CN110688443A

CN110688443A - Map annotation model and annotation method thereof

Info

Publication number: CN110688443A
Application number: CN201910977485.2A
Authority: CN
Inventors: 付宗堂; 方坤; 程圆圆
Original assignee: China University of Geosciences Beijing
Current assignee: China University of Geosciences Beijing
Priority date: 2019-10-15
Filing date: 2019-10-15
Publication date: 2020-01-14
Anticipated expiration: 2039-10-15
Also published as: CN110688443B

Abstract

The invention discloses a map annotation model and an annotation method thereof, wherein the map annotation model comprises the following steps: and finally determining the flow direction, the position and the area of the annotation through the control of the content density of the map. The optimal position of the annotation is depicted. The characteristics and the state of water flow flowing between the ridges and the valleys are converted into the characteristics and the state of the map notes, so that the positions and the density of the map notes and the elements in the map are converted into digital calculation in the model from visual perception, and the distribution of the map notes and the elements is evaluated. The map annotation water flow model describes the distribution and complexity of the map annotations from the quantitative angle, and accurately expresses the distribution and quantity relationship of the map annotations and elements. The invention has the advantages that: the defect that the prior art is based on single element annotation is overcome, and the capping problem of multi-layer annotation is effectively solved; the balance layout of the whole map and the balance of the map content are realized; the drawing efficiency is improved; the theory and the technical method of quantitative map making are enriched.

Description

Map annotation model and annotation method thereof

Technical Field

The invention relates to the technical field of map annotation, in particular to a map annotation model and an annotation method thereof.

Background

The map is an abstract expression of the real world, wherein various ground features in the reality are extracted into various symbols and marks to be expressed on a two-dimensional plane or a three-dimensional space. Various information is given to the map through map symbols, map marks, rendering of various colors and mathematical elements, and people can obtain various information required in life and production through the map contents. In many map contents, map annotations are the most intuitive map language reflecting map information in a limited space of the map contents, and if a map only has graphics and symbols without any annotation information, the map can only express the general spatial distribution concept of a spatial geographic area and cannot reflect the names, certain quantities and quality characteristics of geographic objects. The quality of the map directly affects the acquisition of information, and a map with ambiguous contents and ambiguity causes great inconvenience to map users and even conveys wrong information. As an important component of a map, the quality of a map annotation directly determines the quality of a map.

The map annotation is to place the descriptive content of the corresponding elements of the map at the periphery of the elements to realize the interpretation function, and the form of the annotation generally comprises text and numbers, as shown in fig. 1.

The four areas in fig. 1 are representations of map notations, the name of the village in fig. 1 is bowling, the characters in fig. 2 indicate that the construction material of the bridge on the main road is cement, the numbers indicate the attribute of the bridge, i.e. bearing 13T, the numbers in the passing months of 10-9 months and 3 indicate that the elevation of the mountain is 358 meters, the pavement material indicating the main road in fig. 4 is asphalt, the pavement width is 7 meters, and the roadbed width is 9 meters.

As can be seen from fig. 1, the selection of the annotation position is a crucial part, and improper selection of the position may cause the overlapping of the map annotation and the imbalance of the map image content. When the computer map technology is not popular, maps are often drawn manually, and map annotation configuration is also performed manually by drawing personnel. With the development of computer technology, the map making is developed from the prior manual drawing to the automatic drawing of a computer, and the configuration of the map notes improves the efficiency. However, the automatic configuration of the map annotation at present has certain defects, although the automatic configuration of the map annotation can be realized to a certain extent, in the case of a map with complex content, the map annotation is still accompanied with a lot of manual interactions during actual drawing, and the automatic configuration of the map annotation is a difficult problem in drawing. Therefore, a new map annotation configuration method is needed to solve the problem of map annotation automatic configuration.

With the development of geographic information technology, the current map making is basically completed based on GIS software, different software uses different rules for the annotation of the map, and the map making efficiency is integrally improved. Currently, commercial GIS software is numerous, but there is no systematic solution in the aspect of automatic configuration of map annotation. At present, the two optimal software in international and domestic are taken as the prior technical scheme.

ArcGIS is specialized geographic information data acquisition, data processing, data analysis and data rendering integrated software of ESRI company in America, and provides rich map making functions. In the aspect of map annotation configuration, the ArcGIS software proposes a method for performing annotation configuration on point elements, line elements and surface elements respectively. When the point elements are marked, the software sets several different priorities for eight directions around the point elements respectively, a user can select different positions for marking according to the covering condition of the marks, and the system performs overall configuration on the marked positions of the point elements according to the priorities selected by the user; when the line elements are marked, the software provides three forms of marking above the line elements, on the line elements and below the line elements for a user, the marking can be carried out at one time, the marking can be repeated in a segmented mode, and the word direction is configured according to the direction specified by the user; in configuring the face element with the annotation, the software provides the user with both horizontal and oblique annotation, which is typically located in the center of the face element.

As shown in fig. 2, the ArcGIS software sets a series of general rules for map annotation, wherein 2a is a point element annotation rule, the middle white frame represents the position of a geographic object, eight positions where annotation contents can be placed are arranged around the position, the position is given priority, when the optimal position 1 conflicts with other map contents, the position is selected as position 2, and if the conflict still exists, the position is selected as position 3; 2b is a line element marking rule, provides three modes of marking on line, pressing line and under line, and can set offset; and 2c is a marking rule of the surface element, the marking is written in the element, and three modes of horizontal marking, linear marking and horizontal-first-then-linear marking are provided.

The MapGIS is professional geographic information system software of digital science and technology limited in Wuhan, China, and has obvious advantages in geological mapping, and not only provides a professional geological symbol library, but also defines a coordinate system of a geological map. In the aspect of map annotation, the software also divides three elements of a point line surface into three elements to establish annotation rules.

As shown in fig. 3, MapGIS also makes a general rule for the annotation of the map, in which the annotation rule of the dot elements is that the default annotation position is right above the dot symbol, and then finally determines the annotation position by defining the offset, as shown in fig. 3 a. The marking of the line provides three ways of marking at the middle point of the line, equally distributing the marking words on the whole line, dividing the longer line into a plurality of parts, repeatedly marking each part, and the like, as shown in fig. 3 b. For a face element, the center position of the area is first calculated, and the annotation position of the face element is determined, as shown in fig. 3 c.

The existing map drawing software finishes the positioning of the notes by adopting a rule making mode about the notes of the map, provides a batch processing tool for the map notes to a certain extent, and improves the drawing efficiency. In the face of complex drawing requirements, the existing method has many defects, which are mainly represented as follows:

(1) the marking rule of the single elements of the point, line and surface is that the whole layer executes a rule, namely if the point element is selected to mark at the upper right corner, the whole layer executes the marking rule, and for marks which do not meet the requirement, manual intervention of a drawing worker is needed, and marking position selection is carried out point by point, so that the workload of map editing is greatly increased, and the drawing efficiency is seriously influenced;

(2) the map is a complex whole, and the annotation rule based on point, line and surface elements only considers the selection of the annotation position of one element type in the same element type (layer), so that the problem of space occupation and gland among annotations when multiple elements are superposed cannot be solved;

(3) the lack of quantitative computation for the location of the map annotation does not determine the optimal location of the annotation by building a map annotation localization model.

Abbreviations and Key term definitions

The map is marked with a water flow model: the map annotation water flow model obtains the distribution rule of the current map surface content by carrying out quantitative calculation on the map annotation and the element distribution rule in the map surface, and can accurately obtain which local elements and annotations are distributed more densely and which local elements and annotations are distributed more sparsely through the model, thereby providing an optimal position for the map annotation.

Map annotation configuration: the annotation configuration is a function of placing the descriptive contents of the corresponding elements of the map at the periphery of the elements to realize the explanation, and the selection of the annotation position is important to determine the balance of the map drawing.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a map annotation model and an annotation method thereof, which solve the defects in the prior art.

In order to realize the purpose, the technical scheme adopted by the invention is as follows:

a map annotation model is used for recognizing the annotation of a map as a river flowing between mountains, and finally determining the flow direction, the position and the area of water flow through elevation control. To draw the best position for the annotation at that moment. The characteristics and the state of water flow flowing between the ridges and the valleys are converted into the characteristics and the state of the map notes, so that the positions and the density degree of the map notes and the elements in the map are converted into digital calculation in the model from visual perception, and the overall evaluation on the distribution of the map notes and the elements can be performed. The map annotation water flow model can describe the distribution and complexity of the map annotations from the quantitative perspective, and can accurately express the distribution and quantity relationship of the map annotations and elements visually.

The map annotation model comprises a map content density model and a map annotation water flow model

The map content density model is a visual model obtained by quantifying the element symbols of the map and the distribution marked in the map and abstracting the element symbols and the distribution into space, and the values in the model are the result of assigning values of each grid according to an assignment rule.

The map annotation water flow model is formed by adding a map element annotation sequence, an annotation constraint rule and an annotation configuration rule on the basis of a map content density model.

A construction method of a map annotation model comprises the following steps:

step 1, constructing a map content density model;

(1) dividing grid units, wherein the minimum parameter of the number of all surface feature elements in a map is used as the side length of the divided grid units;

(2) the determination of the assignment rule or rules,

according to different visual variables of the element symbols and the annotation contents, different assignment rules are respectively established for various element symbols and annotations.

Element symbol assignment rule: the point symbols are assigned according to three visual variables of complexity, size and color, wherein a single point symbol in the complexity is assigned with 1, and a combined point symbol is assigned with 2; respectively assigning 1, 2, 3 and 4 according to the size of the symbol; the symbol color is assigned a value of 2 for black and 1 for the other colors. The line symbols are assigned with two visual variables of line type and color, wherein a single line type symbol is assigned with 1, and a combined line type symbol is assigned with 2; complex linear symbol assignment 3; the face symbol is assigned according to the brightness value of the background color, and the region with high brightness value is assigned with low value.

Annotation content assignment rules: the annotations are assigned values in two visual variables, grade and color. Wherein, according to the marking grade (size), from small to large, the values are respectively assigned as 1, 2, 3, 4 and 5; the note color is black with value 2, and other colors are assigned with value 1; in order to avoid the capping of the annotation content, the base value 2 is assigned to the annotation content in a unified manner.

And accumulating the assignment of the element symbols of the grid cells and the assignment of the mark content to obtain the score of each grid.

(3) Generation of map content density model

Dividing the map into N element classes, determining a grid unit by taking the size of the character number of the element class with the smallest marked character number as the side length, arranging all layers in the map according to a level sequence, respectively assigning the grid according to an assignment rule, and superposing the assignment results of all the layers to obtain a grid value in a final model.

Step 2, water flow model is marked on map

(1) Map element annotation sequence determination

The principle of determining the layer annotation sequence is to use the hierarchical thought of rivers to represent the complexity of the layer annotation content in a map, the layer with the more complex annotation content is annotated first, and the layer with the simpler annotation content is placed at the last annotation, so as to ensure the minimum annotation adjustment and calculation work. Meanwhile, the position of the layer with the annotation sequence at the back needs to be adjusted in the available space after the complex annotation is completed, so that the annotation accuracy of the high-level layer is ensured. After the layer annotation sequence is determined, the layer which is firstly annotated is called a first layer, and the other layers are called non-first layers. Generally, a point element layer with the lowest administrative level (with a large number of notes) in a map sheet is selected as a first layer, and the note sequence of non-first layers is determined according to the number of the layer notes. After the map element symbols are loaded, the map surface has no annotation content, so that when the first map layer is annotated, a map content density model is built only according to the element symbols, and then the first map layer is annotated by adopting an annotation rule; next, updating the map content density model according to the annotation content of the first layer and the map element symbol, and calculating the optimal position for the annotation of the next layer; loading a new layer, and completing the annotation of the new layer on the basis of the annotation constraint rule and the annotation configuration rule according to the idea of the map annotation water flow model; updating the map content density model again; and sequentially circulating until the marking work of all the layers is completed.

(2) Annotation constraint rules

The following annotation constraint rules are formulated to ensure the coupling relationship between the annotation content and the key element symbols.

1) Element notes cannot span different administrative areas;

2) element annotations cannot span different drawings;

3) the direction of the line element note is consistent with that of the element, and when the line element is too long, the line element note needs to be marked in a segmented mode;

(3) rule for arranging notes

And according to the characteristics of the map annotation water flow model, establishing a corresponding annotation configuration rule. The method specifically comprises the following steps:

1) the point elements need to be marked around the element symbols, and the number of the marked characters is within 5 times of the neighborhood range;

2) line elements need to be marked on both sides of element symbols, and are marked in the buffer area range of 5 times of character numbers;

3) the face elements need to be noted within the element boundaries.

(4) Work flow of map annotation

1) Loading a first layer, and marking the first layer by using a marking rule;

2) loading a non-first layer;

3) constructing a map content density model;

4) marking a non-first layer by using a map marking water flow model;

further, steps 1) and 4) in the workflow of map annotation require annotation of configuration rules and annotation of constraint rules.

Compared with the prior art, the invention has the advantages that:

1. the proposal of the map annotation water flow model concept determines the optimal position of the map annotation from the quantitative angle, overcomes the defect that the prior technical scheme is based on single element annotation, and effectively solves the capping problem of multi-layer annotation;

2. the calculation method based on the map content density model carries out quantitative analysis on the element symbols and the notes, and realizes the balanced layout of the whole map and the balance of the map content under the control of the note constraint rule and the note configuration rule;

3. according to the technical scheme, the automation of the whole map annotation can be realized, and the drawing efficiency is greatly improved.

4. The map water flow model provides a beneficial reference for intelligent map making, and enriches the theory and technical method of quantitative map making.

Drawings

FIG. 1 is a prior art map annotation diagram.

FIG. 2 is a schematic diagram of a mapping rule of ArcGIS in the prior art;

FIG. 3 is a schematic diagram of the mapping rules of the prior art MapGIS;

FIG. 4 is a Digital Elevation Model (DEM) diagram;

FIG. 5 is a map content density model diagram according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating assignment rules for diacritics and notations in accordance with an embodiment of the present invention;

FIG. 7 is a map (local) of the basic geographic information of Sichuan province in accordance with an embodiment of the present invention;

FIG. 8 is a schematic diagram of a process for generating a map content density model according to an embodiment of the present invention;

FIG. 9 is a map content density model diagram according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a rule for configuring a token according to an embodiment of the present invention;

FIG. 11 is a flowchart illustrating the operation of map annotation according to an embodiment of the present invention;

FIG. 12 is a grid of test areas in accordance with an embodiment of the present invention;

FIG. 13 is a first layer map content density model in accordance with an embodiment of the present invention;

FIG. 14 is a annotation result of a map annotation waterflow model according to an embodiment of the present invention;

fig. 15 is a map annotation result of the related art ArcGIS.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings by way of examples.

The map annotation water flow model provided by the invention is based on the visual description of a digital elevation model on the terrain, and is shown in figure 4. As can be seen from the digital elevation model diagram, the light color represents ridges with larger elevations, the dark color represents valleys with lower elevations, and the intermediate color represents hills with terrain transitions. The ridge line is the boundary line of the water flow, and a water catchment area is formed between the ridges. The direction of the water flow is from high to low, and finally the water flow is converged into a river. And taking the map annotation as a basic starting point, and defining a map annotation water flow model of the distribution and quantity relation of the map annotation. The key of the model is to construct a map content density model similar to the DEM characteristics, and according to the model, the optimal configuration scheme of map annotation is determined by combining a specific annotation rule.

The degree of density of the notes and the elements can be similar to the ridges and valleys in the terrain, the high places can be regarded as the ridges formed by stacking the notes and the dense parts of the elements, and the low places can be regarded as the valleys formed by the sparse parts of the notes and the elements. The process of map annotation can be regarded as the process of river flowing between the ridge and the valley: the level of the annotation can be regarded as the level of a river, the river has a main stream and a branch stream, the main stream is formed by gathering a series of branch streams with different levels, the hierarchical relationship can be similar to the hierarchical relationship of the annotation of each map layer in a map, the map layers in the map have different annotation elements according to different representation contents of the map layers, and the map annotation can be divided into different levels according to the annotation elements such as the size, the font, the color and the like of the annotation; the range of distribution of the annotations in the map can be regarded as the river basin, the river basin is limited to the part between two ridges and generally flows in the valley, and the annotations should also avoid crossing administrative regions and crossing elements in the process of configuration.

Meanwhile, the method selects a place with sparse annotation on the map, avoids elements for annotation, prevents the situation that the annotations are mutually overlapped or the elements are completely stamped and covered, and the selection range of the annotation position is a valley area of the model, namely a low-lying place in the model.

Map content density model

The distribution of the map annotations can be illustrated by a map content density model, as shown in fig. 5.

The content of the map comprises two parts of an element symbol and a map annotation. The map content density model is a result of quantifying the distribution of the element symbols and the annotations in the map, abstracting the distribution into a visual model on the space, and assigning values in the model to each grid according to an assignment rule. The height of the cylinder body represents the height of the grid value, the height of the numerical value in the model can intuitively and quantitatively reflect the sparseness degree of the map marks and the element symbols, wherein the cylinder area with higher value represents the area with denser element symbols and marks, namely the position of the ridge; the lower value cylinder regions represent regions in the map where elements and annotations are sparser, i.e., "valley" locations in the model. The model abstracts the selection process of the map annotation position into the process that water flows in the model, i.e. the annotation content is imagined into a single character or number and is thrown from the top of the model, and finally the annotation position is tracked to be in the valley area with sparse element symbols and annotations.

The map content density model building method mainly comprises three parts of grid unit division, assignment rule determination and density model generation.

(1) Partitioning of grid cells

The purpose of grid establishment is to quantify the specific positions of various element symbols and notes in the map, so the word size of the smallest noted word in the map will be the key factor controlling the size of the grid. The minimum parameter of the word size of all surface feature elements in the map is used as the side length of the divided grid unit, so that the grid unit can be ensured to be as fine as possible within a controllable range, and the problem of low calculation efficiency caused by over-small determined grid unit is avoided.

(2) Determination of assignment rules

In the regular mesh DEM, the value associated with each mesh is the elevation information of the point, while in the map content density model, a numerical data is used to represent the distribution characteristics and intensity of the map annotation and element in each mesh. In the map, elements are usually abstracted to map symbols for expression, map notes are expressed by characters or numbers, and different assignment rules are respectively established for various element symbols and notes according to the difference of visual variables of the element symbols and the notes because the use effect of the map is influenced by the visual variables, as shown in fig. 6.

Taking the point symbols as an example, considering three visual variables of complexity, size and color of the symbols, and performing classified assignment according to the composition and the level of the symbols to finally obtain the total assignment amount; similarly, the notes are respectively assigned according to three visual variables of characters, numbers, grades (sizes) and colors, and the total assigned value is calculated. The total number of assignments represents the occupation and frequency of the element symbols and the annotations (map content) in the grid, and reflects the density distribution of the map content.

(3) Generation of map content density model

A part of the basic geographic map of the province of Sichuan is used for explaining how to generate the map content density model (as shown in fig. 7).

The map comprises five element classes (layers) which are respectively a provincial administrative division surface element, a provincial meeting level point element, a local city level point element, a county level point element and a river line element, wherein the size of the number of the county level point element with the smallest number is used as the side length to determine a grid unit, all layers in the map are arranged according to the level sequence, the grid is respectively assigned according to assignment rules, the assignment results of all the layers are superposed to obtain the grid value in a final model, and the assignment and superposition processes of the grid are shown in FIG. 8.

The lowest layer of fig. 8 is the accumulated value of the assignment results of the element symbols and the notes in fig. 7, the four boxes in fig. 8 are the amplification effect of the assignment results of the grid, and the numbers indicate the distribution and density of the map content. The maximum value in the left red frame is 30, which reflects that the map content density of the area is the maximum and is not suitable for marking; the minimum value is 4, which means that the map content is less and is an ideal position for adding new notes. Generally, the continuous models are all expressed in the form of gradient, the assignment result of fig. 8 is expressed by using gray values, and the final map content density model is formed as shown in fig. 9. 9a is a map content distribution diagram of the research area, and the darker the color is, the more the map content distribution is, the map content distribution is not suitable for marking; the lighter the color indicates less map content, respectively, and the area is suitable for annotating new elements. 9b reflects that the optimal position of the annotation should be from a dark color to a light color, i.e. 9c indicates the optimal position area of the annotation.

Map water flow model

The distribution characteristics of the map element symbols and the marks are quantitatively expressed through a map content density model, and on the basis, the map element mark sequence, mark constraint rules and mark configuration rules are added to form a map mark water flow model.

(1) Map element annotation sequence determination

The determination of the annotation sequence of map elements (map layers) is an important part in the annotation configuration process (which is also a problem that cannot be solved by the prior art scheme), and the principle of determining the annotation sequence of map layers is to use the hierarchical idea of rivers to represent the complexity of the annotation content of map layers in a map, wherein the layer with the more complex annotation content is annotated first, and the layer with the simpler annotation content is placed at the last annotation, so as to ensure that the annotation adjustment and calculation work are minimum. Meanwhile, the position of the layer with the annotation sequence at the back needs to be adjusted in the available space after the complex annotation is completed, so that the annotation accuracy of the high-level layer is ensured. After the layer annotation sequence is determined, the layer which is firstly annotated is called a first layer, and the other layers are called non-first layers. Generally, a point element layer with the lowest administrative level (with a large number of notes) in a map sheet is selected as a first layer, and the note sequence of non-first layers is determined according to the number of the layer notes. After the map element symbols are loaded, the map surface has no annotation content, so that when the first map layer is annotated, a map content density model is built only according to the element symbols, and then the first map layer is annotated by adopting an annotation rule; next, according to the method of fig. 8, updating the map content density model according to the annotation content of the first layer and the map element symbol, and calculating the optimal position for the annotation of the next layer; loading a new layer, and completing the annotation of the new layer on the basis of the annotation constraint rule and the annotation configuration rule according to the idea of the map annotation water flow model; updating the map content density model again; and sequentially circulating until the marking work of all the layers is completed.

(2) Annotation constraint rules

Although the optimal position of the annotation can be calculated by the map content density model, the following annotation constraint rule is required to be established to ensure the coupling relationship between the annotation content and the element symbol in consideration of the dependence relationship between the annotation and the element symbol.

3) Element notes cannot span different administrative areas;

4) element annotations cannot span different drawings;

(3) rule for arranging notes

1) the point elements need to be marked around the element symbols, and in the neighborhood range 5 times the number of the marked characters, as shown in fig. 10 a;

2) line elements need to be marked on both sides of the element symbol within the buffer area with 5 times of the number of the marked character as shown in fig. 10 b;

3) the face elements need to be noted within the element boundaries as shown in fig. 10 c.

(4) Work flow of map annotation

On the basis that the map content density model carries out comprehensive quantification on the map contents, the annotation work of the whole map can be completed by combining the annotation sequence, the annotation constraint rule and the annotation configuration rule of the whole map elements, and the specific work flow is shown in fig. 11.

As can be seen from fig. 11, the map annotation is completed in two steps, namely, the map content density model and the annotation of the map layer are constructed. Firstly, loading all the element symbols for drawing, and constructing a map content density model according to the assignment rule of the element symbols under the control of a regular grid; then, selecting a marking layer according to a marking sequence, wherein a first layer is required to be selected for the first time, and then sequentially selecting non-first layers in a cycle; finally, under the combined action of the annotation configuration rule and the annotation constraint rule, the annotation of the image layer is completed; and updating the map content density model according to the annotation content assignment rule, calculating the optimal position for the annotation of the next layer, and repeating the steps until the annotation of the last layer is completed. On the basis of finishing the map annotation, a content density model of the cost map is generated at the same time and can be used as the basis of map evaluation.

In the embodiment 1, partial data in the administrative division of Nanjing city in Jiangsu province is selected as map annotation experimental data, the data comprises geographical elements such as rivers, lakes, province cities, county and district residences, town streets, administrative districts and the like, and the element types cover three types of point elements, line elements and surface elements. According to the marking scheme of the map marking water flow model, the method comprises the following steps:

(1) determining annotation order

According to the dividing principle of the image layer annotation sequence, firstly, the area ratio of the annotation content in the map is calculated, and then the annotation sequence of the map layer is determined according to the area size and the number of the annotations. The sequence of the notes of each layer is as follows: the street map layers of villages and towns are selected as the first map layers of the notes.

(2) Grid for determining map content density model

And determining the size of the grid according to the size of the font of the first image layer of the note and the width of the image. Fig. 12 is a grid of test zones.

(3) Constructing a first map layer map content density model

And constructing a first layer map content density model according to the assignment rule of the element symbols, as shown in fig. 13.

(4) Non-head layer note

According to the workflow of fig. 11, the annotation of all the non-top image layers is completed, and the annotation result is shown in fig. 14. In order to compare the labeling effect of the map labeling water flow model, the data of the test area are labeled by the method of the first technical scheme, and the result is shown in fig. 15.

(5) Comparison of the results of the two protocols

From the comparison between fig. 14 and fig. 15, it can be found that the map annotation completed according to the map annotation water flow model and the annotation result of the first technical solution are very different, which is specifically shown in that:

1) the technical scheme is that the positions of point element marks are defined through priority, and fig. 15 shows that the mark positions are all in the upper left corner of a point symbol, so that more mark cross-border situations (east-ditch town, Tangshan street, east-screen town, Hangzhou village committee, Meta mountain street and the like) occur; and the first layer annotation using an annotation constraint rule has a good annotation effect.

2) According to the technical scheme, only the element annotation rule of the single layer is considered, and the relationship among the elements is not considered, so that a large amount of capping phenomena occur among annotations and element symbols of different layers, and the capping phenomena account for 52% of the total number of the annotations; the second invention adopts a step-by-step calculation mode to determine the optimal marking position, has fewer gland covers and is basically controlled within 10 percent.

3) For the region with dense annotations, the first technical solution is to control the capping ratio by omitting part of the annotations, for example, the rainflower platform area in fig. 14 is omitted in fig. 15, and the integrity of the content of the annotations cannot be guaranteed.

4) The technical scheme is that the notes of the line elements are marked by adopting character strings approximately parallel to the direction of the line elements, the whole character strings are integrally operated (a pan-tilt mountain river, a Qinhuai river and the like), the scheme is that the notes are marked by adopting single characters, the coupling with the line elements is better, and the segmented notes (Yangtze river) of the Yangtze river flow and the separated notes (the Qinhuai river) of the characters are realized.

5) In view of the layout of the whole map, the scheme has more uniform annotation and more balanced map contents.

It will be appreciated by those of ordinary skill in the art that the examples described herein are intended to assist the reader in understanding the manner in which the invention is practiced, and it is to be understood that the scope of the invention is not limited to such specifically recited statements and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims

1. A map annotation model, characterized by: the method comprises the following steps of (1) regarding a mark of a map as a river flowing between mountains, and finally determining the flow direction, position and area of water flow through elevation control; drawing the best position of the annotation at the moment; converting the characteristics and the state of water flow flowing between ridges and valleys into the characteristics and the state of the map notes, converting the positions and the density degrees of the map notes and the elements in the map into digital calculation in a model from visual perception, and performing overall evaluation on the distribution of the map notes and the elements; the map annotation water flow model describes the distribution and complexity of the map annotations from the quantitative angle, and can accurately express the distribution and quantity relationship of the map annotations and elements visually;

a map annotation model comprising: a map content density model and a map annotation water flow model;

the map content density model is a visual model obtained by quantifying the element symbols of the map and the distribution marked in the map and abstracting the element symbols and the distribution into space, and the values in the model are the result of assignment of each grid according to assignment rules;

2. The method for constructing the map annotation model according to claim 1, comprising the steps of:

step 1, constructing a map content density model;

(2) the determination of the assignment rule or rules,

according to different visual variables of the element symbols and the annotation contents, different assignment rules are respectively set for various element symbols and annotations;

element symbol assignment rule: the point symbols are assigned according to three visual variables of complexity, size and color, wherein a single point symbol in the complexity is assigned with 1, and a combined point symbol is assigned with 2; according to the size of the symbol, assigning values of 1, 2, 3 and 4 from small to large respectively; the symbol color is assigned a value of 2 for black and 1 for the other colors; the line symbols are assigned with two visual variables of line type and color, wherein a single line type symbol is assigned with 1, and a combined line type symbol is assigned with 2; complex linear symbol assignment 3; assigning the surface symbol according to the brightness value of the background color, and assigning the area with high brightness value to be low;

annotation content assignment rules: the notes are assigned with two visual variables of grade and color; wherein, according to the marking grade, the values are respectively assigned as 1, 2, 3, 4 and 5 from small to large; the note color is black with value 2, and other colors are assigned with value 1; in order to avoid the capping of the annotation content, a basic value 2 is uniformly assigned to the annotation content;

accumulating the assignment of the element symbols of the grid cells and the assignment of the annotation content to obtain the score of each grid;

(3) generation of map content density model

Dividing a map into N element classes, determining a grid unit by taking the size of the character number of the element class with the smallest marked character number as the side length, arranging all layers in the map according to a level sequence, respectively assigning the grid according to an assignment rule, and superposing the assignment results of all the layers to obtain a grid value in a final model;

step 2, water flow model is marked on map

(1) Map element annotation sequence determination

The principle of determining the layer annotation sequence is that the hierarchical thought of rivers is utilized, the complexity of the layer annotation content is expressed in a map, layers with more complex annotation content are annotated first, layers with simpler annotation content are placed on the last annotation, and the aim of ensuring that annotation adjustment and calculation work are minimum is achieved; meanwhile, the position of the layer with the annotation sequence at the back needs to be adjusted in the available space after the complex annotation is completed, so that the annotation accuracy of the high-level layer is ensured; after the layer annotation sequence is determined, the layer which is most annotated is called a first layer, and the other layers are called non-first layers; the first layer is generally the point element layer with the lowest administrative level in the map sheet. Firstly, a map content density model of a first layer is constructed according to an assignment rule of element symbols, and an optimal position is marked and calculated for the first layer; loading a first image layer, and completing the annotation of the first image layer on the basis of the annotation constraint rule and the annotation configuration rule according to the idea of the map annotation water flow model; then updating the map content density model according to the marking content and the element symbols of the first layer, marking the non-first layer, and circulating in sequence until the marking work of all layers is completed;

(2) annotation constraint rules

Making the following annotation constraint rules to ensure the coupling relation between the annotation content and the element symbols;

1) element notes cannot span different administrative areas;

2) element annotations cannot span different drawings;

(3) rule for arranging notes

According to the characteristics of the map annotation water flow model, making corresponding annotation configuration rules; the method specifically comprises the following steps:

3) the surface element needs to be marked within the element boundary;

(4) work flow of map annotation

1) Adding map element symbols to determine a regular grid;

2) constructing a map content density model;

3) selecting a note layer;

4) and marking the current map layer by using a map marking water flow model.

3. The method of claim 2, wherein: step 4) in the workflow of map annotation requires annotation configuration rules and annotation constraint rules.