JP2006039486A - Map information processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a map information processor which easily extracts a map image formed along a user's route, as small maps and displays small maps on a mobile device, which the user carries, along the user's route without breaks. <P>SOLUTION: A map information processor 1 comprises a display capability setting means 100 for setting a display capability of the mobile device and an image compression system which can be decoded by the mobile device; a map information storage part 301 wherein the display capability and the image compression system set by the display capability setting means are stored; a map image forming means 104 for forming a map image being along the most suitable route from a start point to an end point; a map image dividing means 105 for dividing the map image in accordance with the display capability stored in the map information storage part to generate a plurality of small maps having congruent shapes; and a map image compression means 106 for referring to the image compression system stored in the map information storage part 301 to compress images of the small maps. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a map information processing apparatus that divides a map image formed by a car navigation apparatus or the like along a predetermined route and transmits the divided map image to a portable device for viewing the map image.

  2. Description of the Related Art In recent years, car navigation devices that search for an optimal route and perform guidance using map images, character information, and synthesized speech so as to follow the optimal route while positioning the current position have become widespread.

  In the search process of the optimum route in the car navigation apparatus, an operation is performed in which time, distance, cost, and the like are evaluation items and a route that minimizes these items is found. The Dijkstra method or an A algorithm improved from the Dijkstra method is used as a route search method (see Non-Patent Document 1).

  The guidance of the optimum route for the user is performed by displaying a map centered on the own vehicle on the display and by an arrow indicating the traveling direction, an instruction by synthetic voice, or the like. The map on the display scrolls up, down, left and right as the vehicle moves.

  In recent years, portable devices such as digital still cameras, digital video cameras, and mobile phones are equipped with an interface of a liquid crystal monitor and a memory card, and a still image recorded on the memory card is viewed on the liquid crystal monitor. It is possible. For this reason, as a result of route search with a car navigation device etc., a method of displaying a map with guidance information on the monitor of the portable device owned by the user while the user is walking or moving by train or bus is also developed. Has been. When displaying a map on this portable device, the monitor of the portable device is smaller than the monitor of the car navigation device, etc., so the base map displayed on the monitor of the car navigation device is divided into multiple small maps and displayed There is a need to.

In order to divide and display, a method has been proposed in which the entire map is divided into meshes, each small map is compressed, and each small map file name is given a name that can be calculated on the map. (See Patent Document 1).
"Navigation System" by Hiroaki Arai and Shoichi Kanno, Sankai-do Publishing July 31, 2001 JP 2001-142819 A

  When dividing and displaying a plurality of small maps, it is necessary to display the small maps adjacent to each other so as not to be interrupted. However, in the systems of Patent Document 1 and Non-Patent Document 1 described above, complicated program processing is required even when the names on the entire map are divided and the user's route is displayed. The tracking route was interrupted, and even if it was not interrupted, the route flew and it was difficult to see.

  According to the present invention, a small map extracted by a simpler method than a map image formed by a navigation device while a user is walking, moving by train or bus is taken along a user route on a monitor of a user portable device. Another object of the present invention is to provide a map information processing apparatus that can display without interruption.

  In view of the above problems, the feature of the present invention is that [a] a map information processing apparatus that generates a map image showing a route from a start point to an end point, and divides the map image and transmits the map image to the portable device (320). The display capability setting means (100) for setting the display size of the display unit provided in the portable device (320) and the type of the image compression method corresponding to the data decoding method of the portable device (320), and [b] display A map information storage unit (301) for storing the display size and the type of image compression method set by the capability setting means (100), and [c] forming a map image along the shortest time path from the start point to the end point. Map image forming means (104) and [d] Map image division for dividing the formed map image based on the display size stored in the map information storage unit (301) and generating a plurality of rectangular divided maps A map provided with a stage (105), and [e] image compression means (106) for respectively compressing a plurality of rectangular divided maps corresponding to the type of image compression method stored in the map information storage unit (301). The gist is that it is an information processing apparatus.

  Further, the present invention is characterized in that [f] the map image dividing means (105) divides the start point as the center point of the previous rectangular divided map; it matches the length of the short side or square of the rectangle of the previous rectangular divided map. In this case, the distance equal to or less than the distance corresponding to the length of one side is set as the dividing distance, and the distance along the route from the center point to the end point is set as the remaining distance; is the remaining distance equal to the dividing distance? Otherwise, the end point is divided as the center point of the previous rectangle division map; if the remaining distance is larger than the division distance, a point separated from the center point by the division distance along the route is a new rectangle division map. It may be added that a plurality of rectangular divided maps are generated by being divided as the center point of.

  According to the map information processing apparatus of the present invention, the user's tracking route is calculated by a simple algorithm so that it always becomes the center point of the small map where the current location of the user is divided, and the display capability of the user's portable device is obtained. At the same time, it can be extracted from the base map image and transmitted to the portable device. Thereby, in a portable device, a small map can be displayed along the user route and without interruption.

  As a division algorithm, a plurality of small maps centered on a point on a route for each distance corresponding to the short side of a rectangular small map are extracted from the base map.

  Hereinafter, a map information processing apparatus according to an embodiment of the present invention will be described. In addition, the apparatus, method, etc. which are used in embodiment of this invention are examples, and of course, this invention is not limited to these.

(Map information processing device)
As shown in FIG. 1, a map information processing apparatus 1 according to an embodiment of the present invention includes a central processing unit (hereinafter referred to as “CPU”) 300 having a high-performance processing capability for performing optimal route calculation and the like on a display. Map data to be displayed, map image information (see FIG. 3), map information storage unit 301 for storing map file information (see FIG. 4), ROM (read only memory) 302, RAM (random access memory) 303, position information GPS (Global Positioning System) 304 for obtaining, a sensor 305 such as acceleration, a display controller 306 for controlling a display for displaying map information and map images, a VRAM (video ram) 307, a display 308 such as a liquid crystal monitor, Touch panel and keyboard that accept input such as ground settings An input interface 310 composed of a network and a cable for receiving data input from the outside, an output interface 309 for transmitting a map image or the like to the user's portable device 320 via wired or wireless communication, and an internal connecting these devices The bus 311 is configured.

  The CPU 300 includes a display capability setting unit 100, a start point position setting unit 101, an end point position setting unit 102, an optimum route determining unit 103, a map image forming unit 104, a map image dividing unit 105, a map image compressing unit 106, as shown in FIG. Identification code adding means 107 and the like are provided. The map information processing program is executed by the CPU 300 appropriately calculating these modules.

  The display capability setting unit 100 sets map image information handled by the mobile device 320 according to information input via the input interface 310 or the like. As shown in FIG. 3, the map image information includes the screen size of the display 321 of the portable device 320, the compression method that can be handled, and the like. The starting point position setting unit 101 sets the current position acquired from the GPS 304 as the starting point of navigation. The end point position setting means 102 sets the navigation target position via the input interface 310 or the like.

  The optimum route determination unit 103 searches the map data in the map information storage unit 301 and sets, for example, the route with the shortest time as the optimum route. The map image forming unit 104 forms a map image showing a route to the destination on the map.

  The map image dividing unit 105 divides the screen along the optimum route according to the display capability of the display 321 of the mobile device 320. The map image compression means 106 compresses the image of the small map screen, which is a divided small rectangular divided map, by a method that can be expanded by the mobile device 320 so as to be suitable for communication and storage in the mobile device 320. The identification code adding means 107 adds sequential identification codes to the image of the small map so that the portable device 320 sequentially displays the screen along the optimum route. For example, when the file name is used as the identification code as shown in FIG. 4, the display order can be easily acquired by the serial number (map01 to map04) included in the file name.

(Operation of map information processing device)
Next, operation | movement of the map information processing apparatus 1 is demonstrated with reference to the flowchart of FIG.

(A) First, when the CPU 300 in FIG. 1 receives a map acquisition request from the user via the input interface 310 or the like, in step S100, the start point position setting unit 101 in FIG. 2 sends the current position information to the GPS 304 in FIG. Request detection. The GPS 304 calculates the current position from information such as latitude, longitude, and altitude, and delivers it to the starting point position setting means 101. The starting point position setting means 101 sets this current position as the starting point.

(B) In step S101, the end point position setting unit 102 in FIG. 2 prompts the user to input a position as the end point. When the user inputs destination information via an input interface 310 such as a keyboard or a touch panel on the display 308, the end point position setting unit 102 sets the destination information as the end point position. In step S102, the display capability setting means 100 determines the size of the display 321 of the portable device 320 to which the map data is transferred and the compression method (see FIG. 3) that can be handled, and an input interface such as a USB cable connected to the portable device 320. Set via 310 or the like. Note that the user may input manually via a keyboard or the like.

(C) In step S103, the optimum route determination unit 103 searches the map information storage unit 301 for the optimum route based on the set start point position and end point position. For route selection, the passage time of all routes that may pass from the start point position to the end point position is read, and the optimum route determination means 103 searches for the route with the shortest time as the optimum route, for example. In step S104, the route with the shortest time is set as the optimum route. As a route search algorithm, there are the Dijkstra method and an A algorithm obtained by improving the Dijkstra method.

(D) In step S <b> 105, the map image forming unit 104 reads map data around the optimum route from the map data in the map information storage unit 301. In step S106, the map image forming unit 104 forms a map image showing a route to the destination. This map image is displayed as shown in FIG. 6 as an example. In FIG. 6, A is the start point position, B is the end point position, and the dotted line written from A to E indicates the optimum route.

(E) In step S107, the map image dividing means 105 divides the map image along the optimum route according to the display capability of the display 321 of the portable device 320. This is because, in general, the display 308 of the mobile device 320 has a size of QVGA (quarter) compared to the display 308 of the map information processing apparatus 1 having VGA (video graphic array (registered trademark): 640 pixels × 480 pixels) or more. This is because the screen formed by the map information processing apparatus 1 cannot be displayed as it is. Details of this division processing will be described later.

  The map image is divided into small maps such as those shown in FIGS.

(F) In step S108, the map image compression means 106 compresses the image of the small map so as to be suitable for data communication and storage in the portable device 320. As an image compression method, JPEG (Joint Photographic Expert Group), GIF (Graphic Interchange Format), or the like is used.

(G) In step S109, the identification code adding means 107 adds sequential identification codes to the small map data so that the portable device 320 displays the small maps in order along the optimum route (FIG. 4). reference).

(H) Finally, in step S110, the compressed image of the small map is transmitted from the output interface 309 to the portable device 320 by packet communication, infrared communication, cable communication, or the like. When the portable device 320 receives the image of the small map, the portable device 320 decompresses the image data and displays it on the display 321.

(Image division processing)
Various methods can be considered for the image division processing in step S107. The map division processing according to the embodiment of the present invention is based on the short side of a rectangular small map for the purpose of dividing the original map into small maps that are not interrupted between adjacent small maps along the route. This is realized by dividing a small map around a point on the route for each corresponding distance.

  Assume that the size of the display 321 of the portable device 320 in FIG. 1 is, for example, the rectangle 400 in FIG. Since the display 321 is a rectangle including a square in most portable device 320 models, the display 321 will be described as a horizontally long rectangle as an example. When displaying a small map (see FIG. 7) on which division processing has been performed, the user's route is likely to be interrupted because the current position of the user, that is, the center point 2 moves up and down parallel to the short side S of the rectangle 400. It is time to do.

  In the state where the user route is farthest, the center point 2 and the center point 2 'of the two small maps (rectangle 400 and rectangle 401) are separated by the same distance as the short side S as shown in FIG. When you are. Up to this state, the lower side of the rectangle 400 is in contact with the upper side of the rectangle 401, and the route is not interrupted between the small maps. That is, it can be said that when the distance is longer than the short side S, the user route displayed on the small map is interrupted.

  Therefore, paying attention to the length of the short side S, the user can always accurately and accurately perform the division processing from the entire map to the small map by setting so that “the moving distance of the user ≦ short side S”. Can be displayed. Hereinafter, based on this, division examples 1 to 4 will be described with reference to the drawings.

Example 1
Example 1 of the division process in step S107 will be described with reference to the flowchart of FIG. The map image before the division processing is shown in FIG. 6, where symbol A represents the start point position, E represents the end point position, and B to D represent intermediate points. FIGS. 7A to 7E are image examples of the divided small maps, and are set so that the symbols A to E are the center points, respectively.

(A) In step S200, the map image dividing unit 105 obtains the length of the short side of the display 321 included in the mobile device 320 from the map information storage unit 301, and based on this, the long division distance of the small map is increased. Set to S. For example, in FIGS. 7A to 7E, when the actual size indicated by the small map is 480 m × 320 m and the division distance S = 320 m, the size that can be displayed on the display 321 at a scale of 1/10000 is 48 mm. × 32 mm.

(B) In step S201, an image centered on the starting point position A is extracted from the map image of FIG. 6 to obtain a small map image as shown in FIG. 7A. In step S202, the distance from the previous center point (start point A) to the end point along the route is set as the remaining distance R.

(C) In step S203, it is determined whether or not the remaining distance R is equal to or less than the division distance S. If the remaining distance R is equal to or greater than the division distance S, the process proceeds to step S204. If the remaining distance R is equal to or less than the division distance S, the process proceeds to step S205.

(D) In step S204, in order to divide the intermediate point, the small map is divided around the point of the division distance S along the route from the previous center (see FIGS. 7B to 7D). Thereafter, the process returns to step S202 to determine the end of the division process again.

(E) In step S205, the end point E is divided as the center of the small map (see FIG. 7 (e)), and this division process is terminated.

  Thus, by determining the end point E in consideration of the user's moving distance ≦ the short side S, the division process from the entire map to the small map can be performed. In the above description, the display 321 is a horizontally long rectangle. However, it goes without saying that the same effect can be obtained regardless of whether it is a square or a vertically long rectangle.

(Example 2)
In the dividing process according to the first embodiment, there are cases where the end point E is included or not included in the small map divided immediately before, and thus there is a possibility that two small maps including the end point E are generated. Therefore, in the second embodiment, a division method that determines whether or not the end point is included in the previously divided small map and does not perform useless division processing will be described with reference to the flowchart of FIG.

(A) From step S300 to S303, similarly to steps S200 to S203 of FIG. 9, a division distance S setting step (S300), a start point division step (S301), and a remaining distance R determination step (S302) are performed.

(B) In step S303, it is determined whether or not the division process has ended. The remaining distance R is compared with the divided distance S or a distance S / 2 that is half of the divided distance S. If the remaining distance R is larger than the divided distance S / 2 and smaller than or equal to the divided distance S, the process proceeds to step S305. When the remaining distance R is larger than the division distance S, the process proceeds to step S304. When the remaining distance R is smaller than or equal to the division distance S / 2, it is determined that the end point is always included in the previously divided map, and the division process is terminated.

  In step S304, an intermediate point dividing process is performed as in step S204. When the dividing process is completed, the process returns to step S302 to perform the dividing process from the next center point. In step S305, as in step S205, end point division processing is performed, and this division processing ends.

  In this way, by determining whether or not the end point is included in the small map divided immediately before in the end determination step, the possibility of generating two small maps including the end point can be reduced.

(Example 3)
Next, with reference to the flowchart of FIG. 11, a division method for determining whether a small map includes the end point E based on the relationship between the user's moving distance (from the start point A to the end point E) and the division distance S will be described.

(A) First, in step S400, a distance obtained by dividing the distance along the path from the start point A to the end point E by a positive integer N so that the distance is equal to or shorter than the length of the short side of the rectangle. Is a division distance S. For example, in the case of FIG. 6, a positive integer N = 4 (B, C, D, E). When the division distance S is determined in this way, it is divided into (N + 1) small maps. As a result, the distances along the route between the centers of the adjacent small maps including the start point A and the end point E are all equal.

(B) In step S401, the starting point is divided as in step S201. In step S402, i is used as a variable for recording the number of divided small maps, and since the first small map is divided in the starting point division step of step S401, i = 1 as an initial value. Set.

(C) In step S403, since the number of small maps to be divided (= N + 1) is known, it is determined whether or not the divided small map is the Nth.

If “i” is not equal to “N”, the process proceeds to step S405. If “i” and “N” are equal, that is, if the current divided small map is the Nth, the process proceeds to step S407.

(D) In step S405, an intermediate point division step is performed in the same manner as in step S204. In step S406, the variable is incremented by 1, and the process returns to step S403. In step S407, an end point dividing step is performed as in step S205.

  Thus, the end of the division process can also be determined based on the relationship between the user's moving distance and the division distance S.

Example 4
In the fourth embodiment, the definition of the variable i in the third embodiment is improved. In the division processing according to the third embodiment, the distances along the route between the centers of the adjacent small maps including the start point A and the end point E are all equal. Therefore, the distance between the end point E and the center of the immediately preceding small map is also equal to the division distance S. That is, the end point dividing step can be replaced with the (N + 1) th intermediate point dividing step.

  Therefore, in step S403, if “i” and “N + 1” are equal in step S503, that is, if the current divided small map is (N + 1) th, the process ends, and “i” is equal to “N + 1”. If not, the same effect can be obtained by proceeding to the intermediate point dividing step (step S504).

1 is an overall configuration block diagram of a map information processing apparatus according to an embodiment of the present invention. It is a block diagram which shows CPU internal structure of a map information processing apparatus. It is a figure which shows the data structure of the image information in a map information storage part. It is a figure which shows the data structure of the file identifier in a map information storage part. It is a flowchart which shows operation | movement of a map information processing apparatus. It is a screen figure which shows an example of a map image. It is a screen figure which shows an example of a small map image. It is a figure which illustrates the structure of a screen typically. It is a flowchart which shows operation | movement of the division process of an image. It is a flowchart which shows operation | movement of the division process of an image. It is a flowchart which shows operation | movement of the division process of an image. It is a flowchart which shows operation | movement of the division process of an image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Map information processing apparatus 100 ... Display capability setting means 101 ... Start point position setting means 102 ... End point position setting means 103 ... Optimal route determination means 104 ... Map image formation means 105 ... Map image division means 106 ... Map image compression means 107 ... Identification code adding means 300 ... CPU
301 ... Map information storage unit 302 ... ROM
303 ... RAM
304 ... GPS
305 ... Sensor 306 ... Display controller 307 ... VRAM
308 ... Display 309 ... Output interface 310 ... Input interface 311 ... Internal bus 320 ... Portable device 321 ... Display

Claims (2)

In a map information processing apparatus that generates a map image showing a route from a start point to an end point, divides the map image and transmits the map image to a mobile device,
Display capability setting means for setting the display size of the display unit provided in the portable device and the type of image compression method corresponding to the data decoding method of the portable device;
A map information storage unit for storing the display size set by the display capability setting means and the type of the image compression method;
Map image forming means for forming a map image along the shortest time path from the start point to the end point;
Map image dividing means for dividing the formed map image based on the display size stored in the map information storage unit, and generating a plurality of rectangular divided maps;
A map information processing apparatus comprising: an image compression unit that compresses each of the plurality of rectangular divided maps in accordance with the type of the image compression method stored in the map information storage unit. The map image dividing means includes
Dividing the starting point as the center point of the previous rectangular division map,
The distance from the center point to the end point is the distance equal to or less than the distance corresponding to the length of one side if the short side or square of the rectangle of the previous rectangular division map is met. Set the distance along the as the remaining distance,
When the remaining distance is equal to or less than the division distance, the end point is divided as a center point of the previous rectangular division map,
When the remaining distance is larger than the division distance, a plurality of rectangular divided maps are generated by dividing a point separated from the central point along the route by the divided distance as a central point of a new rectangular divided map. The map information processing apparatus according to claim 1.

Images