JP2009043252A - Map display device and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a map display device which enables a user to obtain the positional relation of a path located between an area to be magnified and reduced and an area not to be magnified and reduced. <P>SOLUTION: In step S704, a path link angle θ with a path link P which is smaller than α and is not included in a drawing set S is selected among path links that come into contact with an end point of the path link P. The selected path links are determined with edge parts in contact with the path link P among edge parts of the selected path links as a start point, and stored in a candidate set K and the drawing set S. In step S706, a path link angle θ with the path link P which is smaller than β and is not included in the drawing set S is selected among path links in contact with the end point of the path link P. Then, the selected path links are determined with edge parts in contact with the path link P among end parts of the selected path links as a start point and stored in the candidate set K and the drawing set S. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a map display device that enlarges and displays an arbitrary range in a map.

2. Description of the Related Art Conventionally, there is known a map display device that has a screen for displaying a map and displays a part of the map in an enlarged or reduced manner according to a user's request. A map is mapped onto a curved surface having a shape corresponding to the arrangement of the enlargement / reduction portion, and a mapped image obtained thereby is projected onto a planar virtual screen to obtain a projection image. Then, by displaying the projected image on the screen, a part of the map is enlarged and reduced (Patent Document 1).
JP 2002-56400 A

  However, according to this configuration, the map displayed on the screen may be distorted. Due to this distortion, roads in a parallel positional relationship are displayed in a non-parallel positional relationship, or the angle at which the roads intersect is displayed at an angle different from the actual angle. This makes it difficult for the user to accurately grasp the actual relationship between the features.

  Further, when the difference in scale between the area to be enlarged / reduced and the area not to be enlarged / reduced increases, the distortion of the map displayed between the areas increases. This distortion makes it difficult to determine a path such as a road.

  The present invention has been made in view of these problems, and an object of the present invention is to obtain a map display device that allows a user to grasp the positional relationship between paths positioned between an area that is not enlarged or reduced and an area that is not. To do.

  The map display device according to the first invention of the present application provides a focus area for displaying the first area on the map at the first scale ratio, and a second area around the first area at the second scale ratio. A map display unit having a glue area to be displayed, and a context area for displaying a third area around the second area at a third scale ratio smaller than the first scale ratio; A map processing unit that creates a display image representing the position of the path in the glue area from the position on the map of the path that is a route that can be passed through or via a means of transportation. The display image is displayed in an area.

  The map processing unit uses first calculation means for calculating the position of the feature in the focus area from the position of the feature on the map using the first function, and a second function different from the first function. The position of the feature on the map using the second calculation means for calculating the position of the feature in the glue area from the position of the feature on the map and a third function different from the first and second functions And a third calculating means for calculating the position of the feature in the context area.

  The second scale factor may vary depending on the distance from the reference point of the focus area, and the second scale factor may be a scale factor equal to or lower than the first scale factor.

  The first function is sf · r (r ≦ rf), the second function is g (r−rf) (rf <r <rc), and the third function is g (rc−rf) + sc · ( r−rc) (r ≧ rc) is preferable. Here, the first scale ratio is sf, the second scale ratio is sc, the distance from O when the center of the focus area is O, r, and the boundary point between the focus area and the glue area to O , And the distance from the boundary point between the glue area and the context area to O is rc.

  The degree of importance may be determined for the path, and the map processing unit may create a display image representing only the position of the path for which the degree of importance equal to or greater than a predetermined value is determined.

  It is preferable that the map processing unit creates a display image representing only the position of a path connected from the focus area to the context area.

  The path includes a reference path and an extended path connected to the reference path, and the map processing unit is configured such that when the minor angle formed by the reference path and the extended path is equal to or greater than the first angle, It is preferable to create a display image representing only the position of the stretching pass. A path link closest to the concept of a road that a user generally has can be selected as a path of the road.

  The path includes a reference path, an intermediate path connected to the reference path, and an extended path connected to the intermediate path, and the minor angle formed by the reference path and the extended path is greater than or equal to the first angle. When the length of the intermediate path is equal to or shorter than the first length, the map processing unit may create a display image representing only the positions of the reference path, the extended path, and the intermediate path. A path link closest to the concept of a road that a user generally has can be selected as a path of the road.

  The path has a reference path and an extension path connected to the reference path, and there is no extension path in which the minor angle formed by the reference path and the extension path is equal to or greater than the first angle, and When the minor angle formed by the reference pass and the extension pass is smaller than the first angle and greater than or equal to the second angle smaller than the first angle, a display image representing only the positions of the reference pass and the extension pass is displayed. The map processing unit may create it. When there is no path link close to the concept of road, the second best path link can be selected as the path of road.

  The map processing unit may create a display image representing an extended path extending a certain length from a connection point between the reference path and the extended path. The user can easily grasp the state of the intersection.

  When a plurality of paths constituted by the reference path and the extension path extend from the focus area to the context area, it is preferable that the map processing unit creates a display image representing the position of the connection path connecting the paths. Users can easily grasp the connection relationship between paths.

  When the density of multiple paths displayed in the glue area is below a certain value, the map processing unit creates a display image that adds the connection path that connects multiple paths to the display image that indicates the position of multiple paths May be. It is possible to prevent a large number of paths from being displayed in the glue area, and the user can easily grasp the positional relationship of the paths.

  A first path drawn in the focus area and having a first end at the boundary between the focus area and the glue area, and a second path drawn in the context area and at the boundary between the context area and the glue area The map processing section displays the first end and the second end connected by a continuous curve so that the second path, the first path, and the second path are continuous. An image may be created. Paths can be connected smoothly.

  The curve is preferably a Bezier curve having control points at the first end and the second end. Paths can be connected smoothly.

  The curve is a Bezier curve having first, second, third, and fourth control points, the first control point is provided at the first end, and the second control point is the first path. The third control point is provided between the glue areas on the extension line of the first path extending from the first end so as to be continuous with the second path. It is preferable that the fourth control point is a Bezier curve provided at the second end portion, which is provided between the glue areas on the extension line of the second path extending from the second end portion. Paths can be connected smoothly.

  The map display server according to the second invention of the present application provides a focus area for displaying the first area on the map at the first scale ratio, and a second area around the first area at the second scale ratio. A display screen capable of displaying a glue area to be displayed and a context area for displaying a third area around the second area at a third scale ratio that is smaller than the first scale ratio. A map processing unit is provided that creates a display image representing the position of the path in the glue area from the position on the map of the path, which is a path that can be passed by humans or via a means of transportation.

  According to a third aspect of the present invention, there is provided a map display method comprising: a step of reading a position on a map of a path that is a route that a human can pass or pass through a means of transportation from the information storage unit; and a first area on the map Displaying a map in the focus area for displaying the image at the first scale ratio, and a third area around the second area at a third scale ratio that is smaller than the first scale ratio. A step of displaying a map in the context area, and a step of displaying the path using the position of the path on the map in the glue area displaying the second area around the first area at the second scale factor. It is characterized by providing.

  In addition, the path has a reference path and an extension path connected to the reference path, and the minor angle formed by the reference path and the extension path is equal to or greater than the first angle by using the positions of the reference path and the extension path. In some cases, the method may further include a step of creating a display image representing only the positions of the reference pass and the stretch pass. A path link closest to the concept of a road that a user generally has can be selected as a path of the road.

  As described above, according to the present invention, a map display device is obtained in which a user can grasp the positional relationship between paths positioned between an area that is not enlarged or reduced and an area that is not enlarged or reduced.

  Hereinafter, a first embodiment of a map display device according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram conceptually showing the map display device 110 and the database 121. The map display device 110 and the database 121 are connected by a communication line.

  The database 121 stores map information. The map information includes map image data representing a map as an image, for example, raster data, and path link data representing a path by position coordinates and size. Map image data is created for each of a plurality of scale ratios. The path is a route that can be passed by humans, such as roads, railways, bridges, and rivers, or that can be passed through transportation. The path on the map is subdivided into units called path links. When the path is a road, for example, it is subdivided into path links for each intersection. In other words, paths such as roads, rivers, and tracks are displayed on the map by using a plurality of path links.

  The path link data will be described with reference to FIG. The path link data is defined by an element definition sheet 200 created for each map scale ratio. The element definition sheet 200 includes a path link definition table 211 that defines path links, a path definition table 212 that defines paths, and a path / path link correspondence table 213 that defines correspondences between paths and path links.

  The path link definition table 211 includes the path link ID assigned to each path link, and the position coordinates, size, and shape of the end of the path link when the path link is displayed at a scale ratio corresponding to the element definition table. Is defined for each path link.

  The path definition table 212 is a table that associates a path ID, a classification code, and a path name defined for each path. The classification code is defined by being divided into a large item, a medium item, and a small item. For example, the large item indicates a type such as a road or a track, and the medium item indicates a type such as a highway or a general road. The path name defines the name of the feature to which the path corresponds.

  The path / path link correspondence table 213 is a table associating path IDs with path link path link IDs.

  The map display device 110 includes an input unit 111, a map search unit 112, a map processing unit 113, and a map display unit 114.

  The input unit 111 is an input device such as a keyboard or a pointing device, and the user inputs data to the map display device 110 using these.

  The map search unit 112 acquires map information and path link data from the database 121 according to the data input via the input unit 111 and transmits the map information and the path link data to the map processing unit 113.

  The map processing unit 113 receives the map information and the path link data from the map processing unit 113, and generates a display image to be displayed on the map display unit 114 by executing processing to be described later using these data.

  The map display unit 114 will be described with reference to FIG. The map display unit 114 includes a focus area 301 that displays a first area on the map at a first scale ratio, and a glue area that displays a second area around the first area at a second scale ratio. 302 and a context area 303 that displays a third area around the second area at a third scale ratio that is smaller than the first scale ratio, and is displayed from the map processing unit 113. The image is received, and one or both of the map and the path are displayed in each area. The glue area 302 is an area that connects between the context area 303 and the focus area 301. It can also be provided at the outer edge of the context area. The map display unit 114 can display a plurality of context areas, focus areas, and glue areas. In this case, the glue area 302 connects between the context area 303 and the focus area 301, between the two context areas 303, or between the two focus areas 301.

  Next, a process in which the map display device 110 displays a map in the context area 303 will be described.

  When a user inputs a desired area and a desired scale ratio using the input unit 111, the input unit 111 transmits data including the desired area and the desired scale ratio to the map search unit 112. The map search unit 112 that has received the data requests the database 121 for map information representing a desired area at a desired scale. The map search unit 112 reads map information related to a desired area represented by a desired scale ratio from the database 121 and transmits it to the map processing unit 113. The map processing unit 113 that has received the map information executes a context generation process, creates a display image from the map information, and transmits the display image to the map display unit 114. The context generation process is a process of generating a display image to be displayed in the context area 303 at the third scale rate. The map display unit 114 displays a map of a desired area represented by a desired scale ratio in the context area 303 (see FIG. 3). At this time, the map information is raster data representing a map.

  Next, processing for displaying a map in the focus area 301 and the glue area 302 will be described.

  When the user clicks an arbitrary point on the map displayed in the context area 303 using the input unit 111, for example, a mouse, the input unit 111 transmits the coordinates of the clicked point to the map search unit 112. The map search unit 112 that has received the coordinates acquires from the database 121 map information of a circular range centered on the coordinates of the point and having a predetermined radius. The predetermined radius is determined by the scale of the map displayed in the context area 303, the size of the context area 303, and the like. The scale rate of the acquired map information is larger than the scale rate of the map displayed in the context area 303. The map information is transmitted to the map processing unit 113 by the map search unit 112. The map processing unit 113 that has received the map information executes a focus generation process, generates a circular display image centered on the clicked point, and transmits the circular display image to the map display unit 114. The focus generation process is a process of generating a display image to be displayed in the focus area 301 using the first scale factor. The first scale factor is greater than the third scale factor. The circular display image is displayed on the map display unit 114 as the focus area 301. At this time, the map information is raster data representing a map.

  Further, the map search unit 112 acquires path data existing in a ring-shaped range around the focus area 301 and having a predetermined width from the database 121. This ring-shaped range is the glue area 302. The map search unit 112 performs glue generation processing using the acquired path data, and creates a path image to be displayed in the glue area 302. The glue generation process is a process for generating a display image to be displayed in the glue area 302 using the second scale factor. The path image is created so as to connect the path displayed in the context area 303 and the path displayed in the focus area 301. This path image is transmitted to the map display unit 114 and displayed in the glue area 302 (see FIG. 3).

  By displaying the path in the glue area 302 so as to connect the path displayed in the context area 303 and the path displayed in the focus area 301, the map displayed in the focus area 301 and the map displayed in the context area 303 The user can easily recognize the continuity.

  A plurality of focus areas 301 and glue areas 302 can also be displayed on the map display unit 114. Thereby, the user can recognize a plurality of regions that are separated on the map display unit 114 simultaneously and in detail. Also, by displaying the context area 303 and the glue area 302 between the plurality of focus areas 301, the user can intuitively grasp the relationship between the plurality of focus areas 301.

  Next, the arrangement function f (r) used for determining the scale ratio in the context generation process, the focus generation process, and the glue generation process will be described with reference to FIG. FIG. 4 shows the display image and the scale ratio converted using the arrangement function f (r).

When ra ′ = f (ra), the arrangement function f (r) corresponds to the point O in the map display unit 114 according to the distance ra from the center point O of the focus area on the map to the arbitrary point A. This is a function for calculating the distance ra ′ from the point O ′ to the point A ′ corresponding to the point A.
The r-scale function represents the slope of the placement function f (r) at a position r from the center point O, and gives a map scale s at a position r from the center point O. The r′-scale function is the slope of the arrangement function f (r) at the position of the distance r corresponding to the distance r ′, and represents the scale of the map at the position of the distance r ′ from the point O ′ on the map display unit 114. .

  The r-scale function and the r′-scale function are determined so that the scale ratio is constant in the context area and decreases monotonously when entering the glue area from the context area. Furthermore, after the monotonous decrease in the glue area, the scale factor increases as the focus area approaches a certain distance. Then, it increases monotonously until reaching the boundary between the glue area and the focus area, and the scale ratio is determined to be constant when entering the focus area. The reason for determining the scale ratio in this way will be described below.

  The scale area scale factor is larger than the context area scale factor. Therefore, the size of the focus area in the map display unit 114 is larger than the size when the map displayed in the focus area is displayed at the scale ratio of the context area. That is, the user cannot visually recognize a map located from the outer edge of the area when the map displayed in the focus area is displayed at the scale ratio of the context area to the outer edge of the focus area. In order to prevent this, the glue area displays the invisible area. Further, when the width of the glue area is not sufficiently large, the area that is not visually recognized is displayed in a compressed state in the width direction of the glue area, that is, displayed at a small scale. Therefore, the scale ratio is determined so as to monotonously decrease when entering the glue area from the context area.

  On the other hand, in the area close to the focus area in the glue area, the scale ratio monotonously increases from the glue area toward the focus area, and the scale ratios of both are determined to coincide at the boundary between the focus area and the glue area. Thereby, the features displayed in the focus area and the glue area are smoothly connected, and the user can easily recognize the map.

  The placement function f (r) is composed of child placement functions provided for each of the three types of areas, focus area, glue area, and context area. The child placement function of the glue area is g (r), the scale ratios of the focus area and the context area are sf and sc, the center of the focus area in map coordinates is O, the boundary point between the focus area and the glue area is rf, and the glue area Let rc be the boundary point of the context area. At this time, the placement function f (r) is expressed by the following equation.

  By converting the position coordinates of the path link using this arrangement function f (r), the position of the path link in the context area, the focus area, and the glue area can be calculated.

  Next, a first path determination process for determining a path to be displayed in the glue area will be described with reference to FIG. Hereinafter, a road is used as an example of a path. The first path determination process is executed by the map processing unit 113 after the map display unit 114 determines the position of the glue area.

  First, in step S501, intra-glue path link information indicating a path link having at least a part in the glue area, a path link angle θ indicating an angle formed between the path links, and main road information indicating a path link corresponding to the main road. , And information indicating the range of the focus area and the glue area is input. The main road information indicates the importance of the path and is acquired from the path definition table. The importance of a path becomes higher as it becomes a high-standard path such as a first-class river, a bullet train, and an expressway.

  Next, in step S502, the path link included in the main road information is converted into a DL and stored in the drawing set S. The process of determining the start and end parts of the path link is called DL conversion. The drawing set S is a set of path links displayed in the glue area.

  In the next step S503, the path link spanning the focus area and the glue area is DL-converted with the end located in the focus area as the start and the end located in the glue area as the end, and the drawing set S and candidate set Store in K. The candidate set K is a set of path links that are displayed in the glue area and for which it is not determined whether a path link connected to the end of the candidate set K is displayed in the glue area.

  In step S504, a road classification process described later is executed. In the road classification process, a path link having a path relationship with the path link stored in the candidate set K is searched from the intra-glue path link information and added to the drawing set S. This is a process of updating the adjacent set R with the set, and is executed in the map processing unit 113. The road classification processing includes a drawing set S, a candidate set K, an adjacent set R, intra-glue path link information indicating a path link having at least a part in the glue area, and a path link angle θ indicating an angle formed between the path links. , And information indicating the range of the focus area and the glue area is passed. The road classification process updates the drawing set S, candidate set K, and adjacent set R, and returns them to the first path determination process. The adjacent set R is a set of path links that have end portions in contact with the end portions of the path links belonging to the drawing set S and are not stored in the drawing set S. That is, a path link that has an end portion that is in contact with an end portion of the path link stored in the drawing set S and has no path relationship with the path link stored in the drawing set S is stored in the adjacent set R.

  In step S505, the glue area is divided into small areas. The areas of the divided small regions are substantially equal.

  Then, a small area loop is executed for each small area from step S506 to step S516.

In step S507, the ratio r of the road area occupying the small area is calculated by the following mathematical formula.
r = (total area of roads existing in the small area and belonging to the drawing set S) / (area of the small area)

  In step S508, it is determined whether the ratio r is smaller than the threshold value γ. The threshold value γ is a numerical value designated by the user and is the maximum value of the ratio of the road area to the small area. When the ratio r is greater than or equal to the threshold γ, the process proceeds to step S516, and a small area loop is executed for the next small area. When the ratio r is smaller than the threshold value γ, the process proceeds to step S509.

  In step S509, the connection path link connected to the end portion of the path link string formed by connecting a plurality of path links is determined. Among the connection path links, a connection path link having an end portion in a small area and not belonging to the drawing set S is selected.

  In step S510, it is determined whether a path link has been selected. If no path link is selected, the process proceeds to step S511. If a path link is selected, the process proceeds to step S513.

  In step S511, a path link whose end is in the small area and belongs to the adjacent set R is selected. By executing step S511 when not selected in step S509, it is possible to preferentially select a path link connected to the end of the path link string.

  In step S512, it is determined whether a path link has been selected. If no path link is selected, the process proceeds to step S516, and a small area loop is executed for the next small area. If a path link is selected, the process proceeds to step S513.

  In step S513, only one path link L having the smallest angle υ formed by the straight line extending from the center of gravity B of the focus area to the start end F of the path link L and the path link L is selected from the path links selected in step S509. (See FIG. 6). The selected path link is defined as a path link P. By selecting a path link L having the smallest angle υ, a path link that tends to extend in the context area direction can be selected. For this reason, as the path link is converted to DL, the path link tends to extend from the focus area to the context area.

  In step S514, the candidate set K is created using the path link P as an element, the path link P is added to the drawing set S, and the path link P is deleted from the adjacent set R.

  In step S515, a road classification process described later is executed. A drawing set S, a candidate set K, an adjacent set R, path link information in a small area indicating a path link having at least a part in the small area, a path link angle θ indicating an angle formed between the path links, a focus area, and Information indicating the range of the glue area is passed to the path classification process. The road classification process updates the drawing set S, candidate set K, and adjacent set R, and returns them to the first path determination process. A path link that has an end portion that is in contact with an end portion of the path link stored in the drawing set S and is not related to the path link stored in the drawing set S is stored in the adjacent set R.

  After the road classification process is executed in step S515, the process returns to step S507. And the process from step S507 to S515 is repeated until the ratio r of the road area which occupies for a small area becomes more than threshold value (gamma). Thus, the path links in the small area are stored in the drawing set S until the road area ratio r in the small area is equal to or greater than the threshold γ. By drawing the path links belonging to the drawing set S on the map display unit 114 as described above, the ratio r of the road area occupying the small area becomes equal to or greater than the threshold value γ.

  If there is no path link to be displayed in the small area before the ratio r of the road area occupying the small area becomes equal to or greater than the threshold value γ, the process is executed for the next small area.

  Then, after repeating the small area loop for all the small areas, the drawing set S is output in step S517, and the first path determination process is completed.

  Thereby, all the paths existing in the glue area are not displayed, and the density of the displayed paths can be appropriately maintained according to the user's request (see FIG. 7).

  Next, the road classification process will be described with reference to FIGS.

  First, in step S701, the drawing set S, the candidate set K, the adjacent set R, the intra-glue path link information indicating a path link having at least a part in the glue area, the path link angle θ indicating the angle formed between the path links, Information indicating the range of the focus area and the glue area is received.

  In the next step S702, one path link is selected from the candidate set K. The selected path link is defined as a path link P, and the following processing from steps S703 to S708 is executed for the path link P.

  In step S703, it is determined whether the end of the path link P is outside the glue area. In the following steps, among the path links connected to the end of this path link P, the one that becomes a path for the path link P is selected. If the end of the path link P is outside the glue area, there is no need to display the path link connected to the end of the path link P. Therefore, the process proceeds to step S708, and the path link P is deleted from the candidate set K. If the end of the path link P is within the glue area, the process proceeds to step S704.

  In step S704, a path link having a path link angle θ with the path link P smaller than α and not included in the drawing set S is selected from the path links in contact with the end of the path link P. Then, with the end portion of the selected path link contacting the path link P as the start end, the selected path link is converted into a DL and stored in the candidate set K and the drawing set S. That is, the path link angle θ with the path link P that is smaller than α is selected from a plurality of path links that are in contact with the end of the path link P (see FIG. 9). Thereby, a path link close to the concept of a road that a user generally has can be selected as a path of the road.

  Next, in step S705, it is determined whether or not one or more path links have been selected in the process of step S704. If it is selected, the process proceeds to step S707 without executing the next step S706. If not selected, the next step S706 is executed.

  In step S706, a path link having a path link angle θ with the path link P smaller than β and not included in the drawing set S is selected from the path links in contact with the end of the path link P. Then, with the end portion of the selected path link contacting the path link P as the start end, the selected path link is converted into a DL and stored in the candidate set K and the drawing set S. That is, the path link angle θ with the path link P that is smaller than β is selected from a plurality of path links in contact with the end of the path link P (see FIG. 9). Thereby, when there is no path link close to the concept of the road, the second best path link can be selected as the path of the road.

  In step S707, a path link that is not stored in the candidate set K and the drawing set S is selected from the path links in contact with the end of the path link P. Then, the selected path link is converted into a DL and stored in the adjacent set R, starting from the edge of the selected path link that is in contact with the path link P. That is, the path link angle θ with the path link P that is equal to or larger than β is selected from a plurality of path links in contact with the end of the path link P (see FIG. 9). As described above, the adjacent set R is used in the first path determination process.

  In addition, when the path link converted into DL has already been stored in the adjacent set R, the path link newly converted into DL is not stored. A path having a loop structure is prevented from being overlapped and stored in the adjacent set R.

  In step S708, the path link P is deleted from the candidate set K. Then, in step S709, it is determined whether the candidate set K is empty. If the candidate set K is not empty, the process proceeds to step S702, and the processes from step S702 to S708 are repeated until the candidate set K becomes empty. If the candidate set K is empty, the process proceeds to step S710.

  In step S710, the drawing set S, the adjacent set R, and the candidate set K are returned to the first path determination process, and the road classification process ends.

  As a result, a path that becomes a road can be obtained, and a path that does not become a road can also be obtained.

  According to this embodiment, not only main paths but also small paths can be displayed. In addition, the path link can be extended from the focus area to the context area. Furthermore, the user can appropriately recognize the path by appropriately maintaining the density of the path displayed in the glue area.

  A second embodiment according to the present invention will be described with reference to FIGS. The description of the same configuration as that of the first embodiment is omitted.

  The configuration of the map display device 110 is the same as that of the first embodiment. The map display device 110 according to the present embodiment performs a process of drawing a path link as long as the path link that contacts the end of the path link exists in the glue area. That is, the path link is not interrupted in the glue area. This process is executed by the second drawing path determination process.

  A second drawing path determination process for determining a path to be displayed in the glue area will be described with reference to FIG. Hereinafter, a road is used as an example of a path. The second path determination process is executed by the map processing unit 113 after the map display unit 114 determines the position of the glue area.

  First, in step S1001, intra-glue path link information indicating a path link having at least a part in the glue area, path link angle θ indicating an angle formed between the path links, and main road information indicating a path link corresponding to the main road. , And information indicating the range of the focus area and the glue area is input. The main road information is acquired from the path definition table.

  Next, in step S1002, the path links included in the main road information that are in contact with each other are converted into DLs, and new path links are created. The created path link is stored in the drawing set S.

  In the next step S1003, the path link spanning the focus area and the glue area is DL-converted with the end located in the focus area as the start and the end located in the glue area as the end, and the drawing set S and candidate set Store in K.

  In step S1004, the road classification process described above is executed. In the road classification process, the drawing set S, candidate set K, and adjacent set R are updated and returned to the second path determination process.

  In step S1005, among the path links included in the drawing set S, those that are in contact with each other are converted into a DL and a new path link is created. All the path links that contact each other's ends are converted to DL, and new path links are created until there are no path links that contact each other's ends. The created path link is stored in the drawing set S.

  In step S1006, after the candidate set K is emptied, all the path links included in the drawing set S are copied to the candidate set K.

  In steps S1007 to S1011, the processing from steps S1008 to S1010 is executed for all path links belonging to the candidate set K. This series of processing is executed to search for a path link having an end portion that is not connected in the glue area. For example, a road that has a dead end in the glue area corresponds to this.

  In step S1007, one path link is selected from the candidate set K and is designated as a path link P.

  In step S1008, it is determined whether the end of the path link P is within the glue area.

  If the end of the path link P is in the glue area, it is determined that there is no path link in contact with the end of the path link P, and the process advances to step S1009 to store the path link P in the interruption set K ′. If the end of the path link P is not within the glue area, it is considered that the path link P is connected from the focus area to the context area, and thus the process proceeds to step S1010.

  In step S1010, the path link P is deleted from the candidate set K, and in subsequent step S1011, it is determined whether or not the candidate set K is empty. If the candidate set K is not empty, the process returns to step S1007, and steps S1008 to S1010 are executed for other path links belonging to the candidate set K. If the candidate set K is empty, the process proceeds to step S1012.

  In step S1012, it is determined whether or not the interruption set K ′ is empty. If the suspended set K ′ is not empty, the process proceeds to step S1013. If the suspended set K ′ is empty, it is considered that there is no path that is interrupted, that is, a dead end in the glue area, so the process proceeds to step S1022, and the updated drawing set S, adjacent set R, and A candidate set K is output.

  In the processing from step S1013 to S1018, a search is made as to whether there is a path link connected to the end of the interrupted set K ', and if it exists, DL processing is performed. In step S1013, one path link is selected from the suspended set K 'to be a path link P.

  In step S1014, a path link having an end adjacent to the end of the path link P is selected from the adjacent set R. The adjacent set R is a set of path links that have end portions in contact with the end portions of the path links belonging to the drawing set S and do not belong to the drawing set S.

  In step S1015, it is determined whether or not selection was possible in step S1014. If it can be selected, the process proceeds to step S1016. If it cannot be selected, the process proceeds to step S1017 without executing step S1016.

  In step S1016, only one path link having the smallest angle υ formed by the straight line extending from the center of gravity B of the focus area to the start end of the path link and the path link is selected from the path links selected in step S509 (see FIG. 6). ). The selected path link is defined as a path link P ′. Then, the path link P ′ is stored in the drawing set S and the candidate set K. By selecting a path link P ′ having the smallest angle υ, a path link that tends to extend in the context area direction can be selected. For this reason, as the path link is converted to DL, the path link tends to extend from the focus area to the context area.

  In step S1017, the path link P is deleted from the interruption set K ′. Then, in step S1018, it is determined whether or not the interruption set K ′ is empty. If the interrupt set K ′ is not empty, the process proceeds to step S1013, and the processes from step S1013 to S1017 are repeated until the interrupt set K ′ becomes empty. If the suspended set K ′ is empty, the process proceeds to step S1019.

  In step S1019, it is determined whether the candidate set K is empty. If the candidate set K is empty, it means that there is no path link extending from the path link P, so the process proceeds to step S1021 and ends. If the candidate set K is not empty, it means that there is a path link extending from the path link P. Therefore, a road classification process is executed in step S1020.

  By executing the road classification process in step S1020, the path link closest to the concept of the road that the user generally has among the path links extending from the path link P can be selected as the road path. When step S1020 ends, the process returns to step S1005.

  When the processes from step S1005 to S1012 are executed again and the interrupted set K ′ becomes empty, the drawing set S, the adjacent set R, and the candidate set K updated in step S1022 are output. Thereby, the path links connected to the ends of the path link P can be accumulated in the drawing set S and the candidate set K.

  Then, the map processing unit 113 draws the path link stored in the drawing set S in the glue area.

  By repeatedly executing the processing in step S1005 and subsequent steps, path links existing in the glue area can be connected according to the presence of an actual path (see FIG. 11).

  A third embodiment according to the present invention will be described with reference to FIGS. The description of the same configuration as in the first and second embodiments is omitted.

  The configuration of the map display device 110 is the same as that of the first embodiment. The map display device 110 according to the present embodiment performs a process of drawing only one path link that contacts the end of the path link existing in the glue area. That is, the state where the path link branches is drawn. This process is executed by the third drawing path determination process.

  A third drawing path determination process for determining a path to be displayed in the glue area will be described with reference to FIG. Hereinafter, a road is used as an example of a path. The third path determination process is executed by the map processing unit 113 after the position of the glue area is determined in the map display unit 114.

  Since the processing from step S1201 to step S1217 and the processing of step S1222 are the same as the processing from step S1001 to step S1017 and the processing of step S1022 in the second path determination processing, description thereof will be omitted.

  In step S1218, it is determined whether or not the interruption set K ′ is empty. If the interrupt set K ′ is not empty, the process proceeds to step S1213, and the processes from step S1213 to S1217 are repeated until the interrupt set K ′ becomes empty. If the suspended set K ′ is empty, the process proceeds to step S1219.

  Thereafter, the process ends in step S1219. Thereby, path links extending from the end of the path link P can be accumulated in the drawing set S and the candidate set K.

  Then, the map processing unit 113 draws the path link stored in the drawing set S in the glue area. Since the process of step S1020 in the second path determination process, that is, the road classification process is not repeated, only one path link that contacts the end of the path link existing in the glue area is drawn (see FIG. 13).

  According to the present embodiment, it is possible to display the state where the path link branches in the glue area.

  In step S1216, all the path links selected in step S1214 may be stored in the drawing set S and candidate set K without selecting the path link having the smallest angle υ. Thereby, all the path links can be drawn.

  A fourth embodiment according to the present invention will be described with reference to FIGS. The description of the same configuration as that of the first embodiment is omitted.

  The configuration of the map display device 110 is the same as that of the first embodiment. The map display apparatus 110 according to the present embodiment performs a process of drawing path links that connect path links existing in the glue area to each other. This process is executed by a fourth drawing path determination process.

  A fourth drawing path determination process for determining a path to be displayed in the glue area will be described with reference to FIG. Hereinafter, a road is used as an example of a path. The fourth path determination process is executed by the map processing unit 113 after the position of the glue area is determined in the map display unit 114.

  Since the processing from step S1401 to step S1406 is the same as the processing from step S1001 to step S1006 in the second path determination processing, description thereof will be omitted.

  In steps S1407 to S1411, the processes from steps S1408 to S1410 are executed for all path links belonging to the candidate set K. This series of processing is executed to search for a path link having an end portion that is not connected in the glue area. For example, a road that has a dead end in the glue area corresponds to this.

  In step S1407, one path link is selected from the candidate set K and is designated as a path link P.

  In step S1408, it is determined whether a path link belonging to the drawing set S other than the path link P and the path link P intersect.

If the path link P does not intersect with any other path link, the process advances to step S1409 to store the path link P in the interruption set K ′. As a result, path links P that do not intersect with other path links are collected in the interruption set K ′. Then, the process proceeds to step S1410.
If the path link P intersects with another path link, there is no need to draw path links that connect the path links to each other, and thus the process proceeds to step S1410, and the path link P is deleted from the candidate set K.

  In step S1411, it is determined whether the candidate set K is empty. If the candidate set K is not empty, the process returns to step S1407, and steps S1408 to S1410 are executed for other path links belonging to the candidate set K. If the candidate set K is empty, the process proceeds to step S1412.

  In the processing from step S1412 to S1416, a search is made for a path link that connects an intermediate point of the path link belonging to the interrupted set K ′ and another path link, and the found path link is stored in the drawing set S. . An intermediate point of the path link is called an intermediate node, and indicates a connection point between the path link and the path link connected by DL.

  In step S1412, one path link is selected from the suspended set K 'to be a path link P.

  In step S1413, E is the end of the path link belonging to the drawing set S that is closest to the end of the path link P.

  In step S1414, a path link constituting a route from the intermediate node C to the terminal E is searched using a known route search method, for example, Dijkstra method, with the starting point being the intermediate node C and the destination being the terminal E. Then, the obtained path link is stored in the drawing set S.

  In step S1415, the path link P is deleted from the interruption set K ′. Then, in step S1416, it is determined whether or not the interruption set K ′ is empty. If the interrupt set K ′ is not empty, the process returns to step S1412 and repeats the processes from steps S1412 to S1415 until the interrupt set K ′ becomes empty. If the suspended set K ′ is empty, it is considered that all the path links P intersect with other path links, so the process proceeds to step S1417, and the updated drawing set S, adjacent set R, and candidate set K are stored. Output. As a result, the path links connecting the path links existing in the glue area can be accumulated in the drawing set S.

  Then, the map processing unit 113 draws the path link stored in the drawing set S in the glue area.

  Thereby, the path link which connects the path links which exist in a glue area mutually can be displayed on the map display part 114 (refer FIG. 15).

  According to the present embodiment, it is possible to display the path link connecting the path links in the glue area.

  A fifth embodiment according to the present invention will be described with reference to FIGS. The description of the same configuration as that of the first embodiment is omitted.

  The configuration of the map display device 110 is the same as that of the first embodiment. The map display device 110 according to the present embodiment smoothly displays a path on the boundary between the focus area and the glue area and on the boundary between the context area and the glue area. For this purpose, the processing performed by the map processing unit 113 is referred to as path smoothing processing. Hereinafter, an embodiment will be described in which a path smoothing process is used to connect a path endpoint p1 on the boundary between the focus area and the glue area and a path endpoint p4 on the boundary between the context area and the glue area.

  FIG. 17 shows a path displayed on the map display unit 114 without executing the path smoothing process. Since the scale of the map changes on the boundary between the focus area and the glue area and on the boundary between the context area and the glue area, the path changes acutely. In order to correct this acute change, a path smoothing process is executed.

  The tangent line of the path l1 displayed in the focus area at the end point p1 is m1, and the tangent line of the path l2 displayed in the context area at the end point p4 is m2. The first control point p2 is placed on the tangent line m1 and at a substantially middle point of the glue area. The second control point p3 is placed on the tangent line m2 and at a substantially middle point of the glue area. Then, a Bezier curve connecting the end points p1 and p4 is drawn with the first and second control points p2 and p3 as control points.

  FIG. 18 shows a path displayed on the map display unit 114 after the path smoothing process is executed. A path is drawn according to a Bezier curve from the boundary between the focus area and the glue area to the boundary between the context area and the glue area. Therefore, the path displayed in the glue area is displayed smoothly.

  According to the present embodiment, path distortion caused by a change in the scale ratio is reduced.

  Note that the first and second control points p2 and p3 do not have to be approximately the middle point of the glue area, and may be any position where the user feels that the path is displayed smoothly.

  A map display system according to the sixth embodiment will be described with reference to FIG. The description of the same configuration as that of the first embodiment is omitted.

  The map display system includes a map display server 1910 and a client 1930n. The map display server 1910 includes a database 1921 which is an information storage unit, a map search unit 1912, a map processing unit 1913, and a server control unit 1914. The client 1930n includes a client control unit 1932n, an input unit 1933n, and a map display unit 1931n. The map display server 1910 and the client 1930n are connected by a network.

  The input unit 1933n is an input device such as a keyboard or a pointing device, and the user inputs data to the client 1930n using these. The client control unit 1932n transmits the input data to the map display server 1910.

  The server control unit 1914 receives input data from the client 1930n and transmits it to the map search unit 1912. The map search unit 1912 acquires map information and path link data from the database 1921 according to the received input data, and transmits it to the map processing unit 1913.

  The map processing unit 1913 receives the map information and the path link data from the map search unit 1912 and executes the above-described processing using these data, thereby generating a display image to be displayed on the map display unit 1931n. Then, the server control unit 1914 transmits the display image to the client 1930n.

  The map display unit 1931n has a focus area for displaying the first area on the map at the first scale ratio, and a glue area for displaying the second area around the first area at the second scale ratio. And a context area for displaying a third area around the second area at a third scale ratio that is smaller than the first scale ratio, and receiving a display image from the map display server 1910 Then, one or both of the map and the path are displayed in each area.

  Next, processing in which the client 1930n displays a map in the context area using the map display system will be described.

  When the user inputs a desired area and a desired scale ratio using the input unit 1933n, the client control unit 1932n transmits data including the desired area and the desired scale ratio to the map display server 1910 via the network. To do. The map display server 1910 that has received the data transmits the data to the map search unit 1912 via the server control unit 1914. The map search unit 1912 requests the database 1921 for map information representing a desired area at a desired scale ratio. The map search unit 1912 reads map information related to a desired area represented by a desired scale ratio from the database 1921 and transmits it to the map processing unit 1913. Upon receiving the map information, the map processing unit 1913 executes a context generation process and creates a display image from the map information. The server control unit 1914 transmits the display image to the client 1930n via the network. The client 1930n that has received the data transmits the data to the map display unit 1931n via the client control unit 1932n. The map display unit 1931n displays a map of a desired area represented by a desired scale ratio in the context area (see FIG. 3).

  Next, processing for displaying a map in the focus area and the glue area will be described.

  When the user clicks an arbitrary point on the map displayed in the context area using the input unit 1933n, for example, with a mouse, the client control unit 1932n sends the coordinates of the clicked point to the map display server 1910 via the network. Send. The map display server 1910 that has received the data transmits the data to the map search unit 1912 via the server control unit 1914. The map search unit 1912 that has received the coordinates obtains from the database 1921 map information of a circular range centered on the coordinates of the point and having a predetermined radius. The predetermined radius is determined by the scale ratio of the map displayed in the context area, the size of the context area, and the like. The scale rate of the acquired map information is larger than the scale rate of the map displayed in the context area. The map information is transmitted to the map processing unit 1913 by the map search unit 1912. Upon receiving the map information, the map processing unit 1913 executes a focus generation process and generates a circular display image centered on the clicked point. The server control unit 1914 transmits the display image to the client 1930n via the network. The client 1930n that has received the display image transmits the display image to the map display unit 1931n via the client control unit 1932n. The map display unit 1931n displays the display image in the focus area (see FIG. 3).

  Further, the map search unit 1912 acquires path data existing in a ring-shaped range around the focus area and having a predetermined width from the database 1921. This ring-shaped range is a glue area. Then, the map search unit 1912 performs glue generation processing using the acquired path data, and creates a path image to be displayed in the glue area. The path image is created so as to connect the path displayed in the context area and the path displayed in the focus area. This path image is transmitted by the server control unit 1914 to the client 1930n via the network. The client 1930n that has received the path image transmits the path image to the map display unit 1931n via the client control unit 1932n. The map display unit 1931n displays the path image in the glue area (see FIG. 3).

  According to this embodiment, a user can refer to a map via a network.

  Note that the number of clients 1930n is not limited to three.

  In the road classification process, it may be determined whether or not the road is in accordance with the length of the path link. In order to determine this, the following processing is performed between steps S703 and S704. This will be described with reference to FIG. First, when there is one path link that contacts the end of the path link P, the path link is DL-stored in the candidate set K and the drawing set S with the connection point with the path link P as the start end. Then, the process proceeds to step S708. When there is not one path link that contacts the end of the path link P, the path link Q that has a length l that is equal to or smaller than a predetermined value and is not included in the drawing set S among the path links that contact the end of the path link P. Select. Next, a path link that has an angle θ with the path link P that is equal to or smaller than a predetermined value and that is not included in the drawing set S is selected from the path links that contact the end of the path link Q. Then, the selected path link and path link Q are converted to DL and stored in the candidate set K and the drawing set S. Then, the process from step S704 is executed with the selected path link as the path link P. That is, among the path links connected to the path link P, the path link Q having a short length is determined as a road. When there are a plurality of such path links Q, these processes are performed for all the path links. Thereby, a path link close to the concept of a road that a user generally has can be selected as a path of the road.

  Alternatively, only the path links with high importance may be stored in the drawing set S without executing the road classification process, and only those path links may be displayed in the glue area 2102 (see FIG. 21). A path link with high importance connects a path existing in the focus area and a path existing in the context area. Thereby, the user can easily recognize a road with high importance.

  The main road information may not be retrieved from the path definition table but may be specified by the user.

It is the block diagram which showed the outline of the map display apparatus by 1st Embodiment. It is a figure which shows the data structure of path link data. It is a figure which shows the focus area, glue area, and context area which were displayed on the map display part. It is the graph which showed the relationship between a placement function and a scale ratio. It is a flowchart which shows a 1st path | pass determination process. It is a flowchart which shows angle υ. It is a figure which shows typically the path link drawn in a glue area. It is a flowchart which shows a road classification process. 4 is a diagram showing a path link connected to the end of a path link P. FIG. It is a flowchart which shows a 2nd path | pass determination process. It is a figure which shows typically the path link drawn by the glue area using the 2nd path determination processing. It is a flowchart which shows a 3rd path | pass determination process. It is a figure which shows typically the path link drawn in a glue area using a 3rd path | pass determination process. It is a flowchart which shows a 4th path | pass determination process. It is a figure which shows typically the path link drawn by the glue area using a 4th path | pass determination process. It is a figure which shows typically the path link connected by a Bezier curve. It is a figure which shows the path link connected without using a Bezier curve. It is a figure which shows the path link connected by a Bezier curve. It is a figure showing a map display system roughly. It is a figure which shows typically the path link P to which the path link below a predetermined value is connected. It is a figure which shows the map display part which displayed only the main path | pass in the glue area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Map display apparatus 111 Input part 112 Map search part 113 Map processing part 114 Map display part 121 Database 1910 Map display server 1911 Input part 1912 Map search part 1913 Map processing part 1914 Server control part 1921 Database 1930n Client 1931n Map display part 1932n Client Control unit 1933n Input unit

Claims (21)

A focus area that displays a first area on the map at a first scale, a glue area that displays a second area around the first area at a second scale, and the second area A map display unit having a context area for displaying a third area around the area at a third scale ratio smaller than the first scale ratio;
A map processing unit that creates a display image representing the position of the path in the glue area from the position on the map of the path that is a route that can be passed by humans or through a means of transportation;
The map display unit displays the display image in the glue area.   The map processing unit uses a first function to calculate a position of the feature in the focus area from a position of the feature on the map, and a second different from the first function. A second calculation means for calculating the position of the feature in the glue area from the position of the feature on the map using a function, and a third function different from the first and second functions on the map The map display device according to claim 1, further comprising: a third calculation unit that calculates the position of the feature in the context area from the position of the feature in   The map display device according to claim 2, wherein the second scale ratio changes according to a distance from a reference point of the focus area.   The map display device according to claim 2, wherein the second scale factor is a scale factor equal to or lower than the first scale factor. The first function is sf · r (r ≦ rf),
The second function is g (r−rf) (rf <r <rc),
The third function is g (rc−rf) + sc · (r−rc) (r ≧ rc)
The map display device according to claim 1, defined by:
Here, the first scale ratio is sf, the second scale ratio is sc, the distance from O when the center of the focus area is O, r, and the boundary point between the focus area and the glue area to O , And the distance from the boundary point between the glue area and the context area to O is rc. Importance is defined for the path,
The map display device according to claim 1, wherein the map processing unit creates a display image that represents only a position of a path having a degree of importance equal to or greater than a predetermined value.   The map display device according to claim 1, wherein the map processing unit creates a display image representing only a position of a path connected from the focus area to the context area. The path has a reference path and an extension path connected to the reference path,
The map processing unit creates a display image representing only the positions of the reference path and the extended path when the angle of the minor angle formed by the reference path and the extended path is equal to or greater than a first angle. The map display device described in 1. The path includes a reference path, an intermediate path connected to the reference path, and an extended path connected to the intermediate path.
When the angle of the minor angle formed by the reference pass and the extension pass is not less than the first angle and the length of the intermediate pass is not more than the first length, the reference pass, the extension pass, and The map display device according to claim 1, wherein the map processing unit creates a display image representing only the position of the intermediate path. The path has a reference path and an extension path connected to the reference path,
There is no stretching pass such that the angle of the minor angle formed by the reference pass and the stretching pass is equal to or greater than the first angle, and the angle of the minor angle formed by the reference pass and the stretching pass is The map processing unit creates a display image representing only the positions of the reference path and the extended path when the angle is smaller than the first angle and equal to or larger than the second angle smaller than the first angle. The map display device described in 1.   The map display device according to claim 8, wherein the map processing unit creates a display image representing the extended path extending a certain length from a connection point between the reference path and the extended path.   The map processing unit creates a display image indicating a position of a connection path connecting the paths when a plurality of paths configured by the reference path and the extended path extend from the focus area to the context area. 9. The map display device according to 8.   When the density of a plurality of paths displayed in the glue area is a predetermined value or less, a display image obtained by adding a connection path connecting the plurality of paths to a display image indicating the positions of the plurality of paths is displayed on the map. The map display device according to claim 8, which is created by the processing unit. A first path drawn in the focus area and having a first end at a boundary between the focus area and the glue area;
A second path drawn in the context area and having a second end at the boundary between the context area and the glue area;
The map processing unit displays the display image by connecting the first end and the second end with a continuous curve so that the first path and the second path are continuous. The map display device according to claim 1 which creates   The map display device according to claim 14, wherein the curve is a Bezier curve having control points at the first end and the second end. The curve is a Bezier curve having first, second, third and fourth control points;
The first control point is provided at the first end;
The second control point is an extension of the first path extending from the first end so as to be continuous with the first path, and is provided between the glue areas,
The third control point is an extension of the second path extending from the second end so as to be continuous with the second path, and is provided between the glue areas,
The map display device according to claim 15, wherein the fourth control point is a Bezier curve provided at the second end.   A focus area that displays a first area on the map at a first scale, a glue area that displays a second area around the first area at a second scale, and the second area A human can pass through a display screen that can display a context area that displays a third area around the area at a third scale ratio that is smaller than the first scale ratio, or traffic A map display server comprising a map processing unit that creates a display image representing a position of a path in the glue area from a position on a map of a path that is a path that can be passed through the means. A step of reading from the information storage unit the position on the map of a path that is a path that a human can pass or is able to pass through means of transportation;
Displaying a map in a focus area displaying a first area on the map at a first scale factor;
Displaying a map in a context area at a third scale ratio that is smaller than the first scale ratio of a third area around the second area;
A map display method comprising: displaying the path using a position on the map of the path in a glue area that displays a second area around the first area at a second scale factor. The path has a reference path and an extension path connected to the reference path;
Display indicating only the positions of the reference path and the extension path when the angle of the minor angle formed by the reference path and the extension path is equal to or larger than the first angle by using the positions of the reference path and the extension path. The map display method according to claim 18, further comprising a step of creating an image.   A program for causing a map display device to execute the map display method according to claim 19.   A program according to a fourth invention of the present application causes a map display device to execute the map display method.