CN113568995A

CN113568995A - Dynamic tile map making method based on retrieval conditions and tile map system

Info

Publication number: CN113568995A
Application number: CN202110699435.XA
Authority: CN
Inventors: 宋礼仪
Original assignee: Shujian Technology Suzhou Co ltd
Current assignee: Shujian Technology Suzhou Co ltd
Priority date: 2021-05-11
Filing date: 2021-06-23
Publication date: 2021-10-29
Anticipated expiration: 2041-06-23
Also published as: CN113568995B

Abstract

The invention discloses a dynamic tile map manufacturing method based on retrieval conditions and a tile map system, wherein the method comprises the following steps: s1, performing service access on the pre-created image map information database, and transmitting map browsing parameters as retrieval conditions; s2, retrieving a target image data list from the database according to the transmitted retrieval conditions; s3, analyzing the target image data list, and coding the analysis result and the personalized browsing parameters of the target image data list; s4, acquiring the corresponding tile from the specific storage area according to the encoding result, if the acquisition is successful, directly returning the acquired tile to the client, otherwise, executing S5-S6; s5, generating a corresponding tile according to the target image data list and the analysis result; and S6, writing the generated tiles and the coding results of the corresponding analysis results into a specific storage area, and returning. And the system performance is guaranteed by adopting a tile generation mechanism of filling and returning and a retrieval response mechanism of constructing cache key values.

Description

Dynamic tile map making method based on retrieval conditions and tile map system

Technical Field

The invention relates to the field of maps, in particular to a dynamic tile map manufacturing method based on retrieval conditions and a tile map system.

Background

When a traditional grid Tile Map Service (Web Map Tile Service, WMTS) is manufactured, grid data slicing processing is required to be performed first, data is organized in an ordered manner, and then Tile Map slicing processing and Map publishing are performed. The traditional processing mode can not meet the personalized browsing requirements of users, and slicing of raster data and storage of sliced data can consume a large amount of time and occupy a large amount of storage, and can not meet the requirements of continuous increase of user data and setting of personalized retrieval conditions.

The "user personalized browsing requirement" means that in a daily browsing grid tile map service, as the grid data of a user continuously accumulates and increases, the user wants to dynamically browse a certain area tile map service according to the self-defined retrieval conditions (product type, satellite, sensor, shooting time, and the like) and the arrangement mode and other conditions.

The accumulation of grid data of users will increase with time, and the grid data may contain development information such as production department, product grade, product type, shooting time, shooting satellite sensor type and the like besides basic position information. According to the traditional tile map making mode, N tile map services are needed to be made to possibly meet the personalized browsing requirements of users, so that management troubles are brought to the users, a large amount of time and storage space are wasted, and after data is updated, the corresponding services need to be sliced again, so that the daily requirements of the users cannot be met.

At present, a manufacturing method of a high-efficiency grid dynamic tile map which meets the retrieval conditions and personalized browsing requirements on the premise of ensuring the browsing efficiency is lacked.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a dynamic tile map making method based on retrieval conditions and a tile map system, and after data updating, a user can browse the grid tile map service of a corresponding area directly through the service according to the retrieval conditions set by the user without performing operations such as data slicing.

The general concept of the invention is as follows: inputting the spatial information, the path and the expansion information of the raster data into a database, creating indexes in the spatial fields and the attribute fields and generating a unique number identifier for each raster picture; when a user browses a certain area based on the retrieval conditions, calculating the area range corresponding to the tile, and acquiring a raster file list meeting the conditions from a database by combining with other retrieval conditions and a sorting mode; and calculating an MD5 code (or other unique codes) according to the returned data number list and personalized tile browsing parameters (tile format png, jpg, transparency, brightness and the like), acquiring cached pictures from a cache (a data database, an in-memory hash table and the like) according to the MD5 code, returning if the acquisition is successful, generating a new raster tile according to the image list and tile request information if the acquisition is unsuccessful, writing the new raster tile into the cache and returning. The specific technical scheme is as follows:

the invention provides a WMTS dynamic tile map manufacturing method based on retrieval conditions, which is executed by a tile map system, wherein the tile map system comprises a database and a tile generation module, and the WMTS dynamic tile map manufacturing method comprises the following steps:

s1, performing service access on the pre-created image map information database, and introducing map browsing parameters as retrieval conditions, wherein the retrieval conditions comprise the levels, line numbers and column numbers of tile requests, the corresponding ranges of calculation and attribute conditions for image file expansion, and the attribute conditions for image file expansion are one or more of image accessory information defined when the image map information database is pre-created;

s2, retrieving a target image data list from the image map information database according to the transmitted retrieval conditions;

s3, analyzing the target image data list, and combining the target image data list and the personalized browsing parameters to perform tile data coding to obtain a coding result;

s4, acquiring the corresponding tile from the specific storage area according to the encoding result, if the acquisition is successful, directly returning the acquired tile to the client, otherwise, executing S5-S6; wherein the specific storage area is different from the storage address of the image map information database;

s5, calling a tile generation module according to the target image data list and the analysis result thereof to generate a corresponding tile;

and S6, writing the generated tile and the coding result of the corresponding analysis result into the specific storage area, and returning the generated tile to the client.

Further, the step of invoking the tile generation module to generate the corresponding tile comprises:

s501, acquiring the number of image files in the target image data list, traversing the list to acquire an image file i, initializing i to 0, if i is less than the number of the files, executing S502, otherwise executing S507;

s502, if the coordinate system of the image file i is not consistent with the tile coordinate system, executing S503-S505,

otherwise, executing S506;

s503, converting an image external rectangle corresponding to a tile to be generated into a coordinate range corresponding to the image file i, and performing cutting operation on an area of the image file i in the converted image external rectangle range to obtain a first cut file;

s504, the first clipping file is put into a memory and memory file reprojection transformation is carried out on the first clipping file,

enabling the memory file coordinate system to be consistent with the tile coordinate system;

s505, performing clipping operation on the memory file after the reprojection transformation according to the external rectangular range of the image corresponding to the tile to be generated to obtain a second clipping file, filling the second clipping file into the corresponding cache region of the tile to be generated, and executing S507;

s506, performing clipping operation on the image file i according to the external rectangular range of the image corresponding to the tile to be generated to obtain a third clipping file, filling the third clipping file into the corresponding cache region of the tile to be generated, and executing S507;

s507, if all areas of the tile to be generated are filled, executing S508, otherwise, executing the self-adding and updating numerical value operation on the i, and returning to execute S501;

and S508, processing the filled file according to the personalized browsing parameters of the tiles, and compressing the file into a tile image.

Further, S1 is preceded by pre-creating a shadow map information database by:

s001, defining an accessory information category of image raster data stored in a database, and creating an index between the accessory information and the image raster data, wherein the accessory information category comprises one or more of file path, affine transformation information, space information, coordinate system information, satellite type, sensor type, product type, shooting time, production department information and arrangement mode;

and S002, reading the file list in the appointed directory, and inputting the image files in the file list and the corresponding auxiliary information into the database one by one.

Further, before the step S002, the method further includes:

judging whether the image file is the image data of the EPSG:4326, if so, recording the image file into a database, otherwise, converting the external rectangle of the corresponding image into the EPSG:4326 format and then recording the image file with the converted format into the database.

Further, in step S3, the personalized browsing parameter includes one or more of a tile format, a transparent color, a brightness, and an RGB color value, the target image data list and the personalized browsing parameter are formatted into a character string, and the character string after formatting is encoded.

And further, encoding the formatted character string in an encrypted or non-encrypted mode.

Further, step S2 further includes:

the transmitted retrieval conditions comprise spatial information of a hierarchy, a line number and a column number corresponding to the tile and other parameters, and a target image data list meeting the conditions of the other parameters is retrieved from the image map information database according to the spatial information.

Optionally, the specific storage area is a cache, a database, or a memory hash table.

In another aspect, the present invention provides a tile map system, comprising a server, a database, and a tile generation module, the server being configured to execute the following instructions:

Further, the server executes the following instructions after calling the tile generation module:

otherwise, executing S506;

The technical scheme provided by the invention has the following beneficial effects:

a. index information is established in space and other attribute columns of data, and corresponding image data meeting requirements are retrieved from a database according to a retrieval condition brought in real time and a browsing tile area, so that the aim of reducing performance bottleneck brought by the improvement of data quantity is fulfilled;

b. for areas browsed by other users, according to the file list corresponding to the tiles, the personalized tile parameter files construct cache key values, and the response time of the system is reduced under the condition that the requirements are met;

c. a mechanism of full filling and returning is adopted in the tile file generating process, so that the number of files opened in the tile generating process is reduced, IO access of a system is reduced, and the system performance is not limited by data volume under the condition of ensuring correct display vision;

d. the retrieval condition-based personalized tile map returning mechanism can not only guarantee the requirements of users for browsing tiles in a personalized manner, but also meet the retrieval requirements of the users.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a general flowchart of a WMTS dynamic tile mapping method provided by an embodiment of the present invention;

FIG. 2 is a flowchart of generating a tile according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or device.

In an embodiment of the present invention, a WMTS dynamic tile mapping method based on search criteria is provided, which is performed by a tile mapping system, the tile mapping system including a database and a tile generation module, and referring to fig. 1, the WMTS dynamic tile mapping method includes the following steps:

firstly, an image map information database is created in advance, then a target image is searched in the image map information database created in advance according to a search condition, unique coding is carried out on tile map data according to a target image list and personalized tile browsing parameters (tile formats png, jpg, transparency, brightness and the like), corresponding tiles are obtained from a cache according to the unique coding, if the unique coding is successful, the corresponding tile data are returned, otherwise, the tiles are generated to be returned to a client, and simultaneously, the generated tiles and the corresponding coding results are written into the cache so as to construct cache key values for newly generated tile files. The following is a detailed description of the various steps:

firstly, an image map information database is pre-created, and the method specifically comprises the following steps:

In this embodiment, before the image file is recorded into the database, it is further determined whether the image file is the image data of the EPSG:4326, if so, the image file is recorded into the database, otherwise, the external rectangle of the image corresponding to the image file is converted into the format of the EPSG:4326, and then the image file with the converted format is recorded into the database.

In addition, when new data are generated in the process of business production, namely data production and processing, the image files in the new data and the corresponding auxiliary information thereof are recorded into the database.

Secondly, database retrieval operation specifically comprises the following steps:

s1, performing service access on the pre-created image map information database, and introducing map browsing parameters as retrieval conditions, wherein the retrieval conditions comprise: the tile request level (Z), row number (X), column number (Y) calculate the corresponding range and attribute conditions for image file expansion (one or more of image accessory information defined when the image map information database is pre-created).

As described above, the accessory information category of the image raster data includes one or more of a file path, affine transformation information, spatial information, coordinate system information, a satellite type, a sensor type, a product type, shooting time, production department information, and an arrangement manner; thus, service access is made with parameters that pass into one or more of the categories described above.

And S2, retrieving a target image data list from the image map information database according to the transmitted retrieval conditions.

Specifically, for example, the parameters introduced in the request for service access have spatial information, and the corresponding tile range is calculated according to the level (Z), the row number (X) and the column number (Y) of the request; and integrating other expansion auxiliary information, and searching a target Image data List Image _ List meeting the requirement from a system space database.

Index information is established in space and other accessory information of data, corresponding image data meeting requirements are retrieved from a database according to a retrieval condition brought in real time and a browsing tile area, and the performance bottleneck brought by data quantity improvement is reduced while the retrieval purpose is achieved.

And S3, analyzing the target image data list, and combining the target image data list and the personalized browsing parameters to perform tile data coding to obtain a coding result.

Specifically, the target image data list and the personalized browsing parameters include a tile format, a transparent color, a brightness, RGB color values, and the like, the file number and the personalized browsing parameters are formatted into character strings respectively, and then the formatted character strings are encoded, specifically, the formatted character strings may be encoded in an encrypted or non-encrypted manner.

The encoding mode may adopt a conventional encoding mode, for example, file numbers in the data list are sequentially formatted into a character string a, personalized browsing parameters are formatted into a character string B, and a unique code TCID — MD5(Z + X + Y + a + B) is calculated. It should be noted that the MD5 encoding method is only an example, and is not taken as a basis for limiting the protection scope of the present invention, since other encoding methods in the prior art can implement the technical solution of the present invention.

S4, acquiring the corresponding tile from the specific storage area according to the encoding result, if the acquisition is successful, directly returning the acquired tile to the client, otherwise, executing S5-S6; wherein the specific storage area is different from the storage address of the image map information database.

As described above, if the area is actually not browsed for the first time, that is, the user has browsed the area before, or for the areas browsed by other users, the tile information may be directly obtained in the cache area according to the unique encoding result and returned;

if the area is actually browsed for the first time, S5-S6 are executed.

And S5, calling a tile generation module according to the target image data list and the analysis result thereof to generate a corresponding tile.

The specific steps of invoking the tile generation module to generate the corresponding tile are shown in fig. 2, and include the following steps:

s500, analyzing tile parameters and parameters of the target image data list, and initializing a tile memory structure;

s501, acquiring the number of image files in the target image data list, traversing the list to acquire an image file i, wherein i is initialized to 0, if i is less than the number of the files, the traversal is not finished, and S502 is executed, otherwise, the traversal is finished, and S507 is executed;

s502, if the coordinate system of the image file i is not consistent with the tile coordinate system, executing S503-S505 (for converting the coordinate system), otherwise executing S506;

Because the step S506/507 adopts a mechanism of filling and returning, redundant pictures do not need to be generated after filling, the number of files opened in the tile generation process is reduced, system IO access is reduced, and the system performance is not limited by data volume under the condition of ensuring correct display vision. The retrieval condition-based personalized tile map returning mechanism can not only guarantee the requirements of users for browsing tiles in a personalized manner, but also meet the retrieval requirements of the users.

The specific storage area is a cache, a database or a memory hash table, taking the cache as an example, the steps S5-S6 are to generate tiles to return to the client, and simultaneously write the generated tiles and the corresponding encoding results into the cache, so as to construct cache key values for newly generated tile files, so that when the area is browsed next time, tile information can be directly obtained in the cache area according to the unique encoding results, and the efficiency of matching the tiles in the cache area through the cache key values is far higher than that of retrieving image information in the database through expanding raster tile map parameters, so that constructing the cache key values can reduce the system response time under the condition of meeting the retrieval requirements.

In one embodiment of the present invention, a tile map system is provided, the tile map system comprising a server, a database, and a tile generation module, the server for executing the following instructions:

otherwise, executing S506;

The tile map system embodiment provided by the above embodiment and the WMTS dynamic tile map making method based on search conditions provided by the above embodiment belong to the same concept, and a specific implementation process thereof is detailed in the method embodiment, that is, all features in the WMTS dynamic tile map making method based on search conditions may be introduced into the tile map system embodiment by way of reference.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.

Claims

1. A WMTS dynamic tile map making method based on retrieval conditions is executed by a tile map system, the tile map system comprises a database and a tile generation module, and the WMTS dynamic tile map making method is characterized by comprising the following steps:

2. The WMTS dynamic tile mapping method of claim 1, wherein said step of invoking a tile generation module to generate a corresponding tile comprises:

s502, if the coordinate system of the image file i is inconsistent with the tile coordinate system, executing S503-S505, otherwise executing S506;

s504, the first clipping file is placed into a memory, and memory file re-projection transformation is carried out on the first clipping file, so that a memory file coordinate system is consistent with a tile coordinate system;

3. The WMTS dynamic tile mapping method of claim 1, wherein S1 is preceded by pre-creating a video map information database by:

4. The WMTS dynamic tile mapping method according to claim 3, wherein the step S002 of entering the image file into the database further comprises:

5. The method as claimed in claim 1, wherein the customized browsing parameters include one or more of tile format, transparent color, brightness, RGB color values, the target image data list and the customized browsing parameters are formatted into character strings, and the formatted character strings are encoded.

6. The WMTS dynamic tile mapping method of claim 5, wherein said formatted string is encoded in an encrypted or unencrypted manner.

7. The WMTS dynamic tile mapping method of claim 1, wherein step S2 further comprises:

8. The WMTS dynamic tile mapping method according to claim 1, wherein the specific storage area is a cache, a database or an in-memory hash table.

9. A tile map system, comprising a server, a database, and a tile generation module, the server configured to execute instructions to:

10. The tile map system of claim 9, wherein the server, upon invoking the tile generation module, executes the following instructions: