JP2001043350A - Display processing method for map data and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease even a large quantity of map data to undergo the coordinate transformation and to attain the fast display for the change of a reduction scale. SOLUTION: When a reduction scale change request is given from a user, a coordinate transformation ratio is calculated between a device coordinate system and an absolute coordinate system (402). Then a reference area is set to show an area range where the simple display is performed in the device coordinate system (403). A reference area of the absolute coordinate system is calculated from the set reference area and the coordinate transformation ratio and defined as a discrimination unable area (404). The map data expressed in the absolute coordinate system are read out (405) and the existing area of the map data is compared with the discrimination unable area (406). If the map data are larger than the discrimination unable area, the change of a reduction scale is displayed in a usual way (408, 409). If the map data are smaller than the discrimination unable area, the simplified display is performed (407).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to map data display processing, and more particularly to a map data display processing method and apparatus suitable for displaying vector map data and the like on a reduced scale.

[0002]

2. Description of the Related Art In a conventional vector map data display processing method, when display processing is performed in response to an instruction to change the display scale from a user, particularly when a reduced display is performed, FIG.
Character strings and broken lines that can be easily distinguished in a narrow area display of vector map data as in (a) become indistinguishable in an area display wider than (a) as shown in FIG. It is known that when an area is displayed, most figures cannot be distinguished as shown in FIG.

[0003] As a technical technique to deal with this,
For example, Japanese Patent Application Laid-Open Nos.
The thing described in 254355 gazette etc. is known.
This is when displaying the vector map data in a reduced size,
If the size is smaller than the size that cannot be visually distinguished on the display screen, it is displayed as an alternative display or is not thinned out and drawn.

In the display processing of map data, it is necessary to consider two types of coordinate systems, that is, absolute coordinates and device coordinates. The absolute coordinate system is also called a world coordinate, a Cartesian coordinate, or the like, and is a term generally used in the field of CAD / GIS. In the case of a GIS, it refers to a coordinate system for expressing map data itself. Map data always has a position with some point as a reference point, and this does not change regardless of the scale at which it is displayed on a graphic display or the like. One device coordinate is also a commonly used term, and is a coordinate system specific to a hardware device constituting the system. Usually, the output hardware device has a coordinate system indicated by dpi if it is a printer, and has a coordinate system indicated by pixels if it is a graphic display.

In the display processing of map data, a coordinate conversion ratio is calculated from a display range on an absolute coordinate system with respect to device coordinates, map data is obtained, map data is converted into device coordinates from the coordinate conversion ratio, and drawn on a converted device. Is performed. Here, the above-mentioned JP-A-10-25
No. 4355 discloses a method in which map data converted into a device coordinate system after a coordinate conversion process is used in order to thin out map data in which a figure cannot be discriminated. If it is larger than this, drawing processing is performed, and if it is smaller, processing such as thinning is performed.

As another conventional technique, a coordinate conversion ratio for executing thinning is set in advance for each map data, and after the coordinate conversion ratio is obtained, the obtained coordinate conversion ratio and the thinning set in the map data are set. There is also a method of comparing with the execution conversion ratio and determining whether to thin out or not.

[0007]

However, the technology described in Japanese Patent Application Laid-Open No. 10-254355 and the like is based on the premise that display determination is made based on map data coordinate-converted to a device coordinate system. There is a problem that it is impossible to determine whether or not display is possible without performing coordinate conversion processing including real number calculation for all map data elements.

In the method of thinning map data in comparison with the thinning execution coordinate conversion ratio set for each map data, the appropriate thinning execution coordinate conversion ratio must be set for all the map data to be displayed. In addition, it is not easy to change the conversion ratio, so that there is a problem that a heavy burden is imposed on a user who actually uses the conversion ratio.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and it is possible to reduce an increase in processing even when a large amount of vector map data or the like is to be displayed, and to put a burden on a user. It is another object of the present invention to speed up map display processing by minimizing coordinate conversion processing and display processing on a display for map data for which it is clear that a display result cannot be recognized by a user.

[0010]

In order to achieve the above object, a map data display processing method according to claim 1 calculates a coordinate conversion ratio between an apparatus coordinate system and an absolute coordinate system, and simplifies the processing in the apparatus coordinate system. A reference area indicating a range of an area to be displayed is set, and a reference area in an absolute coordinate system is calculated based on the reference area in the apparatus coordinate system and the coordinate conversion ratio, and the area is determined as an indistinguishable area. Is compared with the indistinguishable area. If the map data is larger, a normal scale change display process is performed. If the map data is smaller, a simplified display process is performed. Is performed.

According to a second aspect of the present invention, there is provided a map data display processing method, wherein an arbitrary numerical value or area input by a user is set as a reference area in the apparatus coordinate system.

According to a third aspect of the present invention, there is provided a map data display processing method, comprising: for each type of map data, display determination information indicating a criterion as to whether or not simplified display is to be performed; Is prepared, and the simplified display processing is executed based on the display control information at the time of the simplified display processing.

According to a fourth aspect of the present invention, there is provided a map data display processing device for storing map data expressed in an absolute coordinate system, calculating a coordinate conversion ratio between the device coordinate system and the absolute coordinate system, Means for setting a reference area indicating a range of an area for simplified display in the system, and a reference area in the absolute coordinate system based on the reference area in the apparatus coordinate system and the coordinate conversion ratio, and a non-discriminating area. Means for setting the map data in the absolute coordinate system with the indistinguishable area; and when the map data in the area is larger than the indistinguishable area, the map data And a means for converting and displaying the map data in the apparatus coordinate system based on the coordinate conversion ratio, and a means for simply displaying the map data when the area where the map data is present is smaller than the indistinguishable area. It is characterized in.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram of a map data display processing system according to an embodiment of the present invention. This map data display processing system includes an external storage device 1 for storing vector map data 200, and a central processing unit (C) for executing various processes such as a map data display process.
(PU) 6 and a memory 7 for storing various information, a display 3 for displaying vector map data, various screens, and the like, selecting menus on the screen, and performing various operations. And a mouse (pointing device) 5 and the like. The display 3, the keyboard 4, and the mouse 5 may be collectively used as a terminal device and connected to the data processing device 2 as a map data providing service center via a network.

In the data processing device 2, as a processing function related to the present invention, the CPU 6 includes a map data management unit 61 for managing the vector map data 200 in the external storage device 1.
A map data operation unit 62 that performs an operation on vector map data in response to an input instruction from a user, a calculation conversion unit 63 that performs various arithmetic processes when performing coordinate conversion, scale change, and the like; A reference region setting unit 64 for setting a reference region in the system, and a display determining unit 6 for determining whether to display vector map data to be displayed normally or simply.
5 and a map data display processing unit 66 for displaying vector map data on the display 3 based on the determination of the display determination unit 65.
Is provided. Actually, these processing units are realized by loading a program for executing the processing function into the memory 7 in advance and executing the program by the hardware of the CPU 6. In the memory 7, the above-mentioned program, a coordinate conversion ratio 71 described later, a reference area 72 of the apparatus coordinate system, and a reference area (indistinguishable area) 7 of the absolute coordinate system
3 and display control information 800 also described later.

FIG. 2 shows a specific configuration example of the vector map data 200 in the external storage device 1. The vector map data 200 is defined in an absolute coordinate system, and one record is composed of a data type 201, an identification number 202, and an existence area 20.
3, data items such as start point coordinate value 204 and type configuration data 205. The existence area 203 is a circumscribed rectangle that includes vector map data adjacent thereto, so that vector map data having various shapes can be treated as a rectangle having a simple shape. The start point coordinate value 204 is the coordinates of the start point of the existence area 203 in the absolute coordinate system. The type configuration data 205 is a data item provided corresponding to the type 201. If the type 201 is "character", the character size and the number of characters. If so, the number of components is listed as an item. In the example of FIG. 2, the starting point coordinate value 204 is held so that it can be used for a graphic picking process and the like, and the type configuration data 205 and the like are provided as detailed data items of the vector map data.
It may be just the size of 03. In the present embodiment,
The units of numbers used for coordinates and the like are all millimeters (mm).

FIG. 3 shows, as an example, the identification numbers 1001, 1002, and 200 of the vector map data shown in FIG.
FIG. 1 is a diagram showing an image of data 1,3001. Each data is represented by an absolute coordinate which is a coordinate given to a fixed origin in an absolute coordinate system which is a coordinate system for expressing the vector map data itself. The absolute coordinates do not change whatever scale is displayed on the display. In FIG. 3, for example,
The “flower” 1001 has coordinates (45) in the absolute coordinate system.
0, 200) as the starting point, and the existence area is 1000 × 10
00 is defined by the rectangle. Similarly, the “bird” 1002 is defined as a 450 × 450 rectangle starting from the coordinates (1800, 3500) in the absolute coordinate system. In addition, the “circle” 2001 and the “building” 3001 are all defined by simple rectangular existence areas.

FIG. 4 shows a flowchart of one embodiment of the map data display processing according to the present invention. Hereinafter, the operation in the data processing device 2 of FIG. 1 will be described with reference to FIG.

The user inputs a scale change request using the keyboard 4 or the mouse 5 while viewing the map display screen on the display 3. In the data processing device 2, the map data operation processing unit 62 determines whether or not there is a scale change request by an operation such as enlargement / reduction of the user (step 401), and if there is no request, the process ends.

When a user requests a change in scale, first,
The calculation conversion unit 63 calculates the conversion ratio between the absolute coordinate system and the device coordinate system from the relationship between the display area of the vector map data in the absolute coordinate system and the display area of the display 3 in the device coordinate system (step 402). . The calculated conversion ratio (coordinate conversion ratio) is stored in the memory 7.

The device coordinates are coordinate systems of hardware devices constituting the system, and the display 3 has a coordinate system in units of pixels. That is, the user's operation on the map data displayed on the display 3 is an operation on the map data displayed on the device coordinate system. In the present embodiment, the vector map data to be displayed is displayed on the display 3 at a reduced scale of 500 mm / Pixel. Therefore, in step 402,
The conversion ratio between the absolute coordinate system and the device coordinate system is 500 mm /
Pixel is calculated.

Since the absolute coordinate system and the apparatus coordinate system have the above-described correspondence, the user can use the display 3.
If an operation such as enlargement / reduction is performed on, the conversion ratio will of course change.

Next, the reference area setting section 64 sets a reference area in the apparatus coordinate system and stores it in the memory 7 (step 4).
03). The reference area is an area serving as a reference when the vector map data is simply displayed. The reference region in the device coordinate system is a display range of the device coordinate system in which it is determined that the user cannot confirm the shape of the figure. In the present embodiment, the vector map data displayed smaller than the reference region is It is a target of simplified display.

Normally, even if vector graphic data is displayed with one pixel or less in the apparatus coordinate system, it cannot be discriminated from the user. Therefore, in the present embodiment, the reference area setting unit 64 sets the reference area in the apparatus coordinate system as one pixel, and sets vector map data whose size after the coordinate conversion is smaller than that as a target for simplified display.

Next, the calculation conversion unit 63 executes step 402
The reference area in the absolute coordinate system is calculated from the conversion ratio calculated in step 403 and the reference area set in step 403, and the calculated area is stored in the memory 7 (step 404). In other words, even if it is displayed on the display 3, the area of the apparatus coordinate system (1 pixel in this case) of the vector map data which cannot be distinguished by the user is converted into the absolute coordinate system, and the reference area in the absolute coordinate system obtained therefrom is converted. It is calculated in advance as an indistinguishable area. In the example, since the conversion ratio between the absolute coordinate system and the device coordinate system is 500 mm / Pixel, and the reference region in the device coordinate system is one pixel, the reference region (indistinguishable region) in the absolute coordinate system is 500 mm.

Thereafter, the map data operation processing unit 62 acquires one record of the vector map data to be displayed from the external storage device 1 (step 405), and the display determination unit 65 determines whether the vector map data exists in the absolute coordinate system. A determination process is performed to compare the size of the region with the indistinguishable region calculated in step 44 (step 406). In the present embodiment, in this determination process, the sizes of the respective regions in the X-axis and Y-axis directions are compared, and for example, if the indeterminate region is determined to be larger in either one, the indeterminate region Is larger than the existing area of the vector map data.

If the display determination section 65 determines in step 406 that the existing area is smaller than the indistinguishable area, the map data display processing section 62 performs a simplified display process on the vector map data (for example, thinning is performed. Do not display),
It returns to step 405 (step 407). For example, in FIG. 3, the existence area of the vector map data “bird” 1002 is 450 mm in both the X-axis and Y-axis directions, and is smaller than the indistinguishable area of 500 mm in any case.
It is the target of simplified display and is not displayed.

On the other hand, if the display determination unit 65 determines in step 406 that the area where the vector map data is present is larger than the indistinguishable area, the map data display processing unit 62 converts the vector map data into absolute data based on the conversion ratio. A coordinate conversion process for converting coordinates into device coordinates is performed (step 40).
8) The vector map data after the coordinate conversion is drawn and displayed on the display 3 (step 409). In the present embodiment, since the minimum display unit is 1 Pixel, a fraction generated after the coordinate conversion is truncated and displayed. For example, in FIG. 3, the existence area of the vector map data “flower” 1001 is 100
0 mm, which is larger than the indistinguishable area of 500 mm. Since the conversion ratio is 500 mm / Pixel,
Each existing area of 1000 m in the X-axis and Y-axis directions in the absolute display system
m is converted into 2 pixels in the device coordinate system, and is displayed on the display 3.

FIG. 5 shows the result of the above display processing. Here, the “bird” 1002 is not displayed because it has been subjected to the simplified display, but one “flower” 1001 is 2
It is drawn on the display 3 in Pixel.

When the processes of steps 405 to 409 are repeated until there is no more vector map data to be displayed, all the processes are completed (step 410).

In the above embodiment, the reference area setting section 64 automatically sets the reference area in the apparatus coordinate system (1 Pixel in the example), but the user can arbitrarily input the reference area from the input device such as the keyboard 4 and the mouse 5. You can also set a value. FIG. 6 is a flowchart of the processing, and FIG. 7 is a screen transition of the reference area setting at that time.

First, an instruction screen for setting a reference region is displayed on the display 3 so as to overlap the currently displayed map data (step 601). Reference numeral 701 in FIG. 7 is an example of the instruction screen. Here, if the user presses the “NO” button, the user does not set the reference area, but if the user presses the “YES” button, the reference area setting screen is displayed, The user can input an arbitrary size and rectangular shape (steps 602 and 603). Reference numerals 702 and 703 in FIG. 7 are examples of the setting screen. here,
Reference numeral 702 denotes a reference area setting screen by inputting a numerical value from the keyboard 4, and the user sets the vertical (Y) and horizontal (X) sizes of an arbitrary reference area in the apparatus coordinate system. Similarly, 7
Reference numeral 03 denotes a reference area setting screen by a rectangular input from the mouse 5. The user sets a desired reference area while checking the shape and size on the display 3. When the reference area input by the user is obtained (step 604),
A confirmation screen is displayed (step 605). 704 in FIG.
Is an example of the confirmation screen. After confirmation with the user (step 606), the input reference area is stored in the memory 7 (step 607). Thus, from the next processing, the reference area setting unit 64 retains the reference area in the device coordinate system designated by the user in step 403 of FIG.
To set. In step 606,
If the user presses the “redo” button, the process returns to step 603, and the reference area setting screen is displayed again.

Next, in FIG. 1, when the display judging section 65 judges that the existing area of the vector map data is smaller than the indistinguishable area, the simplified display processing in the map data display processing section 66 (step in FIG. 4). 407) Another embodiment will be described.

In the above-described embodiment, when the vector map data is displayed in a simplified manner, as in the case of the “bird” 1002, the data is uniformly thinned out and not displayed at all. Not exclusively. Further, the simplified display is uniformly performed irrespective of the type of the vector graphic data. However, all the map data need not always be the target of the simplified display. The embodiment described below uses a memory 7 in advance.
By storing the display control information 800 in the storage device, the form and the target of the simplified display are changed.

FIG. 8 shows display control information 800 in the memory 7.
It is a figure showing an example of. In the present embodiment, the display control information 800 is composed of display determination information 802 as a criterion for determining whether or not to perform simple display, and display mode information 803 indicating a display mode when performing simple display. It is determined for each type 801 of map data. In the display determination information 802, “not simplified display” means that the vector map data is displayed at a normal scale regardless of the scale. Further, “both X and Y are smaller than the reference area” means that the presence area of the vector map data to be displayed is both vertical (Y) and horizontal (X) in the determination processing in step 406 of FIG. If it is smaller than this, it indicates whether or not simplified display is to be performed. According to FIG. 8, only “expressway” is always displayed at the normal scale without being simply displayed, and other types of data are simply displayed. Is displayed. "One of X and Y is smaller than the reference area" means that one of the vertical (Y) and the horizontal (X) is larger than that of the reference area, but the other is smaller than the reference area. Only the "character" and the "city name" are also subjected to the simplified display in this case. The display mode information 803 indicates the display mode of the vector map data that is simply displayed. However, the ones that are marked “○” in “non-display” indicate that the display is thinned out and not displayed at all. The “alternative display” is a display in which the vector map data is replaced with simple symbols and characters, and is specifically displayed with a symbol defined by the “alternative display symbol”.

FIG. 9 is a flowchart of a simplified display process (step 407 in FIG. 4) when the display control information 800 is used. When the display determining unit 65 determines that the existing area of the vector map data is smaller than the indistinguishable area (step 406 in FIG. 4), the map data display processing unit 66 searches the display control information 800 in the present embodiment. Then, the display determination information and the display mode information of the type corresponding to the type of the vector map data are acquired (step 902). Then, based on the display determination information, the vector map data of the type has an existence area smaller in both X and Y than the reference area, or only one of them is smaller than the reference area.
It is checked whether or not the data is the target data for which the simplified display is to be classified (step 903). Here, it is assumed that the vector map data is a target for which the simplified display is not distinguished in both the X and Y directions or the size of one of the existing areas. Based on the display determination information, it is determined whether or not the vector map data is a target for simple display (step 90).
4) If it is not a simple display target (for example, an expressway), it is displayed on a normal scale (step 905). Also,
For simple display targets (e.g., letters, municipalities)
Further, it is determined whether or not it is an alternative display target based on the display mode information (step 906).
(Characters), thinned out and no display is performed (step 90)
7) If it is an alternative display target (for example, a municipal name), it is displayed with the alternative display symbol specified by the display mode information (step 908). Note that in step 903, it is also determined that both the existing regions X and Y of the vector map data are smaller than the reference region, or that one of X and Y is smaller than the reference region, and that it is determined that the simplified display is to be separated. For example, a circle,
Similarly, normal display, non-display, or alternative display can be performed based on the display determination information and the display mode information.

FIGS. 10 and 11 show specific display examples of this embodiment. FIG. 10 shows a scale of 50 mm / Pix.
11 is 100 mm / Pixel in FIG.
It is a case where it is set to 1.

In FIG. 10, six vector map data of 500 × 1500 (mm) are all imaged in the absolute coordinate system 1100.
1, a municipal name 1102, a circle 1103, a building 1104, a folding line 1105, and an expressway 1106 are defined. When these are converted and displayed on the device coordinate system at a reduced scale of 50 mm / Pixel, the size becomes 10 × 30 (Pixel).
X20 (Pixel), so that the indistinguishable area 1140 is 1000 × 1000 in the absolute coordinate system.
(Mm). Here, the absolute coordinate system 110
The relationship between the vector map data of 0 and the indistinguishable area 1140 corresponds to “one of X and Y is smaller than the reference area” of the display determination information 802 in FIG. In this case, display mode information 8
03 is the result of simple display processing performed on the device coordinate system 1
It is shown at 110. That is, the character 1111 is "non-display", and the municipal name 1112 is "alternative display" with the simple symbol "@". Also, circle 1113, building 11
14, the folding line 1115, and the highway 1116 are displayed as "not simplified display", so they are converted at a normal scale of 50 mm / Pixel and displayed in the device coordinate system 1110 at 10 × 30 (Pixel).

Similarly, in FIG. 11, the vector map data of 1101 to 1106 of the absolute coordinate system 1100 is 100 mm.
5x when converted and displayed on the device coordinate system at the scale of / Pixel
Although the size is 15 (Pixel), the reference area 1130 is defined as 20 × 20 (Pixel) in the absolute coordinate system, and therefore, the indistinguishable area 11 is not defined in the absolute coordinate system.
50 is set at 2000 × 2000 (mm).
Here, the relationship between the vector map data of the absolute coordinate system 1100 and the indistinguishable area 1150 is represented by the display determination information 8 shown in FIG.
02, “X and Y are both smaller than the reference area”.
In this case, the result of performing the simplified display processing based on the display mode information 703 is shown in the device coordinate system 1120, and the parts other than the expressway 1126 are simply displayed. For example, the character 1121, the building 1124, and the folding line 1125 are “non-display”, the municipal name 1122 is “△”, and the circle 1123 is “●”.
Instead of the symbol.

The embodiment of the present invention has been described above. Here, the logical algorithm of the processing flowchart as shown in FIGS. 4, 6, and 9 is described in a computer-executable language, and is, for example, a computer-readable recording medium, such as a map data display processing program. It can be provided by recording it on a floppy (registered trademark) disk, CD-ROM, memory card, or the like.
By loading this into a computer, the processing units 61 to 66 shown in FIG. 1 are constructed in cooperation with the hardware of the CPU 6.

[0041]

As described above, according to the present invention,
Since vector map data for performing coordinate conversion and display processing can be reduced, overall display processing can be speeded up. In addition, the user can arbitrarily set a reference area for performing the simplified display, and can freely set information such as a display mode, so that a display process more suited to the user's needs can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a map display processing system to which the present invention is applied.

FIG. 2 is a diagram illustrating a detailed configuration example of vector map data.

FIG. 3 is a diagram in which vector map data is imaged.

FIG. 4 is a flowchart of one embodiment of a map data display process according to the present invention.

FIG. 5 is a diagram showing an image when vector map data is displayed on a display at a reduced scale in one embodiment of the present invention.

FIG. 6 is a flowchart when a user sets a reference area.

FIG. 7 is a diagram illustrating a specific example in which a user sets a reference area.

FIG. 8 is a diagram showing a specific example of display control information.

FIG. 9 is a flowchart of a simplified display process based on display control information.

FIG. 10 is a diagram showing a specific example of simplified display based on display control information.

FIG. 11 is a diagram showing another specific example of simplified display based on the display control information.

FIG. 12 is a diagram showing an example of a case in which vector map data is subjected to continuous reduction processing according to the related art.

[Explanation of symbols]

 Reference Signs List 1 external storage device 2 data processing device 3 display 4 keyboard 5 mouse 6 central processing unit (CPU) 61 map data management unit 62 map data operation processing unit 63 calculation conversion unit 64 reference area setting unit 65 display determination unit 66 map data display processing Part 7 Memory 71 Conversion ratio 72 Reference area of device coordinate system 73 Reference area of absolute coordinate system (indistinguishable area) 200 Vector map data 800 Display control information

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C032 HC24 HC30 5B050 AA01 BA17 CA07 EA12 FA02 FA05 FA12 FA19 5B075 ND06 PP02 PP03 PQ02 PQ12 PQ48 UU13 5C082 AA01 AA22 AA24 AA36 AA37 BA12 BB01 CA02 CA36 CA33 CA06 MM08

Claims (4)

[Claims] In a map data display processing method for displaying map data at a reduced scale, a coordinate conversion ratio between a device coordinate system and an absolute coordinate system is calculated, and a range of an area for simplified display in the device coordinate system is indicated. A reference area is set, and a reference area in an absolute coordinate system is calculated based on the reference area in the apparatus coordinate system and the coordinate conversion ratio as an indistinguishable area. Existence of map data expressed in an absolute coordinate system Comparing the area with the indistinguishable area, performing a normal scale change display process when the map data is larger, and performing a simplified display process when the map data is smaller. Map data display processing method. 2. The map data display processing method according to claim 1, wherein a numerical value or an area input by a user is set as the reference area in the apparatus coordinate system. 3. The map data display processing method according to claim 1, wherein, for each type of map data, display determination information indicating a criterion as to whether or not to perform simplified display and a display mode for simplified display. A vector map data display processing method, comprising preparing display control information including display mode information, and executing a simplified display process based on the display control information during the simplified display process. 4. A map data display processing device for displaying map data at a reduced scale, means for storing map data expressed in an absolute coordinate system, and calculating a coordinate conversion ratio between the device coordinate system and the absolute coordinate system. Means for setting a reference area indicating a range of an area for simplified display in the apparatus coordinate system, and a reference area in the absolute coordinate system based on the reference area in the apparatus coordinate system and the coordinate conversion ratio. Means for calculating and setting as an indistinguishable area; means for comparing an existing area of the map data expressed in the absolute coordinate system with the indistinguishable area; and an existing area of the map data being larger than the indistinguishable area. Means for converting the map data into a device coordinate system based on the coordinate conversion ratio and displaying the map data; and, when an existing area of the map data is smaller than the indistinguishable area, Vector map data display processing apparatus, characterized by obtaining and means for display brief.