JP5403921B2 - Large-scale map image generation / management device - Google Patents

Description

  The present invention relates to a technology for receiving a map image transmission request with a desired display setting from a client through a network such as the Internet or an intranet, generating a map image according to the display setting, and transmitting the map image to the client through the network.

  In this type of conventional technology, a map image is transmitted to a client by an image data map transfer method (Patent Document 1). That is, when the transmission server receives a map image transmission request with a desired display setting from the client, the map information system (GIS) is used to generate a map image corresponding to the display setting and send it to the client. The generated map image is displayed on the display system on the client side.

  In the technique of Patent Document 1, a technique of reusing a generated map image is also known (Non-Patent Document 1). In other words, the generated map image is divided and stored in the storage device of the server, and when the transmission request of the map image with the desired display setting is received from the client, it corresponds to the display setting in the storage device. If the divided map image to be stored is stored, the divided map image in the storage device is tiled to create a map image according to the display setting and transmit it to the client, while the storage device stores the map image in the storage device. If the divided map image corresponding to the display setting is not stored, a new map image corresponding to the display setting is generated using GIS, the map image is divided and stored in the storage device, and is stored in the client. Send.

Japanese Patent Laid-Open No. 2004-70174 First Item FIG. Ryuichi Tanaka, Yoichiro Izumi, Kazuki Iwane, Ushio Inoue (2007) Design and Implementation of High Interactive WebGIS Framework-TMAP2 by Asynchronous Communication, IEICE 18th Data Engineering Workshop Proceedings, DEWS2007B7-2

  In the technique of the above-mentioned Patent Document 1, each time a transmission request for a map image with a desired display setting is received from a client, a map image corresponding to the display setting is newly created using the GIS. It is generated and reuse of the generated map image is not considered. That is, every time a map image transmission request is received from a client, a new map image is generated using GIS, so that the load on the server on the transmission side is large and the response performance to the request from the client is degraded. There is.

  On the other hand, in the technique of Non-Patent Document 1 described above, the generated map image is divided and saved in a storage device, so that the generated map image is reused (that is, a request from a client). The response performance against is not deteriorated). However, in consideration of differences in display settings such as layer superposition order, there are a large number of map images that can potentially be generated, so there may be a large number of map images stored in the storage device. There is a problem that the storage capacity of the storage device cannot be effectively used.

  The present invention has been made to solve the above-mentioned problems. First, the reusability of the generated map image and the effective use of the storage capacity of the storage device for storing the generated map image are provided. The purpose is to provide a large-scale map image generation and management device that is compatible with performance. A second object of the present invention is to provide a large-scale map image generation / management apparatus that can cope with layer display control (change of layer display order) by storing a small number of map images.

In order to solve the above problems, a first aspect of the present invention, according to the display setting information transmitted client or al, a large map image generation and management system for generating a map image at the server, the client a display setting information communication means for receiving the display setting information of the pressurized et al, predetermined map DB: based on the map data stored in the (DB database, hereinafter the same), each layer image constituting the map image A map image generating unit that generates the image by dividing it into tiles, a map image combining unit that generates a map image that superimposes and synthesizes each layer image and sends it back to the client, and a map image generating unit that is newly generated by the map image generating unit For each layer image and the map image returned to the client, a directory classified for each scale, a directory for each scale, and a layer image type A plurality of directories are categorized according to the, and transmits the predetermined map image DB stored at composed stored rules directory of the map image to be sent back to the client, a map image is stored in the predetermined map image DB And a map image discarding unit for discarding the layer image and the map image stored in the predetermined map image DB in accordance with a predetermined discard rule.

According to the first aspect of the present invention, since the layer image and the map image are stored in the predetermined map image DB, the newly generated map image or the like can be reused and stored in the predetermined map image DB. Since the map image or the like is discarded according to a predetermined discard rule, the storage capacity of the predetermined map image DB can be used effectively. Thus, compatible with reuse of the map image or the like generated, and an effective use of the storage capacity of a storage device for storing a map image or the like.

Embodiment 1 FIG.
<Overall configuration>
FIG. 1 is a schematic configuration diagram of a map image transmission system including a large-scale map image generation / management apparatus according to the present invention.

  As shown in FIG. 1, the map image transmission system includes a map image transmission server 1 and a client side system (hereinafter referred to as a client system) connected to the map image transmission server 1 via a network (for example, the Internet or an intranet) 2. The map image transmission server 1 receives the display setting information 6 specifying the display setting of the map image from the client system 12 through the network 2, and the map image 10 is displayed according to the display setting information 6. The map image 10 is generated and transmitted to the client system 12 through the network 2.

  The client system 12 performs setting of the display setting information 6 by the user (initial display designation processing 12a), display of the map image 10 transmitted from the geographic information system server 4, and the like.

  The display setting information 6 includes, for example, information such as a display target layer, a layer superposition order, a map display range, and a display scale. The display target layer is information specifying the type of layer image (a layer image defining a road, a layer image defining a building, etc.) constituting a map image requested by the client (hereinafter referred to as a request target map image). It is. The layer superposition order is information that designates the superposition order of each layer image constituting the requested map image. The map display range is information specifying the display range of the requested map image. The display scale is information specifying the scale of the requested map image.

  The map image transmission server 1 includes a WEB server 3 that communicates with the client system 12 through the network 2, a geographic information system server 4 that generates a map image according to display setting information 6 from the client system 12, and a new generation of a map image And a DB server 5 having a map image DB 9 (DB: database, the same applies hereinafter) 8 and a map image DB 9 for storing the generated map image for reuse.

  The WEB server 3 manages the connection with the network 2 and transmits the display setting information 6 from the client system 12 to the geographic information system server 4 and is generated according to the display setting information 6 in the geographic information system server 4. The map image 10 is transmitted to the client system 12. When performing a large-scale WEB service, the WEB server 3 may include a load balancer for performing load distribution.

  The geographic information system server (GIS engine) 4 generates a map image and manages the generated map image (that is, saves and discards), and a map that defines a map image management rule. And image generation setting information 7. The map image generation setting information 7 is stored and provided in a predetermined storage device (not shown).

  The map image generation setting information 7 includes information on the size (division size), file format, storage rule, and discard rule of the map image when managing the map image.

  The large-scale map image generating / managing apparatus 11 uses the map data stored in the map DB 8 of the DB server 5 to newly display the map image stored in the map image DB or to set the display from the client system 12. The map image 10 according to the information 6 is generated, and the newly generated map image 10 is stored and managed in the map image DB 9 according to the map image generation setting information 7. More specifically, when a map image 10 is newly generated, each layer image constituting the map image 10 is first divided into tiles according to the size defined in the map image property setting information 7. By generating and superimposing these layer images, the map image 10 is newly generated in a state of being divided into tiles. When the newly generated map image 10 is stored in the map image DB 9, not only the map image 10 but also each layer image thereof is separately divided into tiles and defined in the map image property setting information 7. Are stored in the map image DB 9 in accordance with the file format and storage rules.

  Here, the hardware configuration of the map information system server 4 is, for example, as shown in FIG. 3, a CPU 31, a memory 32 in which a program defining processing operations of the large-scale map image generation / management apparatus 11 is stored, a map, and the like. An external storage device 33 that stores the image generation setting information 7, an input device 34, a display device 35, and a communication device 36 that communicates with the WEB server 3 and the DB server 5 are configured. The CPU 31 executes the processing operation of the large-scale map image generation / management apparatus 11 by executing the above-described program stored in the memory 32. The external storage device 33 is composed of, for example, a hard disk provided with a magnetic disk. The input device 34 includes a keyboard and a mouse, and is used for data input. The display device 35 displays the data processed by the CPU 31.

  The map DB 8 of the DB server 5 stores vector format or raster format map data and attribute data related to the map data. In the map image DB 9, map images (including layer images) are stored in a state of being divided into tiles according to the size, file format, and storage rules defined in the map image composition setting information 7.

  Here, the hardware configuration of the DB server 5 is, for example, as shown in FIG. 4, a CPU 51, a memory 52 for storing various programs such as a startup program for the CPU 51, and an external storage device for configuring the map DB 8 and the map image DB 9. 53, an input device 54, a display device 55, and a communication device 56 that communicates with the geographic information system server 4. The external storage device 53 is configured by, for example, a hard disk provided with a magnetic disk. A plurality of external storage devices 53 may be provided depending on the data capacities of the map DB 8 and the map image DB 9. The input device 54 includes a keyboard and a mouse, and is used for data input. When the DB server 5 is used only for storing the map DB 8 and the map image DB 9, the input device 54 may not be provided. The display device 55 displays the data processed by the CPU 51. When the DB server 5 is used only for storing the map DB 8 and the map image DB 9, the display device 55 may be omitted.

  FIG. 5 is a diagram illustrating a storage rule when a map image is stored in the map image DB 9.

  In the map image DB 9, the map image is managed on the file system based on the directory structure of FIG. That is, the map image DB 9 includes a route directory 100 that defines a route to the storage location of each stored map image as the uppermost directory. The root directory 100 includes a plurality of scale directories 200A, 200B,... Classified according to the display scale. For example, the scale directory 200A (200B) is a directory in which the map image of the display scale A (B) is stored. Any number of scale directories in this hierarchy can be defined.

  The scale directory 200A includes a plurality of layer directories 300a, 300b,... Classified according to the type of layer image. For example, the layer directory 300a is a directory in which a layer image defining a road in a map image at a display scale A (hereinafter referred to as a road layer image) is stored, and the layer directory 300b is a map image at a display scale A. Is a directory in which a layer image (hereinafter referred to as a building layer image) that defines a building is stored, and the layer directory 300c is a superimposed layer image (for example, a building layer on a road layer) obtained by combining and combining a plurality of layer images. Is a directory for storing (superimposed layer image obtained by superimposing and combining). The same applies to the other scale directories 200b,. Any number of layer directories in this hierarchy can be defined.

  In the layer directory 300a (300b), for example, road layer images (building layer images) are stored in a tiled state according to the size and file format defined in the map image generation setting information 7, and the layer directory In 300c, for example, a superimposed layer image obtained by superimposing a building layer image on a road layer image is stored in a tiled state according to the size and file format defined in the map image generation setting information 7.

  The map image newly generated by being divided into tiles is composed of a display scale of the map image, and the map image is composed of a single layer image or a combination of a plurality of layer images. The map image DB 9 stores the map image DB 9 according to the directory structure shown in FIG.

  A plurality of directories (hereinafter referred to as tile directories) classified according to each tile area of the layer image divided into tiles may be added to the above directory structure. For example, each of the layer directories 300a, 300b,... May include a plurality of tile directories classified according to each tile area of the layer image in a state of being divided into tiles. As a result, the amount of the map image (layer image) stored in the lowermost directory can be reduced. As a result, the layer image used when generating the map image using the layer image stored in the map image DB 9 can be selected. The search speed for searching can be improved.

  Here, the file system is used for managing the map image (layer image) in the map image DB 9, but it may be managed in a binary format using a database management system.

  Next, based on FIG. 2, the outline | summary of operation | movement of this map image transmission system is demonstrated.

  When the client system 12 is activated by the user in step S1, the WEB server 3 is accessed from the client system 12, and in response to the access in step S2, the WEB server 3 transfers to the client system 12. The client system file is transmitted, and in step S3, the client system file is received and read by the client system 12. By this reading, the client system 12 is activated in step S4.

  In step S5, when the user performs initial display designation (that is, designation of a display position, a display target layer, a display scale, etc. for initial display of the map image) to the client system 12, in step S6. Based on the designation, display setting information 6 is created by the client system 12, and the display setting information 6 is transmitted to the geographic information system server 4 via the WEB server 4.

  Then, in steps S7 and S8, the large-scale map image generating / managing apparatus 11 of the geographic information system server 4 uses the map data stored in the map DB 8 of the DB server 5 or newly stored in the map image DB. By reusing the image, a map image (request target map image) according to the display setting information 6 is generated.

  That is, first, in step S7, when the map image corresponding to the display setting information 6 or various layer images are not stored in the map image DB 9 by the large-scale map image generation / management apparatus 11, the map image is stored in the map DB 8. Using the map data, each layer image required for generating the requested map image is newly generated in a tiled state according to the size and file rule defined in the map image generation setting information 7 (Map image generation process). The generated layer images are temporarily stored in the map image DB 9 for reuse.

  In step S8, the layer image once saved is read out from the map image DB 9, and each layer image is superimposed and synthesized in accordance with the layer superposition order defined in the display setting information 6, and divided into tiles. In this state, a requested map image is generated (map image synthesis process). The requested map image divided into tiles is temporarily stored in the map image DB 9 for reuse, and then transmitted to the client system 12 via the WEB server 3.

  In step S7, when the map image or various layer images corresponding to the display setting information 6 are stored in the map image DB 9, the map image or various layer images stored in the map image DB 9 are reused. Then, the map image to be requested is generated in a state of being divided into tiles, and transmitted to the client system 12 via the WEB server 3.

  In step S9, the client system 12 receives the map image divided into tiles. In step S10, the received map image is subjected to map display processing such as tiling, and a predetermined display device. Is displayed.

  In step S11, the geographic information system server 4 discards the map image defined in the map image generation setting information 7 in order to effectively use the storage capacity of the map image DB 9 by the large-scale map image generation / management apparatus 11. Based on the definition, the map image (including the layer image) stored in the map image DB 9 is discarded.

<Functional Configuration of Large-Scale Map Image Generation / Management Device 11>
FIG. 6 is a diagram showing a functional configuration of the large-scale map image generation / management apparatus 11.

  As shown in FIG. 6, the large-scale map image generating / managing apparatus 11 includes a map image generating means 41, a map image synthesizing means 42, a map image discarding means 43, a map DB communication means 44, and a map image DB communication means. 45, a map image DB communication means 45, and a map image transmission means 47.

  The map DB communication means 44 communicates with the map DB 8 of the DB server 5 and receives map data from the map DB 8.

  The map image DB communication means 45 communicates with the map image DB 9 of the DB server 5 and transmits / receives a map image to / from the map image DB 9.

  The display setting information communication means 46 communicates with the WEB server 3 and receives the display setting information 6 from the WEB server 3.

  The map image generation means 41 is necessary for generating a map image according to the display setting information 6 acquired via the display information communication means 46 based on the map data acquired from the map DB 8 via the map DB communication means 44. A simple layer image (such as a road layer image or a building layer image) is generated in a tiled state according to the size and file format defined in the map image generation setting information 7. The generated layer image is stored in the map image DB 9 via the map image DB communication means 45 in accordance with a storage rule defined in the map image generation setting information 7 in order to reuse.

  The map image synthesizing unit 42 superimposes and synthesizes each layer image acquired from the map image DB 9 via the map image DB communication unit 45 in accordance with the layer superposition order of the display setting information 6 acquired via the display information communication unit 46. In order to reuse the generated map image 10 in a state of being divided into tiles, the map image DB communication is performed according to the storage rule defined in the map image generation setting information 7 in order to reuse the generated map image 10. It is stored in the map image DB 9 via the means 45.

  The map image transmission means 47 acquires the requested map image 10 stored in the DB server 5 via the map image DB communication means 45 and transmits the map image 10 to the client system 12 via the WEB server 3. .

  The map image discarding unit 43 discards the map image (including the layer image) to be discarded stored in the map image DB 9 via the map image DB communication unit 45 according to the discard definition defined in the map image generation setting information 7. To do.

  Next, the map image generation process (step S7 in FIG. 2) by the large-scale map image generation / management apparatus 11 will be described in detail with reference to FIGS.

  When the map image generation unit 41 acquires the map image generation setting information 7 and the display setting information 6 via the display setting information communication unit 46, the map of the request target is obtained based on the display setting information 6 in step S21. A layer image necessary for image generation is specified.

  Here, the display target layers of the display setting information 6 are a layer image Ga (for example, a road layer image) and a layer image Gb (for example, a building layer image), and the layer superposition order is to superimpose the layer image Gb on the layer image Ga. The superimposition order is used, the display target range is a predetermined range, and the display scale is a predetermined scale. In this case, based on this display setting information 6, the map image generation means 41 is a layer image that has a display target range as a predetermined region and a display scale as a predetermined scale as a layer image necessary for generating a request target map image. Ga and Gb are specified.

  In step S22, the map image generation means 41 first accesses the map image DB 9 via the map image DB communication means 45, and the layers divided into tiles corresponding to the specified layer images Ga and Gb. Images Ga-1 to Ga-n, Gb-1 to Gb-n or the above specified layer images Ga and Gb are superimposed and synthesized in the layer superposition order of the display setting information 6 (that is, the request target image). (Map image itself) It is confirmed whether the superimposed layer images Gab-1 to Gab-n divided into tiles corresponding to Gab are stored in the map image DB9.

  As a result of the confirmation, if the layer images Ga-1 to Ga-n, Gb-1 to Gb-n and the superimposed layer images Gab-1 to Gab-n are stored in the map image DB 9, the process proceeds to step S25. Proceed to finish the map image generation process. On the other hand, if the layer images Ga-1 to Ga-n, Gb-1 to Gb-n and the superimposed layer images Gab-1 to Gab-n are not stored in the map image DB 9 as a result of the confirmation, steps are performed. Proceeding to S23, the map data of the layer images Ga and Gb stored in the map DB 8 is acquired via the map DB communication means 44, and the specified layer images Ga and Gb are newly generated from the map data. At that time, the identified layer images Ga and Gb are respectively divided into tiles according to the size and file rule defined in the map image setting information 7, and the layer images Ga-1 to Ga-n and Ga-1 are divided. -Ga-n (new map image generation process).

  In step S24, the generated layer images Ga-1 to Ga-n and Gb-1 to Gb-n are mapped via the map image DB communication means 45 in accordance with the storage rules defined by the map image setting information 7. Temporary storage in the DB 9 (map image DB storage processing). Then, the process proceeds to step S25, and the map image generation process is terminated. In this way, the map image generation process (step S7 in FIG. 2) in the large-scale map image generation / management apparatus 11 is performed.

  Next, the map image synthesis process (step S8 in FIG. 2) by the large-scale map image generation / management apparatus 11 will be described in detail with reference to FIGS. Note that the setting of the contents of the display setting information 6 is the same as in the case of the map image generation process described above.

  When the map image synthesizing unit 42 acquires the map image generation setting information 7 and the display setting information 6 via the display setting information communication unit 46, the map image synthesizing unit 42 adds the display setting information 6 to the display target layer information in step S31. Based on this, it is confirmed whether there are two or more types of layer images necessary for generating the requested map image. Here, since the display target layers of the display setting information 6 are the layer images Ga and Gb, the map image synthesizing unit 42 confirms that there are two types of necessary layer images.

  As a result of the confirmation, if there are two or more types of the necessary layer images, the map image synthesizing unit 42 specifies the necessary layer images based on the display setting information 6 in step S32. Here, the necessary layer images are specified as two layer images Ga and Gb having a display target range as a predetermined region and a display scale as a predetermined scale.

  In step S33, the map image composition unit 42 corresponds to the superimposed layer image Gab formed by superimposing the identified layer images Ga and Gb on the map image DB 9 in accordance with the layer superposition order of the display setting information 6. It is confirmed whether or not the superimposed layer images Gab-1 to Gab-n) divided into shapes are stored. As a result of the confirmation, if the superimposed layer images Gab-1 to Gab-n are stored in the map image DB 9, the process proceeds to step S36, and the superimposed layer images Gab-1 to Gab-n are mapped to the map image DB communication means. 45 is acquired from the map image DB 9 via 45 and transmitted to the client system 12 via the map image transmission means 47 as the map image 10 to be requested.

  On the other hand, if the superimposed layer images Gab-1 to Gab-n are not stored in the map image DB 9 as a result of the confirmation in step S33, the process proceeds to step S34, where the map image synthesizing means 42 is the map image DB communication means. The layer images Ga-1 to Ga-n and Gb-1 to Gb-n divided into tile shapes corresponding to the layer images Ga and Gb specified in step S32 are acquired from the map image DB 9 via 45 and acquired. The layer images Ga-1 to Ga-n, Gb-1 to Gb-n are superimposed and synthesized in accordance with the layer superposition order of the display setting information 6 to generate superimposed layer images Gab-1 to Gab-n, and in step S35, The generated superimposed layer images Gab-1 to Gab-n are temporarily stored in the map image DB 9 via the map image DB transmission unit 45 for reuse. In step S36, the superimposed image composition unit 42 reads the temporarily stored superimposed layer images Gab-1 to Gab-n via the map image DB communication unit 45, and uses the map image transmission unit as a requested map image. 47 to the client system 12.

  As a result of the confirmation in step S31, when there is only one type of the above required layer image (for example, in the case of only the layer image Ga), it is not necessary to superimpose layer images (map image combining processing). Proceeding to step S36, the map image synthesizing unit 42 acquires the layer images Ga-1 to Ga-n divided into tiles corresponding to the layer image Ga from the map image DB 10 via the map image DB communication unit 45. The layer images Ga-1 to Ga-n divided into tiles are transmitted to the client system 12 through the map image transmission unit 47 as the map image 10 to be requested.

  In this way, the map image synthesis process (step S8 in FIG. 2) by the large-scale map image generation / management apparatus 11 is performed.

  Next, the map image discarding process (step S11 in FIG. 2) by the large-scale map image generating / managing apparatus 11 will be described in detail based on FIG. 6 and FIG.

  In step S41, the map image discard processing unit 43 is stored in the map image DB 9 of the DB server 5 via the map image DB communication unit 45 in accordance with the discard definition defined by the map image generation information 7 of the geographic information system server 4. Discard map images (including layer images).

  In the discard definition, for example, a method for discarding each map image is defined according to the file size of each map image (including layer images) stored in the map image DB 9. In this case, the file size of each map image is positioned as the map image generation cost, the predetermined file size is set as a threshold, and a map image having a file size equal to or larger than the threshold is defined as having a high map image generation cost. A map image with a file size less than that is defined as a low map image generation cost, and a map image with a high map image generation cost is discarded. Thereby, the map image generation cost of the geographic information system server 4 can be saved (that is, the storage capacity can be effectively used).

  The map image discard processing unit 43 discards the map image, for example, at a specified time such as the date and time, the day interval or the month interval set in the map image generation setting information 8, or at an arbitrary timing. .

  According to the map image transmission system configured as described above, since the newly generated map image 10 is stored in the predetermined map image DB 9, the newly generated map image 10 can be reused, and the predetermined map image Since the map image stored in the DB 9 is discarded according to a predetermined discard rule, the storage capacity of the predetermined map image DB 9 can be used effectively. Therefore, it is possible to achieve both the reuse of the generated map image and the effective use of the storage capacity of the storage device that stores the map image.

  When a map image according to the display setting information 6 is newly generated, a layer image (more specifically, a layer image divided into tiles) constituting the map image is generated, and each layer image is Since the map is stored in the predetermined map image DB 9 for reuse, a relatively small number of map images (layer images) can be stored, so that map images with different layer superposition orders can be generated and reusability can be improved.

  Further, since the map image (including the layer image) is saved in a tiled state, the reusability of the map image can be improved.

Embodiment 2. FIG.
In the first embodiment, the geographic information system server 4 and the DB server 5 are separated from each other. However, the map DB 8 and the map image DB 9 are stored in the storage device provided in the geographic information system server 4, and the DB server 5 is omitted. May be. This can reduce system construction costs.

Embodiment 3 FIG.
In the first embodiment, when a map image (including a layer image) is stored in the map image DB 9 as a discard rule defined in the map image generation setting information 7, the storage date and time (= generation date and time) of the map image is stored. If the number of map images stored in the map image DB9 exceeds the upper limit value, the upper limit value is set for the number of map images that can be stored in the map image DB9. You may employ | adopt the rule discarded in order from the map image with the oldest date. Thereby, it can prevent that the map image preserve | saved in map image DB9 overflows.

Embodiment 4 FIG.
In the first embodiment, each time a map image (including a layer image) stored in the map image DB 9 is reused as the discard rule defined in the map image generation setting information 7, information on the number of reuses is displayed. When an upper limit value is set for the number of map images that are associated with the map image and can be stored in the map image DB 9, and the number of map images stored in the map image DB 9 exceeds the upper limit value, A rule of discarding in order from the map image with the smallest number of reuses may be adopted. As a result, frequently used map images can be preferentially stored, and the number of new map image generations can be reduced.

1 is a schematic configuration diagram of a map image transmission system according to Embodiment 1. FIG. It is a figure explaining the operation | movement (communication processing from immediately after a client initial starting to map display) of the map image transmission system of FIG. 2 is a hardware configuration diagram of a geographic information system server 4. FIG. 2 is a hardware configuration diagram of a DB server 5. FIG. It is a figure explaining the file system structure of map image DB9. It is a figure explaining the function structure of the large-scale map image production | generation / management apparatus 11. FIG. It is a figure explaining the processing operation of the map image generation means. It is a figure explaining the process until it newly produces | generates and preserve | saves layer image Ga and Gb. It is a figure explaining the processing operation of the map image synthetic | combination means. It is a figure explaining the process until it produces | generates the request | requirement map image from the layer image (Ga, Gb, Gab) preserve | saved in map image DB9, and transmits to the client system 12. FIG. It is a figure explaining the processing operation of the map image discard means 43. FIG.

Explanation of symbols

  1 map image transmission server, 2 network, 3 WEB server, 4 geographic information system server, 5 DB server, 6 display setting information from client system 12, 7 map image generation setting information, 8 map DB, 9 map image DB, 10 Map image divided into tiles to be transmitted to the client system 12, 11 large-scale map image generation / management apparatus, 12 client system, 12a client side display setting information, 31 geographic information system server CPU, 32 geographic information system server memory, 33 Geographic information system server external storage device, 34 Geographic information system server input device, 35 Geographic information system server display device, 36 Geographic information system server communication device, 41 Map image generating means, 42 Map image synthesizing means, 43 Map image discarding means , 4 Map DB communication means, 45 Map image DB communication means, 46 Display setting information communication means, 47 Map image transmission means, 51 DB server CPU, 52 DB server memory, 53 DB server external storage device, 54 DB server input device, 55 DB server display device, 56 DB server communication device, 100 root directory, 200A, 200B scale directory, 300a-300c layer directory, 400a-400b Tile layer images stored in layer directories 300a-300c.

Claims (4)

According client or we sent display setting information, a large map image generation and management system for generating a map image at the server,
A display setting information communication means for receiving the display setting information of the client or al,
Map image generation means for generating each layer image constituting the map image by dividing it into tiles based on map data stored in a predetermined map DB (DB: database, the same applies hereinafter) ;
Map image synthesizing means for generating the map image for superimposing and synthesizing each layer image and returning it to the client;
For each layer image newly generated by the map image generation means and the map image returned to the client, the directory classified for each scale and the directory for each scale are further classified according to the type of the layer image. A predetermined map image DB to be stored with a storage rule composed of a plurality of directories and the map image directory to be returned to the client;
Map image DB communication means for transmitting a map image stored in the predetermined map image DB ;
Map image discarding means for discarding the layer image and the map image stored in the predetermined map image DB according to a predetermined discard rule;
A large-scale map image generating / managing apparatus comprising: The map image discarding unit has a file size of a layer image generated by the map image generation unit stored in the predetermined map image DB or a map image superimposed and synthesized by the map image synthesis unit. 2. The large-scale map image generating / managing apparatus according to claim 1, wherein the server discards a file having a file size larger than that . When the layer image generated by the map image generating means or the map image superimposed and synthesized by the map image synthesizing means is stored in the map image DB, information on the storage date is stored in the layer image or map image. An upper limit is set for the number of layer images or map images that are associated and can be stored in the map image DB,
The map image discarding means, when the number of layer images or map images stored in the map image DB exceeds the upper limit value, the server discards in order from the layer image or map image having the oldest storage date and time. The large-scale map image generation / management apparatus according to claim 1, wherein the apparatus is a large-scale map image generation / management apparatus. Each time the layer image generated by the map image generation unit stored in the map image DB or the map image superimposed and synthesized by the map image synthesis unit is reused, information on the number of reuses is displayed for the layer. An upper limit is set for the number of layer images or map images that are associated with images or map images and can be stored in the map image DB,
The map image discarding means, when the number of layer images or map images stored in the map image DB exceeds the upper limit value, the server discards in order from the layer image or map image with the smallest number of reuses. The large-scale map image generation / management apparatus according to claim 1.

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