JP4836289B2 - Compression device, route search device, navigation system, operation method of compression device, operation method of route search device, and operation method of navigation device - Google Patents

Description

  The present invention relates to a technique for compressing a data amount of coordinate information on a map such as latitude and longitude.

  Currently, map data that can be browsed on a user terminal is provided in various forms such as use of ASP via the Internet or installation on a stand-alone user terminal. In such map data, coordinate points on the map can be specified based on latitude and longitude information, and the positions and routes of landmarks can be displayed.

  By the way, if the data indicating these coordinates is latitude / longitude information, for example, “35.658625, 139.745415”, there is a difference depending on the position resolution, but in order to provide a service of a predetermined level or higher. It must be represented by a numeric data string with a large number of digits. For this reason, in the case of a route search service via the Internet, if data indicating these coordinates is transmitted to the user terminal as it is, there will be a problem that it takes time for communication and display of map information is slow. Therefore, various compression methods for reducing the amount of data indicating coordinates such as latitude and longitude information are provided.

  For example, in Patent Document 1, position information of a predetermined node on a map is converted into data having a numerical deviation by representing the deviation information from the immediately preceding node (the numerical range is between −180 and 180). In addition, since the declination is deviated to 0 degrees if it is a straight line), a technique for reducing the amount of data by variable length coding is disclosed.

  In general, as a method for compressing the data size of a numerical data group, a method using the difference is also used. In this method, a difference value from the previous numerical value is calculated for the data group, and the data group is expressed by the difference value, for example, the data group “10000, 10010, 10020” is changed to “10000, +10, The amount of information (number of bits) can be made small, such as “+10”.

JP 2003-23357 A

  However, the conventional compression technique has the following problems. That is, in the technique of Patent Document 1, since the load of conversion processing when expressing a node with a declination is high, a high arithmetic processing capability is required on the device side, or the processing takes time and the user is kept waiting. There is a problem such as.

  For data compression using the above difference, for example, if the values of numerical data are approximated as in the above example, the compression efficiency can be maintained high. However, in the case of data having greatly different values, for example, “30000” If the data group is “10”, there is a problem that the data amount may increase, for example, the difference becomes “30000, −29990”. In addition, if it is determined whether or not the amount of data can be reduced in order to avoid this, it will take a long processing time.

  In order to solve the above-described problems, the present invention accepts a coordinate set on a map that is mainly composed of adjacent points and approximates a high-order digit, calculates a difference with respect to the coordinate set, and performs data processing. A coordinate compression apparatus having a function of compressing a quantity is provided.

  Specifically, a coordinate set receiving unit that receives a set of coordinates representing a position on the map as a set, and a reference coordinate selection unit that selects a reference coordinate from a plurality of coordinates included in the acquired coordinate set A difference coordinate acquisition unit that performs a difference calculation between a reference coordinate included in the coordinate set and another coordinate and acquires the other coordinate as a difference coordinate, and a set of a reference coordinate and a difference coordinate not represented as the difference coordinate And a compressed coordinate set output unit that outputs a compressed coordinate set corresponding to the coordinate set that has received the coordinate set.

  In addition, on the basis of the above configuration, a coordinate compression device is also provided in which the reference coordinate selection unit includes a relative selection unit that also selects a coordinate to be expressed as a difference coordinate as the reference coordinate.

  In addition, for example, the route searched by the route search is composed of coordinate sets indicated by latitude and longitude that are extremely close in value and continuously change, so that the compression efficiency can be further improved. Therefore, based on one of the above configurations, the coordinate set receiving unit receives a plurality of coordinates as a route set in order to represent the route on the map as a line in which a plurality of coordinates are adjacent to each other. Adjacent coordinate selection means that has a set reception means, and the reference coordinate selection unit always selects, as the reference coordinates, coordinates adjacent to the coordinates to be calculated in the difference coordinate acquisition unit from among a plurality of coordinates included in the route set A coordinate compression apparatus having

  In addition, a route search device including the coordinate compression device configured as described above, and a navigation system including the route search device and a terminal device are also provided. In addition, an operation method of the coordinate compression device, route search device, and navigation system is also provided.

  According to the present invention having the above-described configuration, the data amount of the coordinate group can be efficiently compressed without applying a processing load. Accordingly, even in a communication-type navigation system via a relatively low-speed network such as a mobile phone network, the coordinate set can be transmitted to the client terminal at a speed that does not feel stress.

FIG. 3 is a conceptual diagram for explaining an example of a coordinate group compression process in the coordinate compression apparatus according to the first embodiment. The figure showing an example of the functional block in the coordinate compression apparatus of Example 1. The conceptual diagram showing an example of the difference coordinate acquisition in the difference coordinate acquisition part of the coordinate compression apparatus of Example 1. FIG. 3 is a conceptual diagram illustrating an example of data compression processing executed by a compressed coordinate set output unit of the coordinate compression apparatus according to the first embodiment. The figure showing an example of the hardware constitutions in the coordinate compression apparatus of Example 1. 7 is a flowchart illustrating an example of a process flow in the coordinate compression apparatus according to the first embodiment. Conceptual diagram for explaining the characteristics of a coordinate set acquired in the coordinate compression apparatus according to the second embodiment. The figure showing an example of the functional block in the coordinate compression apparatus of Example 2. 7 is a flowchart illustrating an example of a process flow in the coordinate compression apparatus according to the second embodiment. The figure showing an example of the functional block in the route search apparatus of Example 3. A flowchart showing an example of the flow of processing in a route search device of Example 3. A conceptual diagram showing an example of a navigation system of Example 4. The figure showing an example of the functional block of each apparatus which comprises the navigation system of Example 4. FIG. A flowchart showing an example of a flow of processing in a navigation system of Example 4.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments, and can be implemented in various modes without departing from the spirit of the present invention.

  In the first embodiment, claims 1, 2, 6, and 7 will be mainly described. In the second embodiment, claims 3 and 8 will be mainly described. In the third embodiment, claims 4 and 9 will be mainly described. In the fourth embodiment, claims 5 and 10 will be mainly described.

Example 1
<Overview>
FIG. 1 is a conceptual diagram for explaining an example of coordinate group compression processing in the coordinate compression apparatus of the present embodiment. For example, in order for the user α to introduce a favorite restaurant to the friend β, the restaurants A, B, C, D, E, and F on the map data are specified as shown in FIG. Then, the user α uses the coordinate compression apparatus of the present embodiment to take the difference between the latitude and longitude values indicating the positions of the restaurants A to F as shown in FIG. For example, the size of the data to be transmitted is compressed to about 20 percent, and the compressed data is transmitted to the terminal of the user β.

  In this way, the user α can tell the friend β the recommended restaurant location with a lighter data size than usual.

<Functional configuration>
FIG. 2 is a diagram illustrating an example of functional blocks in the coordinate compression apparatus of the present embodiment. Note that the functional blocks of the coordinate compression apparatus described below can be realized as hardware, software, or both hardware and software. Specifically, if a computer is used, a CPU, a main memory, a bus, or a secondary storage device (a hard disk, a non-volatile memory, a storage medium such as a CD or a DVD, a read drive for the medium, etc.), information Input devices used for input, printing equipment, display devices, other hardware components such as external peripheral devices, interfaces for external peripheral devices, communication interfaces, driver programs for controlling these hardware, Other examples include application programs and user interface applications.

  Then, by CPU processing according to the program developed on the main memory, the data input from the input device or other interface and held in the memory or hard disk is processed and stored, An instruction for controlling the software is generated. In addition, the present invention can be realized not only as a coordinate compression apparatus but also as a method. A part of the invention can be configured as software. Furthermore, a software product used for causing a computer to execute such software and a recording medium in which the product is fixed to a recording medium are naturally included in the technical scope of the present invention (the same applies throughout the present specification). Is).

  As shown in FIG. 2, the “coordinate compression device” (0200) of the present embodiment includes a “coordinate group reception unit” (0201), a “reference coordinate selection unit” (0202), and “difference coordinate acquisition”. Part "(0203) and" compressed coordinate set output part "(0204).

  The “coordinate group accepting unit” (0201) has a function of accepting a coordinate group by taking a plurality of coordinates representing a position on the map as a set. For example, the CPU (central processing unit), main memory, I / O (input / input) Output), a coordinate group reception program, and the like. “Coordinates” refers to numerical information for indicating a position. For example, in addition to latitude and longitude information, numerical information for specifying a position that is specially set in accordance with the present invention may be used. Further, “a set of a plurality of coordinates” means that a plurality of coordinate points indicated by position information such as latitude and longitude information are grouped together to form a set.

  Then, the “coordinate group reception unit” specifically presents a map to the user terminal, for example, as described above, and in response to an operation input for designating a plurality of points on the map by the user, the plurality of points The configuration of accepting the latitude / longitude information as a coordinate set is included. Or the structure which refers the table data which linked | related the landmark name and the latitude longitude information of the position with the landmark, and receives the latitude longitude information of the some landmark name input by the user as a coordinate group is also mentioned. Also, based on position measurement information using GPS (Global Positioning System) and position measurement information based on other position measurement methods (for example, position measurement methods using wireless LAN spots, mobile phone base station specific position information, etc.). In addition, a configuration for acquiring a set of coordinates such as a plurality of latitude / longitude information is also available.

  Further, as described later in the third embodiment, a plurality of pieces of latitude / longitude information representing a route obtained as a result of route search may be accepted as a coordinate set. Of course, a set of a plurality of coordinates may be received by other configurations other than the above.

  Thus, the coordinate compression apparatus according to the present embodiment acquires numerical information indicating a plurality of coordinates. The coordinate information mainly indicates a plurality of points included on a map in a predetermined range, and is often composed of a set of coordinate information of adjacent points. Therefore, the high-order digits are approximate, and a high data amount compression can be performed.

  The “reference coordinate selection unit” (0202) has a function of selecting a reference coordinate from a plurality of coordinates included in the acquired coordinate set, and is realized by, for example, a CPU, a main memory, a reference coordinate selection program, or the like. Can do. Specific examples of the method for selecting the reference coordinates include a method of selecting, as the reference coordinates, the coordinate point received first / last in the coordinate group. In this case, for example, regarding the coordinate (latitude) set of “35.675287, 35.675440, 35.675754”, the first “35.675287” is selected as the reference coordinate.

  In addition to a selection method in which one coordinate is fixed as a reference coordinate, there is a method in which the coordinate of the previous term is selected as a reference coordinate in a stepwise (relative) manner. In this case, it is preferable that the reference coordinate selection unit has “relative selection means” (not shown). The “relative selection means” has a function of selecting coordinates to be expressed as difference coordinates as reference coordinates. Specifically, for example, with respect to the coordinate (latitude) set of “35.675287, 35.675440, 35.675741” described above, “35.675287” before the second “35.675440” is set. Select as reference coordinates. For the third “35.6757571”, the preceding “35.675440” is selected as the reference coordinate.

  As described above, the reference coordinates are fixed / relatively selected by the reference coordinate selection unit, and a plurality of coordinates included in the coordinate set are set as difference values from the reference coordinates by the next difference coordinate acquisition unit. Can be represented.

  The “difference coordinate acquisition unit” (0203) has a function of performing a difference calculation between the reference coordinates included in the coordinate set and other coordinates and acquiring the other coordinates as difference coordinates, for example, a CPU, a main memory, It can be realized by a difference coordinate acquisition program or the like. Specifically, as shown in FIG. 3A, for example, a coordinate (latitude) set of “35.675287, 35.675440, 35.675741, 35.676091,. The first “35.675287” was selected as the reference coordinate. Then, the difference coordinate acquisition unit calculates a difference value “35675287, +153, +454, +804,...” Between the other coordinates and the reference coordinate, and acquires it as a difference coordinate.

  Further, as shown in FIG. 3B, for example, when the coordinates of the previous term are selected in a stepwise manner as the reference coordinates, the difference coordinate acquisition unit uses “35675287, +153, +301, +350,. "Is calculated and obtained as difference coordinates.

  In this way, the data bit amount can be reduced by expressing the coordinate group as a difference from the reference coordinate. Furthermore, in this embodiment, since it is a set of coordinates that mainly indicate a plurality of points included on a map in a predetermined range, the upper digits such as latitude and longitude are approximated, resulting in high data compression. To do.

  In the above example, the first coordinate is expressed as an 8-digit latitude and longitude value as it is, not as a difference, but the number of digits is reduced by the following configuration to reduce the data amount. Also good. That is, in the reference coordinate selection unit, for example, in the case of Japan, a predetermined coordinate such as a latitude / longitude origin (35.3929157, 139.4428875) in Azabudai, Minato-ku, Tokyo is selected as an absolute reference coordinate. In the above-described example, the first coordinate expressed as an 8-digit latitude / longitude value is displayed as a difference value with respect to the absolute reference coordinate in either case of fixed / relative as well as Japan. A code “01” or the like for identifying the absolute reference coordinates is added. Thus, although it is necessary to hold the table data indicating the relationship between the identification code and the absolute reference coordinate on the expanding side, the number of digits of the first coordinate can be reduced. Furthermore, the data compression rate can be increased.

  Also, the absolute reference coordinates may be provided by dividing the region into smaller units, such as the absolute reference coordinates of Tokyo and the absolute reference coordinates of Kanagawa Prefecture. In that case, it is preferable that a suitable coordinate is selected from a plurality of absolute reference coordinates in accordance with GPS positioning information, user input information, or the like.

  The “compressed coordinate set output unit” (0204) has a function of outputting, as a set, a reference coordinate and a differential coordinate that are not represented as differential coordinates, as a compressed coordinate set corresponding to the coordinate set that has received this coordinate set, For example, it can be realized by a CPU, a main memory, a compressed coordinate set output program, or the like.

  In addition, a predetermined bit data amount compression can be realized by expressing a plurality of coordinates included in the coordinate group as a difference value from the reference coordinate as described above. You may comprise so that another data compression process with respect to the coordinate group represented by the value may further be performed. Specifically, for example, as shown in FIG. 4, first, the difference value to which a plus or minus sign is attached is converted into an absolute value, and further a binary number conversion process is performed. For the binary value after conversion, the sign bit indicating the plus or minus sign of the value before the above-described absolute value processing is set to, for example, “1” if it is positive, “0” if it is negative, and the binary value. Append to the end of.

Next, the numerical value sequence is divided in units of 5 bits, and “0” is added to the unit that forms one coordinate information in combination with the next 5 bits unit, and the end of one coordinate information is 5 bits. "1" is added to (if one coordinate information is expressed by latitude and longitude, "1" may be added to the end of each latitude and longitude). Then, the binary value in 6-bit units is converted into a 64-(= 2 ⁶ ) -ary value that can represent 6-bit data with one character.

  Through the above processing, the latitude / longitude information indicating the six points can be expressed by 32 character strings such as “482sitgkC2MViBc5ARmZGVqpglEDmtUb”. Therefore, in this case, the data size can be compressed to about 20%.

  Of course, the compressed coordinate set compressed and output by the process of the coordinate compression apparatus of the present embodiment can be easily restored by performing a decompression process opposite to the above-described compression process.

<Hardware configuration>
FIG. 5 is a schematic diagram illustrating an example of the configuration of the coordinate compression apparatus when the functional components described above are realized as hardware. The operation of each hardware component in the coordinate group data amount compression processing will be described with reference to FIG.

  As shown in this figure, the coordinate compression device is a reference coordinate selection unit, a difference coordinate acquisition unit, and a compression coordinate set output unit, and also executes a “CPU” (0501) for executing various other arithmetic processes, Memory ”(0502). Also, a “flash memory” (0503) that stores and holds various data and programs, and an “I / O” (0504) that is a coordinate group receiving unit are provided. They are connected to each other via a data communication path such as a “system bus” to transmit / receive information and process information.

  A program is read out to the “main memory”, and the “CPU” refers to the read out program and executes various arithmetic processes according to the procedure indicated by the program. In addition, a plurality of addresses are assigned to each of the “main memory” and “flash memory”, and in the calculation processing of the “CPU”, the addresses are specified and accessed to store the data. It is possible to perform arithmetic processing using.

  Here, when a set of a plurality of coordinates (latitude and longitude information, etc.) specified according to the user input result or the route search result is acquired via “I / O”, the “CPU” follows the coordinate set reception program. These coordinates are stored in address 1 of the “main memory”. Subsequently, the “CPU” interprets the reference coordinate selection program, and selects, for example, the first acquired coordinate as the reference coordinate in the coordinate set stored in the “main memory” according to the interpretation result. , And stored in address 2 of “main memory”. In this selection process, as described above, one coordinate may be fixedly selected as a reference coordinate, or in order to obtain a difference in coordinates in a stepwise manner, the coordinates of the previous term are sequentially used as reference coordinates. It is good also as processing to choose. If the coordinates are indicated by latitude and longitude, the reference coordinates are selected for each latitude and longitude. Then, the “CPU” interprets the difference coordinate acquisition program and, according to the interpretation result, calculates the difference value between the fixed / relatively selected reference coordinate and the next coordinate for each of the latitude and longitude. And is stored in address 3 of the “main memory”.

  After that, the “CPU” interprets the compressed coordinate group output program, and converts, for example, the first reference coordinate value and the difference coordinate value stored in the “main memory” into absolute values according to the interpretation result. To do. Subsequently, a sign bit indicating a plus or minus sign before the absolute value is added to the converted binary value, and the numeric string is divided into 5-bit units. Then, “0” is added to the unit that forms one coordinate information in combination with the next 5-bit unit, and “1” is added to the 5-bit unit that ends the one coordinate information. Then, the binary value in 6-bit units is converted into a hexadecimal value such as “482 sites...” And stored in address 4 of “main memory”.

  Then, the data of the compressed coordinate group whose data amount is greatly reduced in this way can be transmitted to another terminal device or the like without taking time.

<Process flow>
FIG. 6 is a flowchart illustrating an example of a processing flow in the coordinate compression apparatus of the present embodiment. Note that the steps described below, may be a step performed by each hardware configuration of the above-mentioned computer, recorded on a medium, a process step of the program for controlling the computer It doesn't matter.

  As shown in this figure, first, a plurality of coordinates representing positions on a map specified by, for example, user input or route search processing are taken as a set, and the coordinate set is received via I / O ( Step S0601). Subsequently, for example, the first acquired coordinate or the like is selected as a reference coordinate from a plurality of coordinates included in the acquired coordinate set (step S0602), and the difference from the reference coordinate of other coordinates included in the coordinate set is determined. The value is calculated and acquired as a difference coordinate representing the other coordinate (step S0603). As described above, one coordinate selected in step S0602 may be fixedly used as the reference coordinate. As shown in this figure, every time a difference coordinate is acquired for one coordinate in step S0603, A configuration may be adopted in which the coordinates of the previous term are reselected as reference coordinates in order to take the difference.

  Then, with respect to a set of reference coordinates and difference coordinates not represented as difference coordinates, for example, the above-described absolute value conversion processing, binary number conversion processing, sign bit addition processing, 5-bit division processing, and hexadecimal conversion Processing is performed to output a compressed coordinate set with a reduced data amount (step S0604).

<Simple explanation of effect>
As described above, the coordinate compression apparatus according to the present embodiment can reduce the data bit amount by expressing the coordinate group as a difference from the reference coordinate. Furthermore, in this embodiment, since it is a set of coordinates that mainly indicate a plurality of points included on a map in a predetermined range, the upper digits such as latitude and longitude are approximated, resulting in high data compression. To do.

  Therefore, for example, even in a communication type navigation system via a relatively low-speed network such as a mobile phone network, the coordinate set can be transmitted to the client terminal at a speed that does not cause stress.

<< Example 2 >>
<Overview>
The present embodiment is a coordinate compression apparatus characterized in that the coordinate set received by the coordinate set receiving unit is a plurality of coordinate points for indicating a route on the map based on the above embodiment. As shown in FIG. 7, a plurality of coordinate points a to d indicating a route connecting a certain point A to another point B are “close” and “continuous”. Therefore, if the coordinate of the previous term is selected as the reference coordinate to take the difference, and the relative difference is taken, the difference value takes a relatively small value, and high compression efficiency can be realized. Condition.

<Functional configuration>
FIG. 8 is a diagram illustrating an example of functional blocks in the coordinate compression apparatus of the present embodiment. As shown in this figure, the “coordinate compression device” (0800) of the present embodiment is based on the above-described embodiment, based on the “coordinate group reception unit” (0801), the “reference coordinate selection unit” (0802), A “difference coordinate acquisition unit” (0803), a “compressed coordinate set output unit” (0804), and a “relative selection unit” (0805). Note that a detailed description of these components is omitted since it has been described in the above embodiment.

  The feature points of the coordinate compression apparatus of the present embodiment are that the coordinate group receiving unit further includes a “route group receiving unit” (0806), and the reference coordinate selecting unit further includes an “adjacent coordinate selecting unit” (0807). It is a point to have.

  The “route set receiving means” (0806) has a function of receiving a plurality of coordinates as a route set in order to express a route on a map as a line in which a plurality of coordinates are adjacent to each other. Or a main memory, an I / O, a route group reception program, or the like. A “route” refers to a line on a map that indicates a travel route such as a road connecting a point to another point. Since the route is a line as described above, the set of coordinate points representing the route is “close” and “continuous”.

  The “adjacent coordinate selection means” (0807) has a function of always selecting, as a reference coordinate, a coordinate adjacent to a coordinate to be calculated by the difference coordinate acquisition unit from a plurality of coordinates included in the route set. For example, it can be realized by a CPU, a main memory, an adjacent coordinate selection program, or the like. Since the coordinate set of the route is “continuous” as described above, basically, when the difference between the adjacent points is taken, the difference value is smaller than the difference value between the non-adjacent points. It becomes.

  Therefore, the coordinate compression apparatus of the present embodiment can compress the coordinate set with higher compression efficiency.

<Process flow>
FIG. 9 is a flowchart illustrating an example of a processing flow in the coordinate compression apparatus of the present embodiment. The steps shown below may be steps executed by each hardware configuration of the computer as described above, or processing steps that constitute a program for controlling the computer that is recorded on a medium. It doesn't matter.

  As shown in this figure, first, in order to express a route on a map specified by, for example, user input or route search processing as a line in which a plurality of coordinates are adjacent to each other, the plurality of coordinates are routed. The set is accepted via I / O or the like (step S0901). Subsequently, from among the plurality of coordinates included in the acquired route set, for example, the first acquired coordinate or the like is selected as the reference coordinate (step S0902), and the second coordinate adjacent to the reference coordinate and the reference coordinate are selected. The difference value is calculated to obtain a difference coordinate representing the second coordinate (step S0903).

  Next, using the second coordinate as the reference coordinate, the difference value of the third coordinate adjacent to the second coordinate point is calculated, and the difference coordinate representing the third coordinate is obtained. Then, this process is repeated until the coordinates included in all the route groups are executed (step S0904).

  Then, with respect to a set of reference coordinates and difference coordinates not represented as difference coordinates, for example, the above-described absolute value conversion processing, binary number conversion processing, sign bit addition processing, 5-bit division processing, and hexadecimal conversion Processing, etc. is performed, and the compressed coordinate set with the reduced data amount is output (step S0905).

<Simple explanation of effect>
As described above, the coordinate compression apparatus according to the present embodiment can obtain a difference from an adjacent point with respect to a “continuous” coordinate set indicating a route. Therefore, the coordinate compression apparatus of the present embodiment can compress the coordinate set with higher compression efficiency.

Example 3
<Overview>
The present embodiment is a route search apparatus in which the coordinate compression apparatus of the above embodiment is incorporated in hardware or / and software.

<Functional configuration>
FIG. 10 is a diagram illustrating an example of functional blocks in the route search apparatus according to the present embodiment. As shown in this figure, the “route search device” (1000) of the present embodiment includes the coordinate compression device of the second embodiment, and therefore, the “coordinate group receiving unit” (1001) and “reference coordinate selection”. Part "(1002)," difference coordinate acquisition part "(1003)," compressed coordinate set output part "(1004)," relative selection means "(1005), and" route set acceptance means "(1006) , “Adjacent coordinate selection means” (1007). Note that a detailed description of these components is omitted since it has been described in the above embodiment.

  The route search apparatus according to the present embodiment further includes a “point information acquisition unit” (1008), a “route search unit” (1009), and a “route group output unit” (1010).

  The “point information acquisition unit” (1008) has a function of acquiring point information indicating a plurality of points, and can be realized by a CPU, a main memory, an I / O, a point information acquisition program, and the like. “Point information” refers to information indicating a point, and includes, for example, latitude / longitude information, coordinate information indicating a position on a map, or a landmark name or an address name associated with the point information. And this point information acquisition part is specifically, like a normal route search apparatus, for example according to information, such as positioning information by GPS, designation input of a point on a map and a landmark name by a user, etc. That is, the point information indicating the point is acquired.

  The “route search unit” (1009) has a function of searching for a route connecting the plurality of points based on the acquired point information, and can be realized by, for example, a CPU, a main memory, a route search program, or the like. Specifically, as in a normal route search device, for example, a route connecting a plurality of points is searched using a Dijkstra method or another route search algorithm.

  The “route set output unit” (1010) has a function of outputting a plurality of coordinates indicating the searched route to the route set receiving means. For example, a CPU, main memory, I / O, route set output program, etc. Can be realized. In this way, in the route search device of this embodiment, for example, a route connecting a plurality of points designated by the user is searched, and the data amount of a route set including a plurality of continuous coordinates indicating the search result is obtained. It is possible to compress at a high compression rate.

<Process flow>
FIG. 11 is a flowchart illustrating an example of a processing flow in the route search apparatus according to the present embodiment. The steps shown below may be steps executed by each hardware configuration of the computer as described above, or processing steps that constitute a program for controlling the computer that is recorded on a medium. It doesn't matter.

  As shown in this figure, first, a plurality of pieces of point information are acquired in accordance with, for example, a designation input from a user via a GUI (step S1101). For example, according to an algorithm based on the Dijkstra method, A route that connects a plurality of coordinates and is expressed as a line in which a plurality of coordinates are continuously adjacent to each other is searched (step S1102). Then, a plurality of coordinates indicating the route specified by the route search are output as a route set (step S1103). Then, the output route set is acquired (step S1104), for example, the first acquired coordinate or the like is selected as the reference coordinate (step S1105), the second coordinate adjacent to the reference coordinate, the reference coordinate, To obtain a difference coordinate representing the second coordinate (step S1106).

  Next, using the second coordinate as the reference coordinate, the difference value of the third coordinate adjacent to the second coordinate point is calculated, and the difference coordinate representing the third coordinate is obtained. Then, this process is repeated until the coordinates included in all the route groups are executed (step S1107).

  Then, with respect to a set of reference coordinates and difference coordinates not represented as difference coordinates, for example, the above-described absolute value conversion processing, binary number conversion processing, sign bit addition processing, 5-bit division processing, and hexadecimal conversion Processing, etc. is performed, and a compressed coordinate set with a reduced data amount is output (step S1108).

<Simple explanation of effect>
As described above, the route search device of the present embodiment searches for a route connecting a plurality of points specified by the user, for example, and the data amount of a route set composed of a plurality of continuous coordinates indicating the search result is obtained. It is possible to compress at a high compression rate.

Example 4
<Overview>
In this embodiment, as shown in FIG. 12, the route search apparatus described in the above embodiment and a compressed coordinate set indicating a request for route search to the route search apparatus and a response (search result) are provided. A navigation system characterized by comprising (a plurality of) receiving terminal devices.

<Functional configuration>
FIG. 13 is a diagram illustrating an example of a functional block of each device constituting the navigation system of the present embodiment. As shown in this figure, the navigation system of the present embodiment includes a “route search device” (1300) and a “terminal device” (1310).

  Then, the “route search device” includes a “coordinate group reception unit”, a “reference coordinate selection unit”, a “difference coordinate acquisition unit”, a “compressed coordinate group output unit” (not shown) based on the above embodiment, It has “relative selection means”, “route set accepting means”, “adjacent coordinate selection means”, “point information acquisition section”, “route search section”, and “route set output section”. Note that a detailed description of these components is omitted since it has been described in the above embodiment.

  The route search apparatus further includes a “point information receiving unit” (1301) and a “compressed coordinate set reply unit” (1302).

  The “point information receiving unit” (1301) has a function of receiving the point information transmitted from the terminal device, and can be realized by a CPU, a main memory, an I / O, a point information receiving program, and the like. Specifically, for example, GUI data including a map for inputting point information is transmitted to the terminal device via a communication network such as the Internet. And the point information input using the said GUI and transmitted as an HTTP request is received.

  The “compressed coordinate set reply unit” (1302) has a function of returning a compressed coordinate set based on the received point information to the terminal device. For example, the CPU, main memory, I / O, compressed coordinate set reply program, etc. Can be realized. Specifically, a route search is executed from the point information received by the process described in the above embodiment, and a process of generating a compressed coordinate set for the set of coordinates indicating the searched route is executed. For example, as a response to the HTTP request including the point information received by the point information receiving unit, the generated compressed coordinate group is returned to the terminal device that has transmitted the request.

  In addition, if information specifying a reply destination terminal device is input in advance as a reply destination of the compressed coordinate set, for example, using the GUI for inputting the point information, another terminal according to the reply destination designation information Processing may be performed using the device as a reply destination.

  This completes the description of the configuration requirements of the “route search device” that constitutes the navigation system of the present embodiment. Next, a “terminal device” that also constitutes the navigation system of the present embodiment will be described with reference to FIG. The “terminal device” refers to a device used by an end user (a device used by all users in a P2P type system), such as a desktop PC (personal computer), a notebook PC, a smartphone, a mobile phone, and the like. .

  As shown in FIG. 13, the “terminal device” (1310) includes a “point information input receiving unit” (1311), a “point information transmitting unit” (1312), and a “compressed coordinate set receiving unit” (1313). ), An “extension unit” (1314), and a “restoration unit” (1315).

  The “point information input receiving unit” (1311) has a function of receiving an input of point information, and examples thereof include a CPU, a main memory, an input device, and a point information input receiving program including a GUI. Note that “point information” refers to information indicating a point, for example, information indicating points such as a departure point, a destination, and a transit point in route search. In this point information input receiving unit, specifically, for example, a method of displaying a map image on the display of the terminal device and receiving the cursor position on the map designated by the user with the input device as the input point information is cited. It is done. Alternatively, a method of selecting and inputting a landmark name or address name such as “Tokyo Station” using a pull-down menu or a free input using a text input field may be used.

  The “point information transmission unit” (1312) has a function of transmitting the received point information to the route search device, and can be realized by, for example, a CPU, a main memory, an I / O, a point information transmission program, or the like.

  The “compressed coordinate set receiving unit” (1313) has a function of receiving a compressed coordinate set returned according to the transmitted point information. For example, the CPU, main memory, I / O, compressed coordinate set receiving program, etc. Can be realized.

  The “decompression unit” (1314) has a function of decompressing the received compressed coordinate set to the original reference coordinate and differential coordinate set, and can be realized by, for example, a CPU, a main memory, an expansion program, or the like. Specifically, for example, if the processing is the reverse of the processing described in the compressed coordinate set output unit of the above embodiment, that is, if the compressed coordinate set is represented by a hexadecimal value, (1) conversion to a binary value Processing, (2) termination determination processing referring to the last sign in 6-bit units, (3) deletion processing of sign bit indicating positive or negative, (4) conversion processing to decimal value, (5) deletion A plus or minus sign addition process according to the sign bit may be performed. Then, by this decompression process, for example, a compression coordinate set of “482sitgkC2MViBc5ARmZGVqpglEDmtUb” is converted into reference coordinate and difference value data (not represented as difference coordinates) such as “356675287, +153, +301, +350,. That's it.

  The “restoring unit” (1315) has a function of restoring a plurality of coordinate sets from a set of reference values and difference values, and can be realized by, for example, a CPU, a main memory, a restoration program, or the like. Specifically, a set of coordinates including a difference value of “35675287, +153, +301, +350,...” Is expressed as “35.675287, 35.675440, 35.675741, 35.676091,. All the points “” are restored to a set of coordinates represented by latitude and longitude.

  As described above, in the navigation system of the present embodiment, a plurality of coordinates indicating the route search result performed in response to the input reception from the terminal device can be easily converted as a compressed coordinate set with a reduced data amount via the Internet network or the like. Can be sent and received.

  It should be noted that, for example, when user A teaches user B the route, the terminal device that transmits the point information and the terminal device that expands and restores the compressed coordinate set returned based on the terminal information and displays it on a map or the like are separate. It may be a device. That is, in the navigation system of this embodiment, the terminal device of the user A transmits the point information to the route search device, and the compressed coordinate set returned as a result is transferred to the terminal device of the user B, where the decompression unit and the restoration unit It may be configured that the process is executed.

<Process flow>
FIG. 14 is a flowchart illustrating an example of a process flow in the navigation system of the present embodiment. The steps shown below may be steps executed by each hardware configuration of the computer as described above, or processing steps that constitute a program for controlling the computer that is recorded on a medium. It doesn't matter.

  As shown in this figure, first, when an input of a plurality of pieces of point information is received at the terminal device via a GUI or the like (step S1411), the terminal device transmits the plurality of pieces of point information received to the route search device. (Step S1412).

  When the route search device receives and acquires a plurality of pieces of point information transmitted from the terminal device (step S1401), for example, according to an algorithm based on the Dijkstra method, a plurality of coordinates connecting the plurality of points acquired are adjacent. A route expressed as a continuous line is searched (step S1402). And the said some coordinate which shows the route specified by the route search is output (step S1403), and it acquires (step S1404). Then, for example, the first acquired coordinate or the like is selected as the reference coordinate (step S1405), the difference value between the second coordinate adjacent to the reference coordinate and the reference coordinate is calculated, and the second coordinate is calculated. Is obtained (step S1406).

  Next, using the second coordinate as the reference coordinate, the difference value of the third coordinate adjacent to the second coordinate point is calculated, and the difference coordinate representing the third coordinate is obtained. Then, this process is repeated until the coordinates included in all the route groups are executed (step S1407). Then, with respect to a set of reference coordinates and difference coordinates not represented as difference coordinates, for example, the above-described absolute value conversion processing, binary number conversion processing, sign bit addition processing, 5-bit division processing, and hexadecimal conversion Processing, etc. is performed, and the compressed coordinate set with the reduced data amount is output (step S1408) and returned to the terminal device (step S1409).

  The terminal device receives the returned compressed coordinate set (step S1413). Then, expansion processing is performed on the received compressed coordinate set, for example, conversion processing from a hexadecimal value to a binary value, termination determination processing, code bit deletion processing, conversion to a decimal value, plus or minus sign addition A process etc. are performed and the coordinate group represented by a reference | standard coordinate and a difference is acquired (step S1414). Then, a plurality of coordinate sets representing positions on the map are restored from the acquired reference coordinates and differences (step S1415).

<Simple explanation of effect>
As described above, with the navigation system of this embodiment, a plurality of coordinates indicating the route search result performed in response to the input reception from the terminal device can be easily converted as a compressed coordinate set with a reduced data amount via the Internet network or the like. Can be sent and received.

0200 Coordinate compression device 0201 Coordinate group reception unit 0202 Reference coordinate selection unit 0203 Difference coordinate acquisition unit 0204 Compressed coordinate group output unit

Claims (10)

A coordinate group accepting unit that accepts a coordinate group as a set of a plurality of coordinates representing a position on the map;
A reference coordinate selection unit for selecting a reference coordinate from a plurality of coordinates included in the acquired coordinate set;
A difference coordinate acquisition unit that performs a difference calculation between the reference coordinates included in the coordinate set and other coordinates, and acquires the other coordinates as a difference coordinate;
An absolute reference coordinate holding unit that holds absolute reference coordinates indicating predetermined coordinates in association with an identification code for identifying the absolute reference coordinates;
An absolute reference coordinate acquisition unit for acquiring the absolute reference coordinate and the identification code held in association with each other;
A second difference coordinate acquisition unit that performs a difference calculation between a reference coordinate included in the coordinate set and the absolute reference coordinate, and acquires the reference coordinate as a difference coordinate;
And the coordinate sets of which the one set the identification code and the total difference coordinates, the compression set of coordinates output unit for outputting as a compressed set of coordinates corresponding to the set of coordinates accepted at the reception portion,
A coordinate compression apparatus.   The absolute reference coordinate holding unit holds a plurality of absolute reference coordinates, and further holds a region holding means for holding the absolute reference coordinate further in association with region identification information indicating a region of a predetermined range including the position indicated by the absolute reference coordinates. Have
  The absolute reference coordinate acquisition unit includes an area-specific acquisition unit that acquires an absolute reference coordinate of an area including a coordinate set based on the received coordinate set and the held area identification information. The coordinate compression apparatus described in 1. The reference coordinate selection unit, as the reference coordinates, we have a relative selection means for selecting a plurality of coordinates included in the acquired coordinate set, in order to be a differencing specific difference operation,
The second difference coordinate acquiring unit, the coordinate compression apparatus according to claim 1 or 2 carried out only difference operation between the first selected reference coordinate the absolutely reference coordinates in the reference coordinate selection unit. The coordinate set accepting unit has a route set accepting unit for accepting the plurality of coordinates as a route set in order to express the route on the map as a line in which a plurality of coordinates are adjacent to each other.
The relative selectivity means of the reference coordinate selection unit sequentially selects the coordinates adjacent to the coordinates always the calculation target in the difference coordinate acquiring unit from a plurality of coordinates included in the route pair as the reference coordinates The coordinate compression apparatus according to claim 3 . A route search device including the coordinate compression device according to claim 4 ,
A point information acquisition unit for acquiring point information indicating a plurality of points;
A route search unit for searching for a route connecting the plurality of points indicated by the acquired point information;
A route pair output unit for outputting a plurality of coordinates indicating the searched route to the route pair accepting means,
Route search device having A navigation system comprising the route search device according to claim 5 and a terminal device,
The route search device is
A spot information receiving unit that receives the spot information transmitted from the terminal device and delivers the spot information to the spot information acquisition unit ;
Anda compression set of coordinates returning unit for returning to the terminal device a compression set of coordinates output from said coordinate compressing device based on the said received point information,
The terminal device is
A table data holding unit that holds table data that associates the identification code with its absolute reference coordinates;
A point information input receiving unit for receiving the input of the point information;
A point information transmission unit that transmits the received point information to the route search device;
A compressed coordinate set receiving unit that receives a compressed coordinate set returned according to the transmitted point information;
A decompression unit that decompresses the received compressed coordinate set to a set of original reference coordinates and difference coordinates based on the absolute reference coordinates specified using the identification code included in the compressed coordinate set as a key ;
A restoration unit for restoring a plurality of sets of coordinates from this set of reference coordinates and differential coordinates,
A navigation system. An operation method of a coordinate compression apparatus having an absolute reference coordinate holding unit for holding an absolute reference coordinate indicating a predetermined coordinate in association with an identification code for identifying the absolute reference coordinate,
A coordinate set accepting step for accepting a coordinate set with a plurality of coordinates representing a position on the map as a set;
A reference coordinate selection step of selecting a reference coordinate from a plurality of coordinates included in the acquired coordinate set;
A difference coordinate acquisition step of performing a difference calculation between the reference coordinates included in the coordinate set and other coordinates, and acquiring the other coordinates as a difference coordinate;
An absolute reference coordinate acquisition step of acquiring the absolute reference coordinate and the identification code held in association with each other;
A second difference coordinate acquisition step of performing a difference calculation between the reference coordinates included in the coordinate set and the absolute reference coordinates, and acquiring the reference coordinates as a difference coordinate;
Coordinate sets of which the one set and the total difference coordinate with the identification code, a compression set of coordinates output step of outputting as a compressed set of coordinates corresponding to the set of coordinates accepted by the set of coordinates accepting step,
A method of operating a coordinate compression apparatus that causes a computer to execute.   The absolute reference coordinate holding unit holds a plurality of absolute reference coordinates, and further holds a region holding means for holding the absolute reference coordinate further in association with region identification information indicating a region of a predetermined range including the position indicated by the absolute reference coordinates. And having
  The absolute reference coordinate acquisition step is a step of acquiring an absolute reference coordinate of a region including the coordinate set based on the received coordinate set and the held region identification information. Operation method of coordinate compression apparatus.   The reference coordinate selection step is a step of selecting, as the reference coordinates, a plurality of coordinates included in the acquired coordinate set in order so as to be a stepwise difference calculation,
  The operation method of the coordinate compression apparatus according to claim 7 or 8, wherein the second difference coordinate acquisition step is a step of performing only a difference calculation between the reference coordinate first selected in the reference coordinate selection step and the absolute reference coordinate. . An operation method of a route search device including a coordinate compression device that operates according to the operation method of the coordinate compression device according to claim 9, and a table data holding unit that holds table data in which the identification code and its absolute reference coordinates are associated with each other. and a method of operating a terminal device including a method of operating a navigation system including,
In the operation method of the route search device,
The coordinate set accepting step is a step of accepting the plurality of coordinates as a route set in order to express a route on the map as a line in which a plurality of coordinates are adjacent to each other.
The reference coordinate selection step is a step of selecting, as a reference coordinate, a coordinate that is always adjacent to a coordinate to be calculated in the difference coordinate acquisition step from a plurality of coordinates included in the route set.
A point information acquisition step for acquiring point information indicating a plurality of points;
A route search step for searching for a route connecting the plurality of points based on the acquired point information;
A route set output step for outputting a plurality of coordinates indicating the searched route to the route set receiving step;
A point information receiving step for receiving the point information transmitted from the terminal device;
A compression set of coordinates reply step of the returned compression set of coordinates output by the operating method of the coordinate compressing device based on the said received point information to the terminal device, is performed in a further computer,
The operation method of the terminal device is:
A point information input receiving step for receiving point information input;
A point information transmission step of transmitting the received point information to the route search device;
A compressed coordinate set receiving step for receiving a compressed coordinate set returned according to the transmitted point information;
A decompression step of decompressing the received compressed coordinate set to a set of original reference coordinates and difference coordinates based on an absolute reference coordinate specified using an identification code included in the compressed coordinate set as a key ;
A restoration step of restoring a plurality of sets of coordinates from this set of reference coordinates and differential coordinates,
Of the navigation system that causes the computer to execute the operation.

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