JP2007264474A - Display controller, display control method, display control program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display controller, a display control method, a display control program and a recording medium which can display map data smoothly. <P>SOLUTION: A setup section 101 of the display controller 100 sets a display scale of the map data on a display screen 110. A determination section 102 determines characters for display used to display the map data based upon the display scale set by the setting section 101. A data acquisition section 103 acquires scalable font data of the characters for display determined by the determination section 102 prior to the display of the map data. A conversion unit 104 converts the scalable font data acquired by the data acquisition section 103 into bit map data. A display control section 105 displays the characters for display converted into the bit map data by the conversion section 104 on the display screen 110 together with the map data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display control device that controls display of map data, a display control method, a display control program, and a recording medium. However, use of the present invention is not limited to the above-described display control device, display control method, display control program, and recording medium.

  Conventionally, in navigation devices that perform route guidance to a destination point, it is known to use scalable font data that expresses the outer circumference of characters as vectors as font data used for place name display in map data and character display on the operation menu screen. ing. The scalable font data needs to be expanded into bitmap data when the character string is displayed on the display.

  For this reason, bitmap font data corresponding to frequently used characters included in map data is stored in advance in the bitmap font area of the font memory, and the font processing unit uses a map drawing processing unit or the like to store the character code. When bitmap font data corresponding to this character code is stored in the font memory when specified, this bitmap font data is read. If not, scalable font corresponding to this character code is read. There has been proposed a navigation device that performs processing of reading data and developing it into bitmap font data (see, for example, Patent Document 1 below).

JP 2005-009936 A

  However, according to the above-described prior art, there is a problem that the change of the display character string by the display scale is not taken into consideration. Even for map data centered on the same point, the place names to be displayed differ depending on the display scale. For example, if the map is a wide area map, the name of the prefecture, the scale of 1 / 3,000, or the like, and if it is a map around the current position of the vehicle, the lot number and the name of the surrounding facility are displayed. When all such characters are expanded, characters that are not used are expanded into bitmap data, and the problem that the memory area is wasted is given as an example.

  In addition, when the vehicle moves for a long time, the character used for the map display in the vicinity is changed, and therefore, the problem that the expansion processing from the scalable font data to the bitmap data has to be performed again is given as an example.

  In order to solve the above-described problems and achieve the object, the display control apparatus according to the first aspect of the present invention includes a setting means for setting a display scale of map data on a display screen, and a display scale set by the setting means. And determining the character used for displaying the map data (hereinafter referred to as display character) and the scalable font data of the display character determined by the determining unit prior to the display of the map data. The data acquisition means to acquire, the conversion means for converting the scalable font data acquired by the data acquisition means to bitmap data, and the display character converted to bitmap data by the conversion means, the map data And a display control means for displaying on the display screen.

  A display control method according to the invention of claim 6 is used for displaying the map data based on a setting step of setting a display scale of map data on a display screen and the display scale set in the setting step. A determination step of determining characters (hereinafter referred to as display characters), a data acquisition step of acquiring scalable font data of the display characters determined in the determination step prior to display of the map data, and the data acquisition A conversion step of converting the scalable font data acquired in the step into bitmap data, and a display control step of displaying the display characters converted into the bitmap data in the conversion step on the display screen together with the map data; , Including.

  A display control program according to a seventh aspect of the invention causes a computer to execute the display control method according to the sixth aspect.

  A recording medium according to an eighth aspect of the present invention is readable by a computer that records the display control program according to the seventh aspect.

  Exemplary embodiments of a display control device, a display control method, a display control program, and a recording medium according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
First, the functional configuration of the display control apparatus 100 according to the embodiment will be described. FIG. 1 is a block diagram illustrating a functional configuration of the display control apparatus. The display control apparatus 100 includes a setting unit 101, a determination unit 102, a data acquisition unit 103, a conversion unit 104, a display control unit 105, a position information acquisition unit 106, and a route information acquisition unit 107.

  The setting unit 101 sets the display scale of map data on the display screen 110. The display scale of the map data is a ratio between the distance on the map data and the actual distance on the ground surface, and is expressed as, for example, 1 / 10,000 or 1 / 3,000. In the case of the 1 / 3,000 scale, 1 cm on the map data corresponds to 3000 cm (30 m) on the actual ground surface. The scale setting is performed by, for example, setting input by the user or automatic setting change accompanying execution of other functions (for example, route guidance function).

  Based on the display scale set by the setting unit 101, the determining unit 102 determines a character (hereinafter referred to as a display character) used for displaying map data. The determination part 102 determines the character which comprises the administrative division name displayed on map data, and the character which comprises the facility name displayed on map data as a display character, for example.

  In addition, for example, when displaying a wide area map, the determination unit 102 determines the characters constituting the prefecture name as display characters, and the characters constituting the city name, area name, lot number, etc. as the scale becomes smaller Is determined as a display character.

  The data acquisition unit 103 acquires scalable font data of display characters determined by the determination unit 102 prior to display of map data. The data acquisition unit 103 acquires scalable font data from a storage medium having a large storage capacity such as a hard disk onto a memory that can be accessed at high speed.

  The conversion unit 104 converts the scalable font data acquired by the data acquisition unit 103 into bitmap data.

  The display control unit 105 causes the display screen 110 to display the display characters converted into the bitmap data by the conversion unit 104 together with the map data. For example, the display control unit 105 displays bitmap data of a character string such as a place name corresponding to the position on image data indicating a road shape.

  The position information acquisition unit 106 acquires current position information of the moving object. The current position information is information that specifies the current position of the moving body as one point on the map data, such as latitude and longitude. Further, the position information acquisition unit 106 may continuously acquire the current position information as the moving body moves.

  When the current position information is acquired by the position information acquisition unit 106, the data acquisition unit 103 acquires scalable font data that is used to display map data within a predetermined range including the current position of the moving object. In addition, for example, the determination unit 102 may determine a character used for display of map data within a predetermined range including the current position of the moving object as a display character.

  The route information acquisition unit 107 acquires the movement route information of the moving object. The movement route information is information for specifying a movement route to the moving destination point of the moving body. When the travel route information is obtained by the route information obtaining unit 107, the data obtaining unit 103 obtains scalable font data that is used for displaying map data within a predetermined range along the travel route of the moving object. In addition, for example, the determining unit 102 may determine a character used for displaying map data within a predetermined range along the moving path of the moving object as a display character.

  Next, display control processing by the display control apparatus 100 will be described. FIG. 2 is a flowchart illustrating a procedure of display control processing by the display control device. In the flowchart of FIG. 2, the display control apparatus 100 first sets the display scale of the map data by the setting unit 101 (step S201).

  Next, the determination unit 102 determines characters to be used for displaying the map data based on the display scale of the map data (step S202). Subsequently, prior to display of map data, the data acquisition unit 103 acquires scalable font data of display characters (step S203), and the conversion unit 104 converts it into bitmap data (step S204). When the current position information of the moving object is acquired by the position information acquisition unit 106 or when the movement route information of the moving object is acquired by the route information acquisition unit 107, the data acquisition unit 103 It is also possible to acquire scalable font data used for displaying map data within a predetermined range from the current position or moving route.

  Then, the display control unit 105 displays the display characters converted into the bitmap data together with the map data on the display screen (step S205), and the processing according to this flowchart ends.

  As described above, according to the display control apparatus 100, display characters are determined based on the display scale of the map data. Thereby, only the characters necessary for the display of the map data can be acquired from the scalable font data, and the resource of the display control apparatus 100, specifically the memory consumed when acquiring the scalable font data. Etc. can be reduced.

  Further, according to the display control apparatus 100, prior to display of map data, scalable font data of display characters is acquired in advance and converted into bitmap data. Thereby, the processing load in the display process of map data can be reduced, and map data can be displayed quickly.

  Further, among the scalable font data, data used for displaying map data within a predetermined range including the current position of the moving object and data used for displaying map data within a predetermined range along the moving path of the moving object are acquired. . Thereby, only the characters necessary for the display of the map data can be acquired from the scalable font data, and the resource of the display control apparatus 100, specifically the memory consumed when acquiring the scalable font data. Etc. can be reduced.

  Note that bitmap data may be stored in advance for characters used to display a predetermined scale in the map data display scale. For example, bitmap data is stored in advance for a frequently used standard scale. Thereby, when displaying map data with a predetermined scale, it is not necessary to perform conversion processing from scalable font data to bitmap data, and the display speed can be improved.

  In addition, once created bitmap data, even if the map data display scale is changed, it is not deleted immediately, and it is retained within a range that does not exceed the predetermined storage capacity for character data. It is good also as holding. Thereby, when returning to the original display scale, since it is not necessary to perform the conversion process from scalable font data to bitmap data, the display speed can be improved.

  In addition, when creating bitmap data, first, only the characters necessary for the map display around the current position of the moving object are converted into bitmap data, and other characters are sequentially converted into bitmap data while displaying the map. It is good to do. As described above, by performing the map display process and the conversion process in parallel, even when there is a large amount of character data to be converted, the map display can be performed quickly.

  Next, examples of the display control apparatus 100 according to the above-described embodiment will be described. In the following embodiments, a case where the display control device 100 is applied to a navigation device 300 mounted on a vehicle will be described.

(Hardware configuration of navigation device 300)
Next, the hardware configuration of the navigation device 300 will be described. FIG. 3 is a block diagram illustrating a hardware configuration of the navigation apparatus. In FIG. 3, the navigation apparatus 300 includes a CPU 301, a ROM 302, a RAM (memory) 303, a magnetic disk drive 304, a magnetic disk 305, an optical disk drive 306, an optical disk 307, and an audio I / F (interface) 308. , Microphone 309, speaker 310, input device 311, video I / F 312, camera 313, display 314, communication I / F 315, GPS unit 316, various sensors 317, and external connection I / F F318. Each component 301 to 318 is connected by a bus 320.

  First, the CPU 301 governs overall control of the navigation device 300. The ROM 302 records programs such as a boot program, a communication program, a database creation program, and a data analysis program. The RAM 303 is used as a work area for the CPU 301.

  The magnetic disk drive 304 controls the reading / writing of the data with respect to the magnetic disk 305 according to control of CPU301. The magnetic disk 305 records data written under the control of the magnetic disk drive 304. As the magnetic disk 305, for example, an HD (hard disk) or an FD (flexible disk) can be used.

  The optical disk drive 306 controls the reading / writing of the data with respect to the optical disk 307 according to control of CPU301. The optical disk 307 is a detachable recording medium from which data is read according to the control of the optical disk drive 306. As the optical disc 307, a writable recording medium can be used. In addition to the optical disk 307, the removable recording medium may be an MO, a memory card, or the like.

  One example of information recorded on the magnetic disk 305 or the optical disk 307 is map data used for route search / route guidance. The map data includes background data representing features (features) such as buildings, rivers, and the ground surface, and road shape data representing the shape of the road. The map data can be displayed two-dimensionally or three-dimensionally on the display screen of the display 314. Drawn. When the navigation device 300 is guiding a route, the map data and the current position of the vehicle acquired by the GPS unit 316 described later are displayed in an overlapping manner.

  In addition, on the magnetic disk 305 or the optical disk 307, scalable font data necessary for displaying characters such as city names and road names included in the map data and menu screen characters used for various operations and settings. Is stored. The scalable font data is font data that retains the shape of the character as vector information of the outer peripheral line, and when the character is output, it is converted into bitmap data corresponding to the resolution of the display 314 to be described later and output.

  FIG. 4 is an explanatory diagram for explaining the character display by the scalable font data. FIG. 5 is an explanatory diagram for explaining character display using bitmap data. FIG. 4 shows a character S displayed in a scalable font. On the other hand, FIG. 5 shows a character B displayed by bitmap data.

  The character S shown in FIG. 4 is expressed by curve data (vector data) taking the outline (outline) and center line of the character, and jaggy (jagged edges) and disappearance of strokes may occur even if the size is changed. Smooth character display can be performed. On the other hand, since the character B shown in FIG. 5 is expressed as a collection of points for each pixel, enlarging or reducing the scale causes jaggies and the like, and font data is stored for each character size to be displayed. It is necessary to keep it.

  For this reason, the navigation device 300 stores font data as scalable font data, converts characters necessary for display into bitmap data, and displays them on the display 314.

  Returning to the description of FIG. 3, the audio I / F 308 is connected to a microphone 309 for audio input and a speaker 310 for audio output. The sound received by the microphone 309 is A / D converted in the sound I / F 308. In addition, sound is output from the speaker 310. Note that the sound input from the microphone 309 can be recorded on the magnetic disk 305 or the optical disk 307 as sound data.

  Examples of the input device 311 include a remote controller having a plurality of keys for inputting characters, numerical values, various instructions, a keyboard, a mouse, a touch panel, and the like. Further, the input device 311 can be connected to another information processing terminal such as a digital camera or a mobile phone terminal to input / output data.

  The video I / F 312 is connected to a camera 313 for video input and a display 314 for video output. Specifically, the video I / F 312 includes, for example, a graphic controller that controls the entire display 314, a buffer memory such as a VRAM (Video RAM) that temporarily records image information that can be displayed immediately, and a graphic controller. Based on the output image data, the display 314 is configured by a control IC or the like.

  The camera 313 captures images inside and outside the vehicle and outputs them as image data. An image captured by the camera 313 can be recorded on the magnetic disk 305 or the optical disk 307 as image data. The display 314 displays icons, cursors, menus, windows, or various data such as characters and images. As the display 314, for example, a CRT, a TFT liquid crystal display, a plasma display, or the like can be adopted.

  The communication I / F 315 is connected to a communication network such as the Internet via wireless and functions as an interface between the communication network and the CPU 301. Communication networks include LANs, WANs, public line networks and mobile phone networks.

  The GPS unit 316 receives radio waves from GPS satellites and outputs information indicating the current position of the vehicle (current position of the navigation device 300). The output information of the GPS unit 316 is used when the CPU 301 calculates the current position of the vehicle together with output values of various sensors 317 described later. The information indicating the current position is information for specifying one point on the map data, such as latitude / longitude and altitude.

  The various sensors 317 output information that can determine the position and behavior of the vehicle, such as a vehicle speed sensor, an acceleration sensor, and an angular velocity sensor. The output values of the various sensors 317 are used for the calculation of the current position by the CPU 301 and the measurement of the change in speed and direction.

  Various sensors 317 detect vibrations generated in the vehicle. For vibration detection, a vibration detection sensor may be provided, or vibration generated in the vehicle may be detected from information output from the acceleration sensor.

  The external connection I / F 318 is an interface for connecting to an external device such as an audio device or a vehicle air conditioner. The external connection I / F 318 includes, for example, a dedicated connection cable port, an infrared communication port, and the like.

  In the configuration of the display control apparatus 100 according to the embodiment, the setting unit 101 is the input device 311, the determination unit 102 and the conversion unit 104 are the CPU 301, the data acquisition unit 103 is the magnetic disk drive 304, the magnetic disk 305, and the optical disk drive. The display control unit 105 implements the functions of the CPU 301, the video I / F 312, the position information acquisition unit 106, and the route information acquisition unit 107 by the CPU 301, the GPS unit 316, and various sensors 317.

(Map data display control processing by the navigation device 300)
Next, map data display control processing by the navigation device 300 will be described. As described above, the navigation apparatus 300 stores font data used for displaying characters as scalable font data, converts characters necessary for display into bitmap data, and displays the converted data on the display 314.

  On the other hand, the conversion processing from scalable font data to bitmap data uses the resources of the CPU 301, which may impose a processing load on the CPU 301. For this reason, the navigation apparatus 300 determines the display character used for display of map data prior to display of map data. Then, scalable font data of display characters is read from the magnetic disk 305 or the optical disk 307, converted into bitmap data, and stored in the RAM 303. Thereby, the processing load of CPU301 at the time of map data display can be reduced.

  The display characters are determined according to the display scale of the map data. Therefore, only the characters necessary for display can be determined as display characters, and the area of the RAM 303 can be used effectively.

  FIG. 6 is a flowchart showing the procedure of map data display control processing by the navigation device. In the flowchart of FIG. 6, the CPU 301 of the navigation device 300 first obtains the setting information of the display scale of the map data on the display 314 (step S601). The display scale setting information is information indicating the scale of the map data such as “1 / 3,000” or “1 / 10,000”.

  Next, the CPU 301 extracts display characters according to the display scale of the map data based on the setting information acquired in step S601 (step S602). For example, when the wide area map is set as the display scale, the CPU 301 extracts characters constituting the prefecture name as display characters. In addition, as the scale is reduced, characters constituting a city name, a district name, a lot number, and the like, and characters constituting the names of surrounding facilities are extracted as display characters.

  Subsequently, the CPU 301 reads scalable font data of display characters from the magnetic disk 305 or the optical disk 307 (step S603), and converts it into bitmap data (step S604). Then, the display character converted into the bitmap data is stored in the RAM 303 (step S605).

  Note that the scalable font data read in step S603 is used to display map data within a predetermined range including the current position of the vehicle, and is used to display map data within a predetermined range along the moving route of the vehicle. May be. Further, the extraction process in step S602 is limited to the one used for displaying map data within a predetermined range including the current position of the vehicle and the one used for displaying map data within a predetermined range along the moving route of the vehicle. May be.

  The CPU 301 waits until the vehicle starts to travel (step S606: No loop). When the vehicle starts traveling (step S606: Yes), the bitmap data stored in the RAM 303 is used to display the display 314. Map data is displayed (step S607). If the setting of the display scale of the display 314 is changed during traveling (step S608: Yes), the process returns to step S602, and display characters that match the display scale are extracted.

  If the setting of the display scale is not changed (step S608: No), the process returns to step S607 until the travel is finished (step S609: No), and the display of the map data using the bitmap data is continued. And when driving | running | working is complete | finished (step S609: Yes), the process by this flowchart is complete | finished.

  FIG. 7 is an explanatory diagram showing an example of display characters extracted in step S602 of FIG. FIG. 7 shows display characters 701 when the display scale is set to wide area display in descending order of scale, and display characters 702 and 1 / 75,000 when set to 1 / 300,000. The display character 703 when set to 1/8000, the display character 704 when set to 1/1000, and the display character 705 when set to 1/1000 are shown. . In the following example, a case where display characters are extracted centering on the Chiyoda Ward Office in Tokyo will be described.

  Prefecture characters such as “Tokyo”, “Saitama”, and “Chiba” are extracted as the display characters 701 when the wide-area display is set. In addition, the display characters 702 when set to 1 / 300,000 include main station names such as “Tokyo”, “Ueno”, and “Shinagawa”, and main features such as “Tokyo Bay” and “Tokyo Bay Aqua Line”. The name is extracted.

  In addition, the display character 703 when 1 / 755,000 is set includes the name of a municipality such as “Chiyoda Ward”, the names of surrounding stations such as “Tokyo”, “Yurakucho”, “Kanda”, and “Imperial Palace” The names of major features such as “Budokan” are extracted. The display character 704 when it is set to 1/8000 is extracted from the facility names with relatively high public interest, such as “Chiyoda Ward Office”, “Kitanomaru Park”, “Chidorigafuchi”, “XX Post Office”, etc. The

  In addition, the display character 705 when it is set to 1 / 3,000 includes facility names such as “Chiyoda Ward Office”, “Chiyoda Ward Public Hall”, “Kudan Joint Government Building”, “Kudan Minami 1”, “Kanda Jimbocho” Lot numbers such as “3” are also extracted.

  Thus, in the navigation apparatus 300, the display character extracted for every display scale is changed. Thereby, only the character used for the display of map data can be converted into bitmap data, and the storage area of the RAM 303 can be used effectively.

  As described above, according to the navigation device 300, the display character used for displaying the map data is determined based on the display scale of the map data. As a result, only the characters necessary for displaying the map data can be acquired from the scalable font data, and the storage area of the RAM 303 consumed when acquiring / converting the scalable font data can be reduced. .

  Further, according to the navigation device 300, prior to display of map data, scalable font data of display characters is acquired in advance and converted into bitmap data. Thereby, the processing load in the display process of map data can be reduced, and map data can be displayed quickly. In addition, other functions of the navigation device 300 such as route guidance processing and image processing can be executed smoothly.

  Furthermore, among the scalable font data, what is used to display map data within a predetermined range including the current position of the vehicle, and what is used to display map data within a predetermined range along the moving route of the vehicle Also good. As a result, only the characters necessary for displaying the map data can be acquired from the scalable font data, and the storage area of the RAM 303 consumed when acquiring / converting the scalable font data can be reduced. .

  Note that bitmap data may be stored in advance for characters used to display a predetermined scale in the map data display scale. For example, bitmap data is stored in advance for a frequently used standard scale. Thereby, when displaying map data with a predetermined scale, it is not necessary to perform conversion processing from scalable font data to bitmap data, and the display speed can be improved.

  In addition, once created bitmap data, even if the map data display scale is changed, it is not deleted immediately, and it is retained within a range that does not exceed the predetermined storage capacity for character data. It is good also as holding. Thereby, when returning to the original display scale, since it is not necessary to perform the conversion process from scalable font data to bitmap data, the display speed can be improved.

  In addition, when creating bitmap data, first, only the characters necessary for the map display around the current position of the moving object are converted into bitmap data, and other characters are sequentially converted into bitmap data while displaying the map. It is good to do. As described above, by performing the map display process and the conversion process in parallel, even when there is a large amount of character data to be converted, the map display can be performed quickly.

  The display control method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. The program may be a transmission medium that can be distributed via a network such as the Internet.

It is a block diagram which shows the functional structure of a display control apparatus. It is a flowchart which shows the procedure of the display control process by a display control apparatus. It is a block diagram which shows the hardware constitutions of a navigation apparatus. It is explanatory drawing for demonstrating the character display by scalable font data. It is explanatory drawing for demonstrating the character display by bitmap data. It is a flowchart which shows the procedure of the map data display control process by a navigation apparatus. It is explanatory drawing which shows an example of the character for a display extracted by step S602 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Display control apparatus 101 Setting part 102 Determination part 103 Data acquisition part 104 Conversion part 105 Display control part 106 Location information acquisition part 107 Path | route information acquisition part 110 Display screen

Claims (8)

Setting means for setting the display scale of the map data on the display screen;
Determining means for determining a character used for displaying the map data (hereinafter referred to as display character) based on the display scale set by the setting means;
Data acquisition means for acquiring scalable font data of display characters determined by the determination means prior to display of the map data;
Conversion means for converting the scalable font data acquired by the data acquisition means into bitmap data;
Display control means for displaying the display characters converted into bitmap data by the conversion means on the display screen together with the map data;
A display control apparatus comprising: The determining means includes
The display control apparatus according to claim 1, wherein a character constituting an administrative division name displayed on the map data is determined as the display character. The determining means includes
The display control apparatus according to claim 1 or 2, wherein a character constituting a facility name displayed on the map data is determined as the display character. Comprising position acquisition means for acquiring the current position information of the moving body
The data acquisition means includes
The display control according to claim 1, wherein the scalable font data is used to display the map data within a predetermined range including a current position of the moving body. apparatus. Provided with route information acquisition means for acquiring movement route information of a moving object,
The data acquisition means includes
The display according to any one of claims 1 to 4, wherein the scalable font data is used to display the map data within a predetermined range along a moving path of the moving body. Control device. A setting process for setting the display scale of the map data on the display screen;
A determination step of determining a character used for displaying the map data (hereinafter referred to as a display character) based on the display scale set in the setting step;
A data acquisition step of acquiring scalable font data of display characters determined in the determination step prior to display of the map data;
A conversion step of converting the scalable font data acquired in the data acquisition step into bitmap data;
A display control step of displaying the display characters converted into bitmap data in the conversion step on the display screen together with the map data;
The display control method characterized by including.   A display control program for causing a computer to execute the display control method according to claim 6.   A computer-readable recording medium on which the display control program according to claim 7 is recorded.

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