Image tile-based iOS end background map display method and system, and medium

Abstract

The invention discloses an iOS end background map display method and system based on picture tiles and a medium. The method comprises the steps that the map tiles of a to-be-displayed map area in a picture format are acquired; on the basis of longitude linear mapping and latitude Mercator projection, geographic tile coordinates of any point in the map tiles are converted into screen pixel coordinates in a display screen; and carrying out smooth movement on the screen pixel coordinate of any point in a display screen based on a smooth movement algorithm. Based on the data processing flow, a background map display scheme without depending on a GPU interface provided by the invention realizes that a program can be continuously rendered when a background screen is locked, so that map projection is not interrupted.

Description

Technical Field

[0001] This invention relates to the field of background map display technology on iOS devices, and in particular to a method, system, and medium for displaying background maps on iOS devices based on image tiles. Background Technology

[0002] In iOS, due to limitations in system resource allocation strategies, background applications cannot call the GPU (Graphics Processing Unit) interface for graphics rendering. This causes applications that rely on GPU acceleration, such as vector maps and video playback, to fail to display content correctly when in the background or in a locked screen state. Consequently, in the field of interconnected screen mirroring, maps cannot be mirrored in this situation. Existing solutions mostly rely on system-level permissions or GPU passthrough technology, which have high barriers to entry and high development costs.

[0003] Therefore, this invention addresses the limitations of background graphics rendering in iOS systems by providing a background map display solution that does not rely on the GPU interface, enabling the program to continue rendering in the background or when the system screen is locked, thus achieving uninterrupted map projection. Summary of the Invention

[0004] This invention provides a method, system, and medium for background map display on iOS based on image tiles. It eliminates the need to rely on the GPU interface for background map display, allowing the program to continue rendering even when the screen is locked in the background, thus achieving uninterrupted map projection.

[0005] Firstly, a method for displaying a background map on an iOS device based on image tiles is provided, including: Obtain map tiles of the map area to be displayed in image format; Based on longitude linear mapping and latitude Mercator projection, the geographic tile coordinates of any point in the map tile are converted into screen pixel coordinates on the display screen. The screen pixel coordinates of any point are smoothly moved across the display screen based on the smooth movement algorithm.

[0006] In some embodiments, obtaining map tiles of the map area to be displayed in image format includes: Set up a tile data server, and dynamically generate map tiles in image format for the map area to be displayed by setting the tile scaling level and the range of geographic tile coordinates.

[0007] In some embodiments, the step of converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitudinal Mercator projection includes: Calculate the number of tiles per side length of the map area to be displayed based on the tile scaling level; Based on the number of tiles with the specified side length, perform a longitude linear mapping of the geographic tile coordinates of any point in the map tiles; Based on the number of side-length tiles, perform a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tiles; Based on the results of the longitude linear mapping and the latitude Mercator projection, the screen pixel coordinates of the geographic tile coordinates of any point in the map tile are obtained on the display screen.

[0008] In some embodiments, the method for linearly mapping the geographic tile coordinates of any point in the map tiles according to the number of side-length tiles is shown in the following formula: tileX = (lon + 180.0) / 360.0 n; The method for performing a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tile based on the side length and number of tiles is shown in the following formula: tileY = (1.0 - log(tan(lat π / 180.0) + 1.0 / cos(lat) π / 180.0)) / π) / 2.0 n; In the formula, tileX is the result of longitude linear mapping; tileY is the result of latitude Mercator projection; (lon, lat) is the geographic latitude and longitude coordinates of any point in the map tile; and n is the number of tiles with side length.

[0009] In some embodiments, the method for obtaining the screen pixel coordinates of any point in the map tile on the display screen based on the longitude linear mapping result and the latitude Mercator projection result is shown in the following formula: x=tileX TILE SIZE y=tileY TILE SIZE ; In the formula, (x, y) represents the geographic tile coordinates of any point in the map tile as its screen pixel coordinates on the display screen; TILE SIZE `tileX` represents the tile size; `tileY` represents the result of the longitude linear mapping; `tileY` represents the result of the latitude Mercator projection.

[0010] In some embodiments, the smooth movement algorithm for smoothly moving the screen pixel coordinates of any point on the display screen includes: Calculate the coordinate difference of any point's screen pixel coordinates as it moves across the display screen; Set the map displacement animation to N frames; If the result of dividing the coordinate difference by N frames is within a preset range, then the movement of any point is smooth.

[0011] In some embodiments, after converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitudinal Mercator projection, the process includes: Set the visible display area of ​​the display screen; When map movement is detected, if the screen pixel coordinates of any image tile are not within the visible display area, the image tile that is not within the range will be removed from the display view and set in the first-level cache.

[0012] Secondly, an iOS background map display system based on image tiles is provided, including: The map tile acquisition module is used to acquire map tiles of the map area to be displayed in image format; A coordinate transformation module, communicatively connected to the map tile module, is used to convert the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitudinal Mercator projection; and... The smooth movement module is communicatively connected to the coordinate transformation module and is used to smoothly move the screen pixel coordinates of any point on the display screen based on the smooth movement algorithm.

[0013] In some embodiments, a cache module communicatively connected to the coordinate transformation module is also included, which is used to set the visible display area of ​​the display screen; when map movement is detected, if the screen pixel coordinates corresponding to any image tile are not within the visible display area, the image tile that is not within the range is removed from the display view and simultaneously set in the first-level cache.

[0014] Thirdly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the iOS background map display method based on image tiles as described above.

[0015] Compared with existing technologies, the advantages of this invention are as follows: It acquires map tiles of the map area to be displayed in image format; based on longitude linear mapping and latitude Mercator projection, it converts the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen; and based on a smooth movement algorithm, it smoothly moves the screen pixel coordinates of any point on the display screen. Based on the above data processing flow, this invention provides a background map display solution that does not rely on a GPU interface, enabling the program to continue rendering when the screen is locked in the background, thus achieving uninterrupted map projection. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating an iOS client background map display method based on image tiles according to the present invention. Figure 2 This is a schematic diagram of the structure of an iOS client background map display system based on image tiles according to the present invention. Detailed Implementation

[0017] Referring now to specific embodiments of the invention, examples of which are illustrated in the accompanying drawings. Although the invention will be described in conjunction with specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. Rather, it is intended to cover variations, modifications, and equivalents included within the spirit and scope of the invention as defined by the appended claims. It should be noted that the method steps described herein can be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of both.

[0018] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Note: The examples described below are merely specific examples and are not intended to limit the embodiments of the present invention to the specific steps, values, conditions, data, order, etc. Those skilled in the art can utilize the concept of the present invention to construct more embodiments not mentioned herein by reading this specification.

[0020] Please see Figure 1 This invention provides a flowchart illustrating a method for displaying a background map on an iOS device based on image tiles. The method includes: Step S100: Obtain map tiles of the map area to be displayed in image format, including: Set up a tile data server, and dynamically generate map tiles in image format for the map area to be displayed by setting the tile scaling level and the range of geographic tile coordinates.

[0021] Specifically, in this embodiment, a tile data server is set up. This server is specifically designed to provide small data "tiles" to the client on demand, using a fixed grid slicing method. Based on the tile zoom level, the range of x and y geographic tile coordinates, and other request parameters such as text language and map style, image tiles for the map area to be displayed are dynamically pre-generated. These image tiles are then transmitted to the iOS mobile device via the tile data server interface. The iOS mobile device can directly obtain the map tiles in image format through this interface, and then combine it with a self-developed lightweight engine to achieve efficient loading and rendering of the tiles. The specific loading and rendering process is described below.

[0022] Therefore, in navigation scenarios, when the user switches to the background, the map can still be displayed as an image. Because it is an image format, it does not rely on GPU rendering, so the image can be displayed naturally.

[0023] Step S200: Based on longitude linear mapping and latitude Mercator projection, the geographic tile coordinates of any point in the map tile are converted into screen pixel coordinates on the display screen.

[0024] Specifically, by encapsulating the conversion interface between the mobile view coordinate system and the geographic coordinate system, the accurate positioning of map elements is ensured at different zoom levels and rotation angles. When a user rotates their phone to view the map in a moving scene, the route and points of interest are always displayed in the correct direction and scale, avoiding positioning deviations caused by changes in viewing angle. This involves mapping geographic coordinates to a planar coordinate system using Mercator projection, calculating tile coordinates based on the zoom level and tile size, and then converting the tile coordinates to screen pixel coordinates. The specific steps include: S210, the side length and number of tiles n of the map area to be displayed are calculated based on the tile scaling level as follows: n = 2^zoom, where zoom is the map zoom level; S220, the method for linearly mapping the geographic tile coordinates of any point in the map tiles according to the number of side-length tiles is shown in the following formula: tileX = (lon + 180.0) / 360.0 n; S230, the method for performing latitudinal Mercator projection on the geographic tile coordinates of any point in the map tile according to the number of side-length tiles is as follows: tileY = (1.0 - log(tan(lat π / 180.0) + 1.0 / cos(lat) π / 180.0)) / π) / 2.0 n; In the formula, tileX is the result of longitude linear mapping; tileY is the result of latitude Mercator projection; (lon, lat) is the geographic latitude and longitude coordinates of any point in the map tile; and n is the number of tiles with side length.

[0025] S240, the method for obtaining the screen pixel coordinates of any point in the map tile in the display screen based on the longitude linear mapping result and the latitude Mercator projection result is as follows: x=tileX TILE SIZE y=tileY TILE SIZE ; In the formula, (x, y) represents the geographic tile coordinates of any point in the map tile as its screen pixel coordinates on the display screen; TILE SIZE `tileX` represents the tile size; `tileY` represents the result of the longitude linear mapping; `tileY` represents the result of the latitude Mercator projection.

[0026] Step S300, based on a smooth movement algorithm, smoothly move the screen pixel coordinates of any point on the display screen, including: Calculate the coordinate difference of any point's screen pixel coordinates as it moves across the display screen; Set the map displacement animation to N frames; If the result of dividing the coordinate difference by N frames is within a preset range, then the movement of any point is smooth.

[0027] Specifically, in this embodiment, for example, if the center point of the map needs to move from point A(x1,y1) to point B(x2,y2), the latitude and longitude difference is first calculated to obtain Δ = (x2-x1,y2-y1). The callback time interval of the moving point is known to be t. Assuming that we set the displacement animation to N frames, the displacement time interval between two frames is Δt = t / N, that is, the displacement is divided into N times, and the movement amount of each time is ((x2-x1) / N, (y2-y1) / N). When N is greater than a certain value, such as 20, the displacement appears to be a continuous animation. Therefore, CPU-based time-sharing frame animation is realized.

[0028] Therefore, even when the map is running in the background, the map content can still move smoothly and continuously during navigation, avoiding stuttering or frame skipping.

[0029] Step S200, after converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitude Mercator projection, includes: Set the visible display area of ​​the display screen; When map movement is detected, if the screen pixel coordinates of any image tile are not within the visible display area, the image tile that is not within the range will be removed from the display view and set in the first-level cache.

[0030] Specifically, in this embodiment, the present invention can monitor the visible area of ​​the screen in real time, download and release tiles on demand in a grid pattern, and optimize memory usage by combining a first-level cache (high-frequency area) and a second-level cache (low-frequency area). During map scrolling, when the user quickly pans the map, only the tiles of the currently visible area are loaded, reducing memory consumption.

[0031] 1. Visible Area Calculation: The visible area of ​​the current screen can be obtained directly through the API. Based on the coordinate system transformation algorithm in the previous step, the map area to be displayed can be calculated. That is, tiles within the area that have not been loaded will be downloaded from the network, while those that have been downloaded will continue to be displayed without additional processing. Tiles outside the visible area will be removed from the view. In other words, only the tiles that must be displayed will be loaded to reduce memory usage. 2. Level 1 Cache: Also known as a high-speed cache, it is stored in memory. In the above steps, tiles removed from the view are first placed in the level 1 cache. This allows tile data to be quickly retrieved from memory when the map rotates or moves, avoiding the waste of bandwidth from loading directly from the network and the resource consumption of frequent flash memory reads. The level 1 cache is set to a certain size, such as 50MB, to prevent program malfunctions due to excessive memory consumption. 3. Secondary cache: also known as low-speed cache, is stored in flash memory. It is mainly used to reduce network traffic consumption when the map is moved repeatedly. It is usually set with a large space, such as 500MB. Users can clear it as needed. See also Figure 2 As shown, this embodiment of the invention also provides an iOS background map display system based on image tiles, including: The map tile acquisition module is used to acquire map tiles of the map area to be displayed in image format; A coordinate transformation module, communicatively connected to the map tile module, is used to convert the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitudinal Mercator projection; and... The smooth movement module is communicatively connected to the coordinate transformation module and is used to smoothly move the screen pixel coordinates of any point on the display screen based on the smooth movement algorithm.

[0032] The map tile acquisition module includes: Set up a tile data server, and dynamically generate map tiles in image format for the map area to be displayed by setting the tile scaling level and the range of geographic tile coordinates.

[0033] The coordinate transformation module includes: Calculate the number of tiles per side length of the map area to be displayed based on the tile scaling level; Based on the number of tiles with the specified side length, perform a longitude linear mapping of the geographic tile coordinates of any point in the map tiles; Based on the number of side-length tiles, perform a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tiles; Based on the results of the longitude linear mapping and the latitude Mercator projection, the screen pixel coordinates of the geographic tile coordinates of any point in the map tile are obtained on the display screen.

[0034] In some embodiments, the method for linearly mapping the geographic tile coordinates of any point in the map tiles according to the number of side-length tiles is shown in the following formula: tileX = (lon + 180.0) / 360.0 n; The method for performing a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tile based on the side length and number of tiles is shown in the following formula: tileY = (1.0 - log(tan(lat π / 180.0) + 1.0 / cos(lat) π / 180.0)) / π) / 2.0 n; In the formula, tileX is the result of longitude linear mapping; tileY is the result of latitude Mercator projection; (lon, lat) is the geographic latitude and longitude coordinates of any point in the map tile; and n is the number of tiles with side length.

[0035] In some embodiments, the method for obtaining the screen pixel coordinates of any point in the map tile on the display screen based on the longitude linear mapping result and the latitude Mercator projection result is shown in the following formula: x=tileX TILE SIZE y=tileY TILE SIZE ; In the formula, (x, y) represents the geographic tile coordinates of any point in the map tile as its screen pixel coordinates on the display screen; TILE SIZE `tileX` represents the tile size; `tileY` represents the result of the longitude linear mapping; `tileY` represents the result of the latitude Mercator projection.

[0036] In some embodiments, the smooth movement algorithm for smoothly moving the screen pixel coordinates of any point on the display screen includes: Calculate the coordinate difference of any point's screen pixel coordinates as it moves across the display screen; Set the map displacement animation to N frames; If the result of dividing the coordinate difference by N frames is within a preset range, then the movement of any point is smooth.

[0037] The system of the present invention also includes a cache module that is communicatively connected to the coordinate transformation module, used to set the visible display area of ​​the display screen; when map movement is detected, if the screen pixel coordinates corresponding to any image tile are not within the visible display area, the image tile that is not within the range is removed from the display view and simultaneously set in the first-level cache.

[0038] In summary, the main advantages of this invention are: acquiring map tiles of the map area to be displayed in image format; converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitude Mercator projection; and smoothly moving the screen pixel coordinates of any point on the display screen based on a smooth movement algorithm. Based on the above data processing flow, this invention provides a background map display solution that does not rely on a GPU interface, enabling the program to continue rendering when the screen is locked in the background, thus achieving uninterrupted map projection. Therefore, when navigating, the mobile app can be switched to the background or the phone screen can be locked, and the map can be rendered and displayed on the vehicle's infotainment system through interconnection technology, thereby achieving the function of continuing map projection even when the screen is locked.

[0039] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements all or part of the method steps of the above method.

[0040] The present invention can implement all or part of the processes in the above methods, or it can be accomplished by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content contained in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0041] Based on the same inventive concept, embodiments of this application also provide an electronic device, including a memory and a processor. The memory stores a computer program that runs on the processor. When the processor executes the computer program, it implements all or part of the method steps described above.

[0042] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the computer device, connecting all parts of the computer device through various interfaces and lines.

[0043] Memory can be used to store computer programs and / or modules. The processor performs various functions of the computer device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can primarily include a program storage area and a data storage area. The program storage area can store the operating system and at least one application program required for a function (e.g., sound playback, image playback, etc.); the data storage area can store data created based on the use of the mobile phone (e.g., audio data, video data, etc.). Furthermore, memory can include high-speed random access memory, and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMedia Cards (SMC), Secure Digital (SD) cards, Flash Cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0044] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, servers, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0045] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), servers, and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0046] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0047] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0048] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for displaying a background map on an iOS device based on image tiles, characterized in that, include: Obtain map tiles of the map area to be displayed in image format; Based on longitude linear mapping and latitude Mercator projection, the geographic tile coordinates of any point in the map tile are converted into screen pixel coordinates on the display screen. The screen pixel coordinates of any point are smoothly moved across the display screen based on the smooth movement algorithm.

2. The iOS background map display method based on image tiles as described in claim 1, characterized in that, The process of obtaining map tiles of the map area to be displayed in image format includes: Set up a tile data server, and dynamically generate map tiles in image format for the map area to be displayed by setting the tile scaling level and the range of geographic tile coordinates.

3. The iOS background map display method based on image tiles as described in claim 1, characterized in that, The method of converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and dimensional Mercator projection includes: Calculate the number of tiles per side length of the map area to be displayed based on the tile scaling level; Based on the number of tiles with the specified side length, perform a longitude linear mapping of the geographic tile coordinates of any point in the map tiles; Based on the number of side-length tiles, perform a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tiles; Based on the results of the longitude linear mapping and the latitude Mercator projection, the screen pixel coordinates of the geographic tile coordinates of any point in the map tile are obtained on the display screen.

4. The iOS background map display method based on image tiles as described in claim 3, characterized in that, The method for linearly mapping the geographic tile coordinates of any point in the map tiles according to the number of tiles with the specified side length is shown in the following formula: tileX = (lon + 180.0) / 360.0 n ; The method for performing a latitudinal Mercator projection on the geographic tile coordinates of any point in the map tile based on the side length and number of tiles is shown in the following formula: tileY = (1.0 - log(tan(lat π / 180.0) + 1.0 / cos(lat π / 180.0)) / π) / 2.0 n; In the formula, tileX is the result of longitude linear mapping; tileY is the result of latitude Mercator projection; (lon, lat) is the geographic latitude and longitude coordinates of any point in the map tile; and n is the number of tiles with side length.

5. The iOS background map display method based on image tiles as described in claim 3, characterized in that, The method for obtaining the screen pixel coordinates of any point in the map tile in the display screen based on the longitude linear mapping result and the latitude Mercator projection result is shown in the following formula: x=tileX TILE SIZE y=tileY TILE SIZE ; In the formula, (x, y) represents the geographic tile coordinates of any point in the map tile as its screen pixel coordinates on the display screen; TILE SIZE `tileX` represents the tile size; `tileY` represents the result of the longitude linear mapping; `tileY` represents the result of the latitude Mercator projection.

6. The iOS background map display method based on image tiles as described in claim 1, characterized in that, The smooth movement algorithm smoothly moves the screen pixel coordinates of any point on the display screen, including: Calculate the coordinate difference of any point's screen pixel coordinates as it moves across the display screen; Set the map displacement animation to N frames; If the result of dividing the coordinate difference by N frames is within a preset range, then the movement of any point is smooth.

7. The iOS background map display method based on image tiles as described in claim 1, characterized in that, After converting the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitude Mercator projection, the process includes: Set the visible display area of ​​the display screen; When map movement is detected, if the screen pixel coordinates of any image tile are not within the visible display area, the image tile that is not within the range will be removed from the display view and set in the first-level cache.

8. A background map display system for iOS based on image tiles, characterized in that, include: The map tile acquisition module is used to acquire map tiles of the map area to be displayed in image format; A coordinate transformation module, communicatively connected to the map tile module, is used to convert the geographic tile coordinates of any point in the map tiles into screen pixel coordinates on the display screen based on longitude linear mapping and latitudinal Mercator projection; and... The smooth movement module is communicatively connected to the coordinate transformation module and is used to smoothly move the screen pixel coordinates of any point on the display screen based on the smooth movement algorithm.

9. The iOS background map display system based on image tiles as described in claim 8, characterized in that, It also includes a cache module that is communicatively connected to the coordinate transformation module, used to set the visible display area of ​​the display screen; when map movement is detected, if the screen pixel coordinates corresponding to any image tile are not within the visible display area, the image tile that is not within the range is removed from the display view and simultaneously set in the first-level cache.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the iOS background map display method based on image tiles as described in any one of claims 1 to 7.

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