data source, the symbol library data source conforms to the sprite format specified by Mapbox.

The data source form of the map symbol library used in the Mapbox style file is sprite, which is a form of centralized storage of all map symbols. The sprite consists of two parts, one is a png image spliced by all map symbols, and the other is It is a json file that describes all symbol names and location information in png images. Mapbox builds sprites to reduce communication frequency and improve system efficiency. Use the tool spritezero-cli provided by mapbox to convert multiple svg (Scalable Vector Graphics, scalable vector graphics, a graphic format for describing two-dimensional vector graphics) symbol files into sprite files.

Before configuring the map symbol library, you can first extract the svg files of commonly used thematic map symbols through the existing thematic mapping results, and unify the sizes of these symbols. After that, use the spritezero-cli tool to convert the svg symbol file set into a sprite file. After the generation is complete, place the sprite file on the server, and specify the symbol library of the thematic map by referring to the address of the server in the style file.

Step 2.3, configure the map font library: configure the map font library data source, and the font library data source conforms to the font slice format specified by Mapbox.

The font library file used in the Mapbox style file is a font slice, which is similar to the format of a vector slice. It divides a font into several pbf (protocol buffer, an independent data exchange of Google) according to a certain number of characters. format) format file. In this step, use the node-fontnik tool provided by mapbox to convert the font file in ttf or otf format of the font to be used into a font slice

The source file required to configure the font library is the ttf or otf format file of the required font. Through the node-fontnik tool, the font source file is converted into a font slice file. The font slice file is also placed on the server and referenced by the style file.

Step 2.4, configure the basemap layer organization and style, and build a complete style file: use mapbox studio or other tools to configure the styled basemap layer, and integrate the data sources in steps 2.1 to 2.3 to form a complete map style file.

This step builds the layer organization and layer style of the basemap file. Among them, the style of the base map layer can use the existing cartographic achievements. By referring to the existing cartographic achievements, map style resources such as color library and symbol library can be constructed, and based on these style resources, the thematic map style library can be constructed.

The Mapbox style specification stipulates a variety of map style expression methods, and you can refer to the regulations for style configuration. Since it is cumbersome to directly write the JSON format code of the style file, you can use some style file generation tools for "what you see is what you get" style configuration, such as mapbox studio, maputnik, ArcGIS Vector TileStyle Editor, etc.

The configuration of the basemap data source and map resources in the style file has been introduced in steps 2.1 to 2.3. For the configuration of layer style and layer organization, tools such as mapbox studio, maputnik, and ArcGIS VectorTile Style Editor can be used. Taking mapbox studio as an example, first upload the data required for mapping to the workspace, then use these data for mapping, and configure the map as the required style. After the configuration is completed, the configured map style will be published through the "publish" function. Published in the workspace. After publishing, you can download the style file locally to get the required layer organization and style code.

Integrate each data source and match the style layer with the basemap data source layer. The addresses of the base map data source, symbol library data source, and font library data source described in steps 2.1 to 2.3 are respectively specified in the "source", "sprites" and "glyphs" fields in the style file. At the same time, the layer name specified in the "source-layer" field of each layer in the layers field must be consistent with the name of each layer configured in geoserver, otherwise the style of each layer cannot match the corresponding The data source is matched, and the map rendering cannot be completed.

The configuration method of the basemap file described in the above step 2 is aimed at the most common situation in the configuration of the basemap file with vector slices as the data source, because the configuration process is relatively complicated, and the present invention provides it for those skilled in the art to implement refer to. In addition to the configured vector slices, the basemap data source of the thematic map can also be raster slices, raster images, DEM data, etc. The data sources in these other cases can be obtained directly without separate configuration of the data source. The mapbox style specification also provides corresponding layer style expressions for these data sources.

Step 3: Construct an online thematic map compilation system by module: construct an online intelligent thematic mapping system framework to realize functional modules such as model loading, map loading, map editing, map interaction, and map export.

Various functional modules can be built through the web page, including modules such as template selection, map rendering, layer editing, map interaction, and map export. The core functions of the web page are implemented using the interfaces in the mapbox-gl.js library.

In the embodiment, the main functional modules implemented include a map loading module, a map editing module, a map interaction module, a map transmission (export) module, and the like. The page organization of the online thematic map compilation system is shown in Figure 3. The entire page resource includes five parts: page style, component, configuration, page, and tool: the page style part specifies the style of each display module in the page; the component includes the color band in the page There are four parts: bar, data item, layer item and layer data item. These four parts are responsible for interacting with data on the page; the configuration part includes service address, service acquisition command splicing and service acquisition interface. Parts cooperate with each other to form commands for adding, deleting, checking, modifying and other operations from the server side; the page part includes data list, layer edit list, layer list and map display part, these parts form the basis of the entire front page display ;The tool part mainly includes grading tools, color configuration tools and map editing tools. Among them, the grading tools include several common data grading methods for grading and classifying thematic data. The color configuration tool uses a color interpolation algorithm, which can Convert the discrete color bands in the color library into continuous graded and classified colors to suit users for more levels of thematic coloring. The map editing tool mainly uses the tool interface in mapboxgl to edit the layer style and layer organization of the map and so on. The function of each module is completed through an independent file to increase the reusability of these modules.

During specific implementation, the front-end framework of the mapping system is organized according to the structure in Figure 3, and the modules are loosely coupled to ensure the reusability of the modules.

Taking the blind area analysis model of park green space supply within Putuo District of Shanghai as an example, the following introduces the implementation method of the entire online intelligent thematic map compilation:

1. Build a general template for the map. First specify the basic information such as map id, name, author, and update date (the base map address information will be filled in after the subsequent steps are configured). Secondly, configure the thematic layer organization and style information. The map template of the park green space supply blind area analysis model consists of 4 thematic layers, which are the driving time, bus time, walking time and cycling time from the community to the nearest park. The four maps All layers are surface layers, and their representation methods are hierarchical statistical graphs. Therefore, each thematic layer also needs to specify parameters such as grading fields, grading numbers, grading colors, and grading methods to build a complete thematic layer style.

2. Configure the basemap data source. According to the existing thematic mapping results, the data sources required for the base map of Putuo District in Shanghai include: street-level administrative divisions, government residences, roads (including urban roads, railways, expressways, township roads and county roads), water systems . Publish these data to the geoserver server. When publishing, select the tile publishing format as application/x-protobuf; type=mapbox-vector, which is the format of vector tiles that conform to the mapbox standard. The service address of the published vector tile can be obtained from the TMS service list on the home page of geoserver.

3. Configure the symbol and font library. The configuration method of the symbol and font library has been introduced above. In this embodiment, the required symbols and fonts need to be extracted from the existing thematic map results, and the corresponding files are generated step by step. In addition, in this embodiment, tomcat is used as a service configuration tool for the symbol library and font library, and the configured symbol and font files are placed in the tomcat server and accessed through the service address provided by tomcat.

4. Configure the basemap layer style. According to the existing thematic mapping results, the base map layers that need to be configured include: Putuo District administrative division (including two layers of color bands), street-level administrative division lines, district-level government and sub-district government locations and their annotations, roads and Its notes, water system and its notes. The basemap layers are arranged in the order of surface, line, point, and annotation from bottom to top. At the same time, unified regulations are made on the naming of the top layer surface and line layers, so that they can still be maintained when adding thematic layers later. Reasonable layer order.

5. Load the entire thematic map through the online intelligent thematic map compilation system. The process of loading a thematic map is divided into two parts: one is to load the configured basemap file, and the other is to load the thematic layer data generated by spatial analysis, and add thematic layers sequentially according to the style specified in the map template to form The entire thematic map. After the map is loaded, you can edit the thematic layer, interact and export the thematic map through other functional modules of the system.

During specific implementation, software can be used to realize the automatic operation of the process. Devices for running the process should also be within the protection scope of the present invention.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the technical field to which the present invention belongs may make various modifications or supplements to the described specific embodiments or replace them in similar ways.

Claims (5)

1. an online intelligent thematic map preparation method, is characterized in that, comprises the steps: Step 1. Build thematic map templates, including general templates for spatial analysis results and comprehensive templates for thematic mapping results; Step 2, according to the requirements of thematic map drawing, construct a base map style file that conforms to the mapbox style standard; Step 3: Build the framework of the online intelligent thematic mapping system, which supports loading the entire thematic map through the online intelligent thematic map compilation system; the process of loading the thematic map is divided into two parts, one is to load the configured base map file, and the other is to load the The thematic layer data generated by spatial analysis, according to the style specified in the thematic map template, add thematic layers in sequence to form the entire thematic map. 2. An online intelligent thematic map compilation method according to claim 1, characterized in that: in step 1, the thematic map template includes map basic information and thematic layer information, and thematic layer information includes layer basic information And layer style information, layer basic information includes layer id, name and layer type, layer style information includes layer visibility, layer representation method and layer style rules. 3. A kind of online intelligent thematic map preparation method according to claim 1, is characterized in that: in step 2, constructing basemap style file comprises the following substeps: Step 2.1, configure the basemap data source, publish the basemap data source in the corresponding server and obtain its service address; Step 2.2, configure the map symbol library data source, the symbol library data source conforms to the sprite format specified by Mapbox; Step 2.3, configure the map font library data source, the font library data source conforms to the font slice format specified by Mapbox; Step 2.4, configure the styled base map layer, and integrate the data sources in steps 2.1 to 2.3 to form a complete map style file. 4. An online intelligent thematic map compilation method according to claim 3, characterized in that: in steps 2.2 to 2.4, map symbols, fonts and base map style configurations can utilize existing thematic map drawing results to provide users with Style configuration reference. 5. According to claim 1 or 2 or 3 or 4 described a kind of online intelligent thematic map preparation method, it is characterized in that: in step 3, the page organization of the online intelligent thematic mapping system framework includes page style, component, configuration, page , five parts of tools; the page style part stipulates the style of each display module in the page; Components include four parts: ribbon bar, data item, layer item and layer data item in the page, and these four parts are responsible for interacting with data in the page; The configuration part includes service address, service acquisition command splicing and service acquisition interface. These parts cooperate with each other to form commands for adding, deleting, checking and modifying operations from the server side; The page part includes the data list, layer edit list, layer list and map display part, which form the basis of the entire previous page display; The tool part includes grading tools, color configuration tools and map editing tools, among which the grading tools are used to classify thematic data; the color configuration tool uses a color interpolation algorithm, which can convert the discrete color bands in the color library into continuous ones Grading and classification of colors to adapt to users for more levels of thematic coloring; map editing tools; use the tool interface in mapboxgl to edit the layer style and layer organization of the map.