CN110489499B

CN110489499B - On-line intelligent thematic map compiling method

Info

Publication number: CN110489499B
Application number: CN201910469409.0A
Authority: CN
Inventors: 亢孟军; 徐召硕; 苏世亮; 翁敏
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2022-11-18
Anticipated expiration: 2039-05-31
Also published as: CN110489499A

Abstract

The invention provides an online intelligent thematic map compiling method, which comprises the steps of constructing a thematic map template, wherein the thematic map template comprises a general template aiming at a space analysis result and a comprehensive template aiming at a thematic mapping result; constructing a base map style file which accords with a mapbox style standard according to the thematic map drawing requirements; constructing an online intelligent thematic mapping system framework, and supporting loading of the whole thematic map through an online intelligent thematic map compiling system; the process of loading the thematic map is divided into two parts, one part is to load the configured base map file, the other part is to load thematic map layer data generated by spatial analysis, and thematic map layers are sequentially added according to the patterns formulated in the thematic map template to form the whole thematic map. The template construction provided by the invention is beneficial to realizing the connection from the space analysis to the thematic charting function; when a thematic map template is constructed, a data organization framework is provided for a plurality of thematic representation methods, so that the user can edit the whole thematic map conveniently.

Description

On-line intelligent thematic map compiling 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

A thematic map (also called special map) is a map which highlights and perfectly represents one or more elements related to a theme on a geographic base map according to the requirements of the map theme, makes the map content thematic, has different expression forms and specialized application. The content of the thematic map consists of two parts: (1) the subject content. The natural or socioeconomic phenomena and their related features are highlighted on the figures. (2) A geographic basis. The general map contents for indicating the spatial position of the thematic element and the geographic background mainly include a graticule, a water system, a boundary, a residential area and the like. With the application of geographic information systems becoming more and more extensive, more and more fields are required for compiling thematic maps, the requirements of each field on thematic maps become more specialized and refined, the thematic maps need to be combined with specific spatial analysis results, meanwhile, the thematic maps need richer expression methods and expression forms, and also need to have more professional references in pattern configuration, and the thematic mapping method which is more specialized and can be combined with various thematic analysis results is particularly important under the background.

Currently, there are some methods for performing thematic mapping, but these methods have the following problems: firstly, the thematic map lacks a proper drawing template, and the space analysis result of a specific field cannot be directly converted into the thematic map with a more reasonable expression mode; secondly, the system construction of the thematic map editing function is not perfect, and the functions of whole map import and export, base map and thematic map layer editing, representation method switching, thematic map interaction and the like of the thematic map are difficult to realize in a coordinated manner; thirdly, the proposal of a relatively mature thematic map compiling method is lacked, and for the representation method of attribute elements, the style selection of thematic map layers and the like, the results of symbol libraries, color libraries, font libraries and the like from the existing mapping results are lacked.

With respect to online thematic mapping, the related background art is currently developing rather rapidly. In the aspect of transmission of spatial data, the application of a vector slicing technology is more and more extensive, the vector slicing technology preprocesses vector data into 'tiles' close to squares, when a webpage end calls the data, only the vector tile data under the current screen range and zoom level can be called, so that the data transmission quantity is greatly reduced, and meanwhile, compared with grid slicing, the vector slicing technology can be more flexibly and dynamically combined with a pattern file, so that the real-time performance and the flexibility of rendering are improved; in the aspect of map rendering, a Web Graphics Library (WebGL for short) provides a vector Graphics rendering technology, and drawing tools such as mapbox, openlayers, mapnik and the like form a personalized interface for rendering and editing a front-end vector map by utilizing the WebGL technology, so that the map rendering method is more easy for a user to use; in the front-end framework construction layer, webpage framework technologies such as Vue, react and Angular support the webpage modules to be driven through data, and the flexibility of webpage development is increased.

Disclosure of Invention

The invention mainly solves the problems of the existing thematic map compiling methods and constructs a set of relatively perfect thematic map compiling system and system.

The technical scheme of the invention provides an online intelligent thematic map compiling method, which comprises the following steps:

step 1, constructing a thematic map template, which comprises a general template aiming at a space analysis result and a comprehensive template aiming at a thematic mapping result;

step 2, constructing a base map style file meeting the mapbox style standard according to the thematic map drawing requirements;

step 3, constructing an online intelligent thematic mapping system framework, supporting loading of the whole thematic map through an online intelligent thematic map compiling system; the process of loading the thematic map is divided into two parts, one part is to load a configured base map file, the other part is to load thematic map layer data generated by spatial analysis, and thematic map layers are sequentially added according to the pattern formulated in the thematic map template to form the whole thematic map.

In step 1, the thematic map template includes map basic information and thematic map layer information, the thematic map layer information includes map layer basic information and map layer style information, the map layer basic information includes id, name and map layer type of the map layer, and the map layer style information includes visibility of the map layer, a map layer representation method and a map layer style specification.

Moreover, in step 2, the step of constructing the base map style file comprises the following substeps:

step 2.1, configuring a base map data source, publishing the base map data source in a corresponding server and acquiring a service address of the base map data source;

step 2.2, configuring a map symbol library data source, wherein the symbol library data source conforms to the sprite format specified by Mapbox;

step 2.3, configuring a map font database data source, wherein the font database data source conforms to a font slice format specified by Mapbox;

and 2.4, configuring a patterned base map layer, and integrating the data sources in the steps 2.1-2.3 to form a complete map pattern file.

In addition, in the steps 2.2-2.4, the map symbols, the fonts and the base map style configuration can utilize the existing thematic map drawing results to provide style configuration reference for the user.

Moreover, the page organization of the online intelligent thematic mapping system framework in the step 3 comprises five parts including page styles, components, configuration, pages and tools;

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

the component comprises four parts, namely a color stripe strip, a data item, a layer item and a layer data item in a page, wherein the four parts all bear the function of interacting with data in the page;

the configuration part comprises a service address, a service acquisition command splicing part and a service acquisition interface, and the service address, the service acquisition command splicing part and the service acquisition interface are matched with each other to form a command for performing addition, deletion, check and change operations from a server side;

the page part comprises a data list, a layer edit list, a layer list and a map display part, and the data list, the layer edit list, the layer list and the map display part form the basis of the display of the whole front-section page;

the tool part comprises a grading tool, a color configuration tool and a map editing tool, wherein the grading tool is used for grading and classifying thematic data; the color configuration tool uses a color interpolation algorithm, and can convert discrete color bands in a color library into continuous classified colors in a grading way so as to adapt to the color setting of a theme with more levels by a user; a map editing tool; and carrying out map layer style editing and map layer organization editing operation by using a tool interface in the mapbox.

According to the intelligent thematic map compiling method, through the configuration of the universal template and the comprehensive template, a basic framework is provided for drawing based on spatial analysis and user-defined drawing, and various editing options are provided for a user according to the structure of the template. In addition, the method also fully absorbs the existing excellent thematic drawing results and constructs drawing resources such as a symbol library, a color library, a template library and the like.

Therefore, the invention has the following advantages: 1. the template is constructed to be beneficial to butt joint with a space analysis module, so that the connection from space analysis to thematic charting function is realized; 2. the invention provides a data organization framework for a plurality of thematic representation methods when constructing the thematic map template, so that a user can edit the whole thematic map by editing a certain module in the thematic map template and can refer to the existing drawing results in the editing process; 3. the invention provides a whole set of map rendering, editing, interacting and transmitting methods by taking a front-end mapping method library mapbox provided by a mapbox as a core tool library, and constructs a set of relatively perfect thematic map compilation system.

Drawings

Fig. 1 is a system configuration diagram of an embodiment of the present invention.

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

FIG. 3 is a schematic page organization diagram of an online thematic mapping system according to an embodiment of the present invention.

Detailed Description

For better understanding of the technical solutions of the present invention, the following detailed description of the present invention is made with reference to the accompanying drawings and examples.

The system structure adopted by the embodiment of the invention is shown in figure 1. A thematic map is organized in a map file format, and the map file consists of a map template and thematic data. The map template comprises a base map style file (comprising base map source data information, symbol and font information and base map style information), organization information of a thematic layer and style information of the thematic layer, wherein the base map style file is used by the thematic map. The map source data information may include a map slice address, and the symbol and font information may include a symbol, a font address. Whereas the operation of different parts of the map file forms different functions in the system: the rendering of the base map is realized by loading a base map file; editing thematic layer styles is completed by modifying thematic layer style information in a map template; the thematic map layer organization information in the map template is modified, and functions of adding, deleting, hiding, sequentially adjusting and the like of thematic maps can be performed; when the driving data of the thematic layer is combined with the map template, the interface provided by the mapbox can be used for realizing the thematic layer rendering function.

In the system, two different thematic map compilation requirements are met: one of the two ways is a mapping function combined with the spatial analysis result of a specific subject, which can provide different mapping templates for spatial analysis models of different subjects, form a map file by combining the mapping templates and the spatial analysis result, and render the whole subject map by analyzing the map file, thereby realizing seamless connection from spatial analysis to subject mapping; and secondly, the drawing function from nothing to nothing is realized, namely, the user is supported to select a drawing template, spatial data, attribute data and the like by himself to carry out personalized drawing. Two different drawing requirements require the system to provide different drawing templates and provide perfect thematic map editing and interaction functions.

The thematic map compiling method provided by the invention realizes the link between thematic charting and a spatial analysis model by constructing a thematic map template; the functional modules of map loading, editing, finishing, interaction, output and the like are realized through a vector map design tool provided by the mapbox; and constructing a thematic map style library by extracting the existing thematic map drawing result. The method realizes the butt joint of the space analysis and thematic mapping functions, provides a professional thematic map style reference for a user, and constructs a set of online intelligent thematic map compilation system with more complete functions and lighter weight.

The online intelligent thematic map compiling method provided by the embodiment comprises the following steps of:

step 1, constructing a thematic map template: a drawing template (hereinafter referred to as a universal template) for a specific thematic spatial analysis model and a drawing template (hereinafter referred to as an integrated template) for existing thematic map results are constructed, and information such as map basic information, base map data sources, thematic map layer organization, thematic map layer basic information, thematic map layer data sources and thematic map layer patterns is specified in the drawing templates.

The special subject templates are divided into a general template and a comprehensive template, which respectively correspond to a space analysis model and an existing special subject drawing result. The general structure of the thematic map template is shown in fig. 2, which includes two parts, namely map basic information and thematic map layer information. The map basic information includes Id, author, name, update date and base map file of the map, where the base map file may be a json (JavaScript Object notification, javaScript Object Notation, which is a lightweight data exchange format) Object, and may also be a link address corresponding to the json file. The thematic layer information comprises two parts, namely layer basic information and layer style information, wherein the layer basic information comprises layer id, layer name and layer type, the layer id is a basic identification for identifying a layer, the id value of each layer needs to be unique, the layer name is information for interface display, and the layer types are four types, namely point, line, polygon and image, and respectively represent the layers of point, line, surface and grid image types. The layer pattern information comprises visibility (namely display or non-display) of a layer, a layer representation method and a specific pattern specification, wherein the point layer representation method comprises a fixed point notation method, a thermal diagram method, a point number method and a positioning diagram method, the linear layer representation method comprises a linear notation method, the planar layer representation method comprises a grading statistical diagram method and a partitioning statistical diagram method, and the layer pattern specification describes pattern information such as color, symbol, size and the like of the layer.

The thematic map layers mainly comprise three thematic map layers of points, lines and surfaces according to different geographic element types, each map layer has different representation methods, and each representation method corresponds to different template organization modes. Therefore, the topic map template is constructed by abstracting the topic map into a whole set of drawing rules described by json objects according to the organization rules described in fig. 2. When the method is specifically implemented, the thematic map template can directly utilize the existing thematic drawing results.

Step 2, constructing a base map file: and constructing a base map style file meeting the mapbox style standard according to the requirements of thematic map making.

The base map file is essentially a json format style file conforming to a mapbox style standard, information such as base map information, a base map data source, a map style data source (including symbols and fonts), a layer organization, a layer style and the like is specified in the base map file, a tool mapbox for map rendering and editing in the mapbox can directly load the base map file, and the base map is rendered at the front end.

In the step 2, the step of constructing the base map style file comprises the following substeps:

and 2.1, configuring the base map data source, publishing the base map data source in a corresponding server and acquiring the service address of the base map data source.

The file format of the base map data source is generally vector slicing, the vector slicing service is generated by using a map service tool geoserver, and a vector slicing extension module of the geoserver provides a function of generating the vector slicing service. Uploading a shp (map layer file format developed by SHAFEFILE, ESRI company) file required by rendering a base map in a geoserver and issuing a layer, so that a corresponding vector slice service address can be obtained;

in the mapbox style standard, the format of the base map data source may be vector slice, grid, digital Elevation Model (DEM), geojson (a format that encodes various geographic data structures in conformity with the JSON standard), picture, and video. Whatever the data source, it is specified in the style file by the server address of the data source.

And 2.2, configuring the map symbol library, namely configuring a data source of the map symbol library, wherein the data source of the map symbol library conforms to the write format specified by Mapbox.

The map symbol library data source used in the Mapbox style file is in the form of sprite, the sprite is a form of storing all map symbols in a centralized mode, the sprite is composed of two parts, one part is a png picture formed by splicing all map symbol pictures, the other part is a json file describing all symbol names and position information in the png picture, and the Mapbox reduces communication frequency by constructing the sprite and improves system efficiency. Multiple svg (Scalable Vector Graphics, a Graphics format that describes two-dimensional Vector Graphics) symbol files can be converted into a sprite file using the spritezero-cli tool provided by mapbox.

Before configuring the map symbol library, extracting the svg files of commonly used thematic map symbols through the existing thematic drawing results, and unifying the sizes of the symbols. Thereafter, the set of svg symbol files is converted to a sprite file using a spritezero-cli tool. After the generation is finished, the sprite file is placed at the server, and the symbol library of the thematic map is appointed in the style file by referring to the address of the server.

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

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

The source file required by the configuration font library is a ttf or otf file of the required font, the font source file is converted into a font slice file through a node-fontnik tool, and the font slice file is also placed in a server and is referred by a style file.

Step 2.4, configuring the organization and the style of the base map layer, and constructing a complete style file: and (4) configuring the stylized base map layer by utilizing a mapbox studio or other tools, and integrating the data sources in the steps 2.1-2.3 to form a complete map style file.

The step is to construct the layer organization and the layer pattern of the base map file. The styles of the base map layers can utilize the existing drawing results, map style resources such as a color library, a symbol library and the like can be constructed by referring to the existing drawing results, and a thematic map style library is constructed on the basis of the map style resources.

The Mapbox style specification specifies a plurality of map style expressions, and style configuration can be performed with reference to the specification. Since the JSON format code for directly writing Style files is cumbersome, some Style file generation tools can be used to perform Style configuration of "what you see is what you get" Style, such as mapbox studio, maputnik, arcGIS Vector Tile Style Editor, and the like.

The configuration of the map data source and map resource portions in the style file has been described in steps 2.1-2.3. As for the configuration of the layer pattern and the layer organization, tools such as mapbox studio, mapputnik, arcGIS Vector Tile Style Editor and the like can be used. Taking mapbox studio as an example, firstly uploading data required by drawing to a working space, then drawing by using the data, configuring a map into a required style, and releasing the configured map style in the working space through a publish function after configuration is completed. After the release, the style file can be downloaded to the local to obtain the required layer organization and style code.

And integrating the data sources, and matching the pattern layers with the base map data source layers. The addresses of the base map data source, the symbol library data source, and the font library data source described in steps 2.1 to 2.3 are specified in the "source", "sprites", and "glyphs" fields in the style file, respectively. Meanwhile, the layer name specified in the "source-layer" field of each layer in the layer (layers) field needs to be consistent with the name of each layer configured in the geoserver, otherwise, each layer pattern cannot be matched with the corresponding data source, and the map rendering cannot be completed.

The method for configuring the base map file described in step 2 above is the most common case in the configuration of the base map file using vector slices as data sources, because the configuration process is complicated, and the present invention is provided for implementation reference by those skilled in the art. The base map data source of the thematic map can be a grid slice, a grid picture, DEM data and the like besides the configured vector slice, and the data source under other conditions can be directly obtained without independent configuration of the data source. The mapbox style specification also provides corresponding layer style expressions for these data sources.

Step 3, constructing an online thematic map compiling system by modules: and constructing an online intelligent thematic mapping system framework, and realizing functional modules such as model loading, map editing, map interaction, map export and the like.

Each functional module can be constructed through a webpage end, and comprises modules for template selection, map rendering, layer editing, map interaction, map export and the like. The core function of the web page end is realized by using an interface in a mapbox-gl.

In the embodiment, the main functional modules are 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 mapping system is shown in fig. 3, and the whole page resource comprises five parts of a page style, a component, a configuration, a page and a tool: the page style part specifies the style of each display module in the page; the component comprises four parts, namely a color stripe strip, a data item, a layer item and a layer data item in a page, wherein the four parts all bear the function of interacting with data in the page; the configuration part comprises a service address, a service acquisition command splicing part and a service acquisition interface, and the parts are matched with each other to form commands for operations such as adding, deleting, searching, changing and the like from a server side; the page part comprises a data list, a layer edit list, a layer list and a map display part, and the data list, the layer edit list, the layer list and the map display part form the basis of the display of the whole front-section page; the tool part mainly comprises a grading tool, a color configuration tool and a map editing tool, wherein the grading tool comprises several common data grading methods for grading and classifying thematic data, a color interpolation algorithm is used in the color configuration tool, discrete color bands in a color library can be converted into continuous grading and classifying colors so as to adapt to the fact that a user sets colors for thematic on more levels, and the map editing tool mainly utilizes a tool interface in mapbox to carry out operations such as map layer style editing, map layer organization editing and the like. The functions of each module are completed through a separate file to increase the reusability of the modules.

In specific implementation, the front-end framework of the drawing system is organized according to the structure of fig. 3, and the reusability of the modules is ensured by loose coupling among the modules.

The implementation method of the whole online intelligent thematic map compilation is introduced by taking the park green space supply blind area analysis model in the Putuo area range of the Shanghai city as an example as follows:

1. and constructing a map universal template. First, basic information such as map id, name, author, update date, etc. is designated (the address information of the base map is filled in after the configuration in the subsequent step is completed). And secondly, configuring thematic map layer organization and style information, wherein a map template of the park green space supply blind area analysis model consists of 4 thematic map layers which are respectively driving time, bus time, walking time and riding time from a community to a nearest park, and the four map layers are all surface map layers, and the representing methods of the four map layers are all a hierarchical statistical map method, so that parameters such as a hierarchical field, a hierarchical number, a hierarchical color, a hierarchical method and the like are required to be appointed for each thematic map layer to construct a complete thematic map layer style.

2. And configuring a base map data source. According to the existing thematic drawing results, the data sources required for obtaining the base map of the Putuo district in Shanghai city comprise: street level administrative divisions, government premises, roads (including urban roads, railways, highways, rural roads, and county roads), water systems. The data are published to a geoserver server, and the slice publishing format is selected as application/x-protobuf during publication; type = mapbox-vector, which is the format of a vector slice that conforms to the mapbox standard. The service address of the issued vector slice may be obtained from the TMS service list of the geoserver home page.

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

4. And configuring base map layer styles. According to the existing thematic drawing result, the base map layer required to be configured comprises: the general top area administrative division (comprising two layers of colored bands), the street level administrative division line, the district level government and the street government parking place and the note thereof, the road and the note thereof, and the water system and the note thereof. The bottom map layers are arranged according to the sequence of surface, line, point and mark from bottom to top, and simultaneously, the names of the top planar layer and the top linear layer are uniformly specified, so that the reasonable layer sequence is still kept when the thematic layer is added subsequently.

5. And loading the whole thematic map through an online intelligent thematic map compiling system. The process of loading the thematic map is divided into two parts: one part is to load the configured base map file, the other part is to load the thematic map layer data generated by the spatial analysis, and thematic map layers are sequentially added according to the pattern formulated in the map template to form the whole thematic map. After the map loading is finished, the operations of editing thematic map layers, interacting and exporting thematic maps and the like can be performed through other functional modules of the system.

In specific implementation, the automatic operation of the process can be realized by adopting a software mode. Devices that operate a process should also be within the scope of the present invention.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives in a similar manner to those skilled in the art to which the present invention pertains.

Claims

1. An online intelligent thematic map compilation method is characterized by comprising the following steps:

step 3, constructing an online intelligent thematic mapping system framework, and supporting loading of the whole thematic map through an online intelligent thematic map compiling system; the process of loading the thematic map is divided into two parts, one part is to load the configured base map file, the other part is to load thematic map layer data generated by spatial analysis, and thematic map layers are sequentially added according to the patterns formulated in the thematic map template to form the whole thematic map.

2. The on-line intelligent thematic map making method according to claim 1, characterized in that: in step 1, the thematic map template includes map basic information and thematic map layer information, the thematic map layer information includes map layer basic information and map layer style information, the map layer basic information includes id, name and map layer type of the map layer, and the map layer style information includes map layer visibility, map layer representation method and map layer style specification.

3. The method for on-line intelligent thematic mapping according to claim 1, wherein: in step 2, the base map style file construction comprises the following substeps:

step 2.3, configuring a map font library data source, wherein the font library data source conforms to a font slice format specified by Mapbox;

4. The on-line intelligent thematic map making method according to claim 3, characterized in that: in the steps 2.2-2.4, the map symbols, the fonts and the base map style configuration can utilize the existing thematic map drawing results to provide style configuration reference for the user.

5. The on-line intelligent thematic mapping method according to claim 1, 2, 3 or 4, characterized in that: the page organization of the online intelligent thematic mapping system framework in the step 3 comprises five parts including page styles, components, configuration, pages and tools; the page style part specifies the style of each display module in the page;