JPH01181159A - Map display method - Google Patents

Abstract

PURPOSE:To obtain an easy-to-see screen showing a wide range by selecting and displaying the data on the trunk roads not the data on the streets in case a wide range is taken out of a map. CONSTITUTION:It is supposed that the map information on a certain range is stored in a memory part 1 and at the same time the data on the trunk roads are taken out and stored in the part 1. Then an operator designates a take-out area and a graphic processing part 4 judges whether said designation shows a narrow or wide display range. In case of a narrow display range, all information types are taken out of the part 1 and displayed on a CRT 2. While the part 4 selects the data on the trunk roads, the data on rivers and the data on railroads out of the part 1 and displays them on the CRT 2 in case of a wide display range.

Description

[Detailed Description of the Invention] A. Industrial Field of Application The present invention is also referred to as computer mapping, in which map information such as streets, buildings, railways, rivers, etc. is managed by a computer and displayed on a graphic CRT or the like. This relates to a map display method.

B1 Summary of the Invention The present invention provides a method for classifying map information into a plurality of information types and storing it in a storage unit, cutting out a designated display range from the stored data and displaying it on the display unit. Search for the vector group that makes up the arterial road from the constituent polygon data and store it separately.When cutting out a wide area, you can use the separately stored arterial road data instead of displaying the street data made up of polygon data. This makes the screen easier to see by making it a display target.

C1 Prior Art Recently, map information has been managed by a computer and displayed on a graphic CRT or the like in order to improve the efficiency of administrative management work.

In this display method, the map information processed by the host computer is stored on a magnetic disk, etc., and since the map information usually covers a wide area,
By specifying the area you want to display, map information within that area is extracted. This cutting-out situation is conceptually illustrated as shown in FIG. 3. Third
The figure shows map information stored in a magnetic disk that is cut out by specifying area A or area B surrounded by dotted lines and displayed on the screen of a graphic CRT by reducing a wide area or displaying a narrow area. FIG. 3 is a diagram showing an enlarged display of the image.

In addition, regarding the management of map information, it is necessary to digitalize map information, and regional positional relationships become important.
Coordinates indicating the location are given to each piece of map information. Furthermore, when each piece of information is broken down into data elements, these elements are vectors, symbols, and characters. This data management system is conceptually illustrated as shown in Figure 4.
For vector data (-), coordinates (X 2 + y
4) By giving (X4.y3), coordinates (x+, yt) are given for symbol data (△), and coordinates (X3.y+) are given for character data (AB). can be displayed respectively.

Problems to be solved by the D0 invention In general, the areas targeted by mapping systems are east and west,
It spans an area of several 10 km from north to south, and there are cases where the entire area or a fairly wide area is displayed, and cases where a specific narrow area is displayed. On the other hand, since the size of the tube surface of Graph Ink (, RT, etc.) that performs the actual display is fixed, when a wide range is displayed, the data becomes dense and the screen becomes difficult to see.

A specific example is shown below.

We have map information up to 41 streets wide as data, and display this map information at a scale of 1/1000.
and 1/20000. If the tube surface of a graphic CRT is 270x x, the scale is 1/100.
0, the actual distance is 2701 (270xiXl) on the tube surface.
ooo) range is displayed. At this time, the 41-wide road has an interval of 4xx on the display.

On the other hand, at a scale of 1/20000, the display range is 5400.
The range of M is displayed, but 4! The displayed interval of the width road is 0.2xx. This interval of 0.2zx cannot be realized with a graphic crt'r having a resolution of 1024 dots or more, which is normally used in mapping, and the points may become the same point or two points adjacent to each other. If this were to be carried out to display the entire area, the screen would be completely covered with the street data display, resulting in a meaningless display.

An object of the present invention is to make the screen easier to view and ensure meaningful display when displaying a wide range.

Means for Solving the E0 Problem The present invention classifies map information into a plurality of information types and stores them in a storage unit, and also allows an operator to select vectors constituting arterial roads from polygon data vectors representing city blocks in advance. The group is searched and stored as trunk road data of one information type in the storage unit separately from the street data, and then divided into multiple information types according to the size of the cutout area by the graphic processing unit. The present invention is characterized in that the type of information to be displayed is selected from the list, and when a wide range is to be extracted, self-recorded highway data is selected without selecting street data consisting of polygon data as the display target.

F Embodiment (1) Classification of map information In the embodiment of the present invention, map information is classified into information types such as streets, buildings, railways, and rivers and stored in the storage unit l shown in FIG.
Store in. The selection criteria for determining whether or not to display these information types is determined as follows.

Streets: When displaying a narrow range, the display target is displayed, but when displaying a wide range, only arterial roads (described later) are displayed.

Buildings: Due to the large amount of information, they are not displayed when displaying a wide area.

(2) Preservation of street data and trunk road data Among the above information types, street data includes the following.

There are some special characteristics. That is, the street data consists of a set of city blocks, and each city block is described as polygon data. Figure 2 is an explanatory diagram showing 8 blocks (8 polygons).
A to H indicate polygons, and symbols with numbers added to each alphabet indicate the coordinates of the polygon. For example, polygon A has coordinates A1 to A4, and when the coordinates of A1 to A4 are given as polygon data, vectors connecting A1 to A7, A and A3, and A3 and A4 are drawn, and finally A vector from the end point A3 to the start point A is drawn to form a polygon.

Here, streets are the parts between adjacent polygons,
For example, the vector connecting A t and A 3 and Bl.

This is the range sandwiched by the vectors connecting G4.

In Figure 2, the streets sandwiched by vectors extending in the vertical direction correspond to narrow roads: A3 and A4, G3 and G4, and G3.
and C4, the vector group consisting of G3 and G4, and E, and G2,
The street sandwiched between the vector groups consisting of Fl, G7, G, G1, H, and H corresponds to a wide road.

When displaying a wide range of such street data, in order to display only main roads, a group of vectors constituting a wide street is extracted from the polygon data and stored separately in the storage unit l. This trunk road data is extracted as follows.

(a) The operator issues an instruction to "start entering main road."

(b) Display the target area (narrow range) for input on the graphic CRT 2.

(c) Among the streets displayed on the graphic CRT 2, the operator uses the input device 3, such as a stylus pen, to indicate vectors that the operator has determined constitute a main road. In the initial state, no data exists in the area of the storage unit l that is intended to store trunk road data.

(d) The vector specified by the operator is searched from the street data (polygon data), and the vector is stored separately in the storage unit 1 as trunk road data forming one information type. At this time, the vector is displayed in different colors.

(e) Repeat steps (b) to (d).

(f) The operator issues an instruction to "end main road manual labor."

(g) Return the vector (group) data whose color was changed to indicate that it has been selected as trunk road data to its original color.

Of these, the graphic processing section 4 automatically performs the processing in (d) and (g).

(3) Execution of display Memory: A certain range of map information is stored in IRI1, and the retrieval of the main road data has been completed.
Suppose it is stored in . First, the operator specifies a cutout area (display range).

If this display range is narrow, the graphic processing unit I
All information types included in the display range, in this example street data (polygon data), building data, river data, and railway data, are extracted and displayed on the graphic CRT 2. On the other hand, when the display range is narrow, trunk road data, river data, and railway data are selected and displayed from among the information types included in the display range.

G Effects of the Invention According to the present invention, depending on the size of the cutout area, buildings,
Since the type of information to be displayed is selected from the types of information such as rivers, it is possible to display a screen that is appropriate for the purpose and is easy to see even when displaying a wide range. Moreover, only the main road data is extracted from the street data and stored separately, and when displaying a wide area, instead of displaying all streets, the main roads are displayed using the separately stored data. The screen becomes especially easy to see at points. Focusing on the fact that street data is represented by a set of blocks made up of polygons, vectors that make up arterial roads are searched and saved from the vectors of polygon data, so the streets displayed on the display are Since this can be done by instructing the operator to select a vector from among them using an input device such as a stylus pen, arterial road data can be easily created.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an example of an apparatus for carrying out the present invention, Fig. 2 is an explanatory drawing showing street data, Fig. 3 is an explanatory drawing showing how map information is extracted, and Fig. 4 is an explanatory drawing showing map information. It is an explanatory diagram showing a data management system. l...Storage unit, 2...Graphic CRT, 3...
- Input device, 4... graphic processing section. - Fig. 1: Figure 2: Figure 2: Number 28 (item 28)

Claims (1)

[Claims] (1) Map information is classified into multiple information types and stored in the storage unit, and street data is represented by a set of blocks, each block is described as polygon data consisting of a set of vectors, and the data in the storage unit is In this method, a specified display range is cut out by a graphic processing unit and displayed on a display unit, in which an operator searches in advance for a group of vectors constituting a main road from among the vectors of the polygon data, and divides these into one. The data is stored in the storage unit as main road data consisting of two information types, and the graphic processing unit selects the information type to be displayed from among the plurality of information types according to the size of the cutout area, and A map display method characterized in that when cutting out a range, the main road data is selected without selecting street data consisting of polygon data as a display target.