Multi-scale island remote sensing image mosaic mapping method, device and equipment and medium

Abstract

This application provides a multi-scale island and reef remote sensing image mosaic mapping method, which can be applied to the fields of geographic information science and remote sensing big data processing technology. The method includes: acquiring island and reef image files corresponding to each island and reef in a target area; the island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to a buffer distance, with the geometric center of the island and reef as the reference; based on the spatial display scale corresponding to the buffer distance, stitching together the island and reef image files of all islands and reefs in the target area to generate an image mosaic map; generating a vector index map that corresponds one-to-one with the geometric position of the image mosaic map, the vector index map containing island and reef identification information of the corresponding geometric position of the island and reef; and superimposing the vector index map onto a predetermined area of ​​the image mosaic map to generate a standardized island and reef thematic map of the target area. This application also provides a multi-scale island and reef remote sensing image mosaic mapping device, equipment, and storage medium.

Description

Technical Field

[0001] This application relates to the fields of geographic information science and remote sensing big data processing, specifically to a multi-scale island and reef remote sensing image mosaic mapping method, apparatus, equipment, and medium. Background Technology

[0002] Islands and reefs are key areas for safeguarding maritime rights and interests and monitoring ecosystems. Regularly acquiring high-resolution remote sensing images of all islands and reefs and creating thematic maps is fundamental work in the field of marine remote sensing.

[0003] However, current remote sensing data acquisition mainly relies on fixed "map sheets" or "scenes" distribution systems, with single-scene images covering a large area, such as 100km × 100km. In contrast, islands and reefs are generally small, with most sandbars less than 0.1km². Traditional methods require downloading entire scene images to obtain only a tiny fraction of the island and reef area, leading to massive data redundancy and a severe waste of storage and processing resources. Furthermore, the consistently high cloud cover in tropical maritime climate zones poses a significant challenge to optical remote sensing imaging. Cloud detection algorithms for single-scene images easily confuse bright sandbars with clouds, and single-temporal images often fail to reflect the true shape of islands and reefs, even leading to misjudgments due to high tide. Existing simple composite methods based on multi-temporal data often suffer from uneven tonal distribution and geometric misalignment due to improper time window selection.

[0004] In addition, islands and reefs have significant multi-scale characteristics. When dealing with mapping tasks of such discontinuously distributed targets, existing geographic information system software uses a fixed map frame, which makes it difficult to identify small-scale islands and reefs on the map, and large-scale islands and reefs lack detail. The quality of the map depends on manual adjustment one by one, which is inefficient and makes it difficult to guarantee standardization. Summary of the Invention

[0005] In view of the above problems, this application provides a method, apparatus, equipment and medium for multi-scale island and reef remote sensing image mosaic mapping.

[0006] According to a first aspect of this application, a multi-scale island and reef remote sensing image mosaic mapping method is provided. The method includes: acquiring island and reef image files corresponding to each island and reef in a target area, wherein the island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to a buffer distance with the geometric center of the island and reef as the reference; stitching together the island and reef image files of all islands and reefs in the target area based on the spatial display scale corresponding to the buffer distance to generate an image mosaic map; generating a vector index map that corresponds one-to-one with the geometric position of the image mosaic map, wherein the vector index map contains island and reef identification information of the geometric position of the corresponding island and reef; and superimposing the vector index map on a predetermined area of ​​the image mosaic map to generate a standardized island and reef thematic map of the target area.

[0007] According to an embodiment of this application, the acquisition of island and reef image files includes: obtaining the center point coordinates and preset buffer radius of each island and reef in the target area based on an island and reef geographic information database; constructing a rectangular search range based on the island and reef center point coordinates and buffer radius, performing spatiotemporal retrieval on an optical remote sensing satellite image set to obtain a candidate image set for the island and reef; performing pixel-level cloud removal processing on each image in the candidate image set to synthesize a cloud-free image corresponding to the island and reef; and downloading the synthesized cloud-free image in segments to the local machine to form the island and reef image file.

[0008] According to an embodiment of this application, the step of performing pixel-level cloud removal processing on each image in the candidate image set to synthesize a cloud-free image corresponding to the island and reef includes: identifying cloud pixels pixel by pixel in each image in the candidate image set; selecting multiple target images in the candidate image set whose cloud pixel ratio is lower than a preset ratio based on the proportion of cloud pixels; and synthesizing a cloud-free image of the island and reef based on the multiple target images.

[0009] According to an embodiment of this application, the step of identifying cloud pixels pixel by pixel in each image of the candidate image set includes: performing a cloud score on each pixel of each image of the candidate image set; and identifying cloud pixels in each image based on the cloud score.

[0010] According to an embodiment of this application, the step of synthesizing a cloudless image of the island and reef based on the plurality of target images includes: performing median synthesis on the plurality of target images to obtain a median image; calculating the effective pixel coverage ratio in the median image; if the effective pixel coverage ratio reaches a preset threshold, then incrementally introducing new target images for mosaicking until the effective pixel coverage ratio reaches a preset target.

[0011] According to an embodiment of this application, the step of stitching together all island and reef image files within the target area to generate an image mosaic based on the spatial display scale corresponding to the buffer distance includes: grouping island and reef image files with the same buffer distance into the same buffer group, each buffer group corresponding to a spatial display scale; stitching together the island and reef image files to generate an image mosaic based on the spatial display scale corresponding to each buffer group; wherein, the buffer distance is positively correlated with the size of the island and reef, and the spatial display scale is negatively correlated with the size of the buffer distance.

[0012] According to an embodiment of this application, the step of overlaying the vector index map onto a predetermined area of ​​the image mosaic to generate a standardized island and reef thematic map of the target area includes: overlaying vector boundaries onto the island and reef outlines in the island and reef image file based on the vector boundary data of the islands and reefs; overlaying the reduced vector index map onto a preset area of ​​the image mosaic to form an overlaid image; and adding a north arrow, scale bar, timestamp, and corresponding descriptive text for the islands and reefs to the overlaid image to generate a standardized island and reef thematic map.

[0013] According to a second aspect of this application, a multi-scale island and reef remote sensing image mosaic mapping device is provided. The device includes: an image acquisition module for acquiring island and reef image files corresponding to each island and reef in a target area, wherein the island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to a buffer distance with the geometric center of the island and reef as the reference; an image mosaic module for stitching together the island and reef image files of all islands and reefs in the target area based on the spatial display scale corresponding to the buffer distance to generate an image mosaic map; an index generation module for generating a vector index map that corresponds one-to-one with the geometric position of the image mosaic map, wherein the vector index map contains island and reef identification information of the corresponding geometric position of the island and reef; and an image overlay module for overlaying the vector index map onto a predetermined area of ​​the image mosaic map to generate a standardized island and reef thematic map of the target area.

[0014] A third aspect of this application provides an electronic device comprising: one or more processors; and a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method described above.

[0015] A fourth aspect of this application also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the above-described method.

[0016] The multi-scale island and reef remote sensing image mosaic mapping method provided in this application has at least the following beneficial effects:

[0017] (1) An adaptive buffer clipping strategy centered on islands and reefs is adopted to obtain only the effective area of ​​islands and reefs, thus avoiding data redundancy caused by downloading the entire scene;

[0018] (2) Construct a grouping mechanism based on buffer distance and a sorting strategy based on area to dynamically adjust the visual proportion of islands and reefs at different scales;

[0019] (3) The image mosaic map and vector index map are generated synchronously through the location table to achieve geometric correspondence between the two maps and avoid manual adjustment of the layout;

[0020] (4) This method can automatically complete the entire process from image acquisition to map output, generating standardized results containing cartographic elements and summary files. Attached Figure Description

[0021] The above-mentioned contents, other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0022] Figure 1 A flowchart illustrating a multi-scale island and reef remote sensing image mosaicking method according to an embodiment of this application is shown schematically.

[0023] Figure 2 The illustration shows the implementation steps of the multi-scale island and reef remote sensing image mosaic mapping method according to an embodiment of this application;

[0024] Figure 3 This illustration schematically shows a process diagram for obtaining island and reef image files according to an embodiment of this application;

[0025] Figure 4 This schematically illustrates a structural block diagram of a multi-scale island and reef remote sensing image mosaic mapping apparatus according to an embodiment of this application; and

[0026] Figure 5 A block diagram schematically illustrates an electronic device suitable for implementing a multi-scale island and reef remote sensing image mosaic mapping method according to an embodiment of this application. Detailed Implementation

[0027] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0029] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0030] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0031] Figure 1 and 2 The flowchart and implementation steps of the multi-scale island and reef remote sensing image mosaic mapping method according to an embodiment of this application are illustrated schematically.

[0032] like Figure 1 As shown, the multi-scale island and reef remote sensing image mosaic mapping method of this embodiment includes operations S110 to S140, and the transaction processing method can be executed sequentially.

[0033] In operation S110, the image files of each island and reef in the target area are obtained. The image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to the buffer distance with the geometric center of the island and reef as the reference.

[0034] Figure 3 The illustration shows a schematic diagram of the process for obtaining island and reef image files according to an embodiment of this application.

[0035] like Figure 3 As shown, obtaining the island and reef image files corresponding to each island and reef in the target area includes operations S111~S114.

[0036] In operation S111, the center point coordinates of each island and reef in the target area and the preset buffer radius are obtained based on the island and reef geographic information database.

[0037] In this embodiment, the center point coordinates and preset buffer radii of each island and reef in the target area are obtained based on an island and reef geographic information database. The island and reef geographic information database pre-stores the high-precision center coordinates, geometric shape IDs, and preset buffer radii based on the physical size of each island and reef. The buffer radius is positively correlated with the size of the island or reef; that is, larger islands and reefs have preset larger buffer radii, and smaller islands and reefs have preset smaller buffer radii.

[0038] In operation S112, a rectangular search range is constructed based on the coordinates of the island / reef center point and the buffer radius. Spatiotemporal retrieval is performed on the optical remote sensing satellite image set to obtain a candidate image set for the island / reef.

[0039] In this embodiment of the application, for any island or reef center point, its latitude and longitude are set as follows: Given a buffer radius of d, and considering the influence of latitude on the longitude scale, the latitude and longitude offset of the buffer zone is approximately:

[0040]

[0041] in, This is the longitude offset. This represents the latitude offset, from which the rectangular search range is obtained.

[0042] The system performs spatial and temporal filtering on optical remote sensing satellite image sets (such as the Sentinel-2 image set) to form a candidate image set.

[0043] In operation S113, each image in the candidate image set is processed at the pixel level to remove clouds, and a cloud-free image corresponding to the island and reef is synthesized.

[0044] In the embodiments of this application, S113 includes S1131 to S1133.

[0045] In operation S1131, cloud pixels are identified pixel by pixel for each image in the candidate image set.

[0046] In this embodiment, a cloud scoring model is used to score each pixel in each image of the candidate image set. A lower cloud score indicates a higher probability that the pixel is a cloud. Based on the cloud score, cloud pixels in each image are identified. For example, the system sets a cloud score threshold of 0.6, and pixels with cloud scores below this threshold are identified as cloud pixels.

[0047] In operation S1132, based on the proportion of cloud pixels, multiple target images in the candidate image set whose proportion of cloud pixels is lower than a preset proportion are selected.

[0048] The proportion of cloud pixels to the total area within the buffer is used as the cloud coverage percentage, and only images with a cloud coverage percentage less than or equal to a preset cloud coverage threshold are retained for compositing.

[0049] For any pixel Cloud mask is defined as:

[0050]

[0051] in, For Cloud Score Plus, This is a cloud pixel indicator function. In the buffer... The percentage of cloud cover within the area is:

[0052]

[0053] in For buffer, For pixel area. The system satisfies the cloud cover ratio requirement. The images were filtered. This is the cloud cover threshold.

[0054] In operation S1133, cloudless images of islands and reefs are synthesized based on multiple target images.

[0055] In this embodiment, multiple target images are composited using median values ​​to obtain a median image. The effective pixel coverage ratio in the median image is calculated. If the effective pixel coverage ratio reaches a preset threshold, new target images are incrementally introduced for mosaicking until the effective pixel coverage ratio reaches a preset target or the optimal coverage result is obtained.

[0056] The coverage of the composite image is:

[0057]

[0058] in This is the valid pixel indicator function. If If the result is satisfactory, a composite image will be output; otherwise, the image will be converted to a scene-by-scene incremental mosaic and the best coverage result will be obtained.

[0059] In operation S114, the composite cloudless image segments are downloaded to the local machine to form island and reef image files.

[0060] In this embodiment, the cloudless image of a single island / reef is divided into grids at a preset resolution (e.g., 10-meter resolution), dividing the image into multiple tiles, and each tile is downloaded to local storage. After downloading, the offset position of each tile in the final image is calculated according to its row and column index, and then stitched together to restore the image. The row offsets are arranged in reverse order from top to bottom, generating a complete image file corresponding to each island / reef.

[0061] Where the grid size is Single-block index is Its offset in the final stitched image is:

[0062]

[0063] in Let be the grid side length. Row index for image blocks For column indexes of image blocks, The pixel width of the image block. The pixel height for image blocks. This strategy avoids failures caused by exceeding single-scene limits and network fluctuations, and ensures stitching integrity through a verification mechanism.

[0064] During operation S120, based on the spatial display scale corresponding to the buffer distance, all island and reef image files within the target area are stitched together to generate an image mosaic.

[0065] Operation S120 includes operations S121 to S122.

[0066] In operation S121, island and reef image files with the same buffer distance are grouped into the same buffer group, and each buffer group corresponds to a spatial display scale.

[0067] In operation S122, image mosaics are generated by stitching together the image files of each island and reef according to the spatial display scale corresponding to each buffer group.

[0068] In this embodiment, the buffer distance is positively correlated with the size of the islands and reefs, while the spatial display scale is negatively correlated with the buffer distance. That is, the larger the buffer distance, the smaller the corresponding spatial display scale (the fewer images are displayed in each row, and the larger the display area occupied by a single image in the mosaic). Based on the spatial display scale corresponding to each buffer group, the sorted island and reef image files within the group are stitched together to generate an image mosaic.

[0069] For any buffer distance Its scale ratio is defined as:

[0070]

[0071] in, And sort the images within each buffer group in ascending order of area:

[0072]

[0073] in .

[0074] Before grouping the island and reef image files by buffer distance, each buffer group is further sorted in ascending order by the actual land area of ​​the islands and reefs to ensure layout stability. Simultaneously, the scale ratio is determined based on the ratio of the buffer distance to a preset baseline distance (e.g., 11km), and the number of images displayed per row is dynamically adjusted according to this scale ratio: a smaller scale ratio results in more images displayed per row, and a larger scale ratio results in fewer images displayed per row, allowing large-scale island and reef images to occupy a larger display area in the image mosaic.

[0075] For example, the number of cells per row in the baseline is:

[0076]

[0077] According to the buffer ratio Dynamically adjust the file size of the island and reef image files in each row of the image mosaic:

[0078]

[0079] in, This represents the number of rows per buffer when the buffer distance is d.

[0080] In operation S130, a vector index map is generated that corresponds one-to-one with the geometric position of the image mosaic. The vector index map contains the island and reef identification information of the corresponding geometric position of the island and reef.

[0081] The vector index map contains island and reef identification information indicating the geometric location of the corresponding islands and reefs. Specifically, a location table identical to that of the image mosaic is created, recording the coordinates, row number, and column number of each island / reef image in the final layout. Based on this location table, a solid-color background is drawn at the corresponding grid position, and the island / reef name and latitude / longitude annotations are overlaid on the solid-color background to form the vector index map.

[0082] It should be noted that, as Figure 2 As shown, the system is based on the buffer ratio When adjusting the size (or layout) of the island and reef image files in each row of the image mosaic, record the location table. This location table is used for both stitching and retrieving image rendering, thus enabling simultaneous rendering of the two images.

[0083] In operation S140, the vector index map is overlaid on a predetermined area of ​​the image mosaic to generate a standardized thematic map of islands and reefs for the target area.

[0084] In this embodiment, based on the vector boundary data of islands and reefs, vector boundaries are superimposed on the island and reef outlines in the island and reef image file to delineate the island and reef contours. The island and reef names and date ranges are then labeled in the upper left corner of the image, generating a labeled single-island and reef image. A scaled-down vector index map is then superimposed on a preset area (e.g., a pre-defined blank area) of the image mosaic to form a superimposed image. A north arrow, scale bar, timestamp, and corresponding island and reef descriptions are added to the superimposed image to generate a standardized island and reef thematic map.

[0085] Based on the multi-scale island and reef remote sensing image mosaicking method provided in this application, a pixel-level cloud mask and coverage-driven strategy are used to synthesize island and reef images from low-cloud-coverage images. This effectively suppresses cloud shadow interference while maintaining clarity, ensuring detailed representation of islands and reefs and overall image integrity. The method introduces a buffer construction and multi-level block download mechanism to address the problems of exceeding limits and high failure rates when downloading large-scale high-resolution images, achieving stable and controllable high-resolution output and maintaining spatial continuity through automatic mosaicking. Based on adaptive grouping and sorting of geometric area, this method ensures stable and orderly arrangement of images at the same scale in the mosaic image, avoiding retrieval chaos caused by random layout. Simultaneously, dynamic grid layout and simultaneous generation of two images ensure a one-to-one correspondence between the mosaic image and the retrieval image, significantly improving readability and rapid location efficiency. Furthermore, this method establishes a unified output standard, including boundary overlay, date annotation, mosaic master map, and metadata summary, making the results traceable and consistent, facilitating subsequent archiving, review, and application.

[0086] Figure 4 A schematic diagram of a multi-scale island and reef remote sensing image mosaic mapping apparatus according to an embodiment of this application is shown.

[0087] like Figure 4 As shown, the multi-scale island and reef remote sensing image mosaic mapping device 400 of this embodiment includes an image acquisition module 410, an image mosaic module 420, an index generation module 430, and an image overlay module 440.

[0088] The image acquisition module 410 is used to acquire island and reef image files corresponding to each island and reef in the target area. The island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to the buffer distance with the geometric center of the island and reef as the reference. In one embodiment, the image acquisition module 410 can be used to perform the operation S110 described above, which will not be repeated here.

[0089] The image mosaic module 420 is used to stitch together all island and reef image files within the target area based on the spatial display scale corresponding to the buffer distance, generating an image mosaic map. In one embodiment, the image mosaic module 420 can be used to perform the operation S120 described above, which will not be repeated here.

[0090] The index generation module 430 is used to generate a vector index map that corresponds one-to-one with the geometric positions of the image mosaic. The vector index map contains island and reef identification information corresponding to the geometric positions of the islands and reefs. In one embodiment, the index generation module 430 can be used to perform the operation S130 described above, which will not be repeated here.

[0091] The image overlay module 440 is used to overlay a vector index map onto a predetermined area of ​​an image mosaic map to generate a standardized island and reef thematic map of the target area. In one embodiment, the image overlay module 440 can be used to perform the operation S140 described above, which will not be repeated here.

[0092] According to embodiments of this application, any multiple modules among the image acquisition module 410, image mosaicking module 420, index generation module 430, and image overlay module 440 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least some of the functions of one or more of these modules can be combined with at least some of the functions of other modules and implemented in one module. According to embodiments of this application, at least one of the image acquisition module 410, image mosaicking module 420, index generation module 430, and image overlay module 440 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or any other reasonable means of integrating or packaging the circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the image acquisition module 410, image mosaicking module 420, index generation module 430, and image overlay module 440 may be implemented at least partially as a computer program module, which can perform corresponding functions when the computer program module is run.

[0093] Figure 5 A block diagram schematically illustrates an electronic device suitable for implementing a multi-scale island and reef remote sensing image mosaic mapping method according to an embodiment of this application.

[0094] like Figure 5 As shown, an electronic device 500 according to an embodiment of this application includes a processor 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage portion 508 into a random access memory (RAM) 503. The processor 501 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 501 may also include onboard memory for caching purposes. The processor 501 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this application.

[0095] RAM 503 stores various programs and data required for the operation of electronic device 500. Processor 501, ROM 502, and RAM 503 are interconnected via bus 504. Processor 501 executes various operations of the method flow according to embodiments of this application by executing programs in ROM 502 and / or RAM 503. It should be noted that the programs may also be stored in one or more memories other than ROM 502 and RAM 503. Processor 501 may also execute various operations of the method flow according to embodiments of this application by executing programs stored in said one or more memories.

[0096] According to embodiments of this application, the electronic device 500 may further include an input / output (I / O) interface 505, which is also connected to a bus 504. The electronic device 500 may also include one or more of the following components connected to the input / output (I / O) interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the input / output (I / O) interface 505 as needed. A removable medium 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 510 as needed so that computer programs read from it can be installed into the storage section 508 as needed.

[0097] This application also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of this application.

[0098] According to embodiments of this application, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this application, the computer-readable storage medium may include ROM 502 and / or RAM 503 and / or one or more memories other than ROM 502 and RAM 503 described above.

[0099] Embodiments of this application also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code enables the computer system to implement the multi-scale island and reef remote sensing image mosaicking method provided in the embodiments of this application.

[0100] When the computer program is executed by the processor 501, it performs the functions defined in the system / apparatus of this application embodiment. According to the embodiments of this application, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0101] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 509, and / or installed from a removable medium 511. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0102] In such an embodiment, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by processor 501, it performs the functions defined in the system of this application embodiment. According to embodiments of this application, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0103] According to embodiments of this application, program code for executing the computer programs provided in the embodiments of this application can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0104] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0105] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

[0106] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this application, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this application.

Claims

1. A method for mosaicking multi-scale remote sensing images of islands and reefs, characterized in that, The method includes: Acquire the island and reef image files corresponding to each island and reef in the target area. The island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and have been cropped according to the buffer distance with the geometric center of the island and reef as the reference. Based on the spatial display scale corresponding to the buffer distance, the image files of all islands and reefs within the target area are stitched together to generate an image mosaic map; Generate a vector index map that corresponds one-to-one with the geometric position of the image mosaic, wherein the vector index map contains island and reef identification information corresponding to the geometric position of the island and reef; The vector index map is overlaid on a predetermined area of ​​the image mosaic to generate a standardized island and reef thematic map of the target area.

2. The method according to claim 1, characterized in that, The acquisition of island and reef image files corresponding to each island and reef in the target area includes: The coordinates of the center points of each island and reef in the target area and the preset buffer radius are obtained based on the island and reef geographic information database. A rectangular search range is constructed based on the coordinates of the island's center point and the buffer radius. Spatiotemporal retrieval is performed on the optical remote sensing satellite image set to obtain the candidate image set of the island. Each image in the candidate image set is subjected to pixel-level cloud removal processing to synthesize a cloudless image corresponding to the island and reef. The composite cloudless image segments are downloaded to the local machine to form the island and reef image file.

3. The method according to claim 2, characterized in that, The step of performing pixel-level cloud removal processing on each image in the candidate image set to synthesize a cloud-free image corresponding to the island and reef includes: For each image in the candidate image set, cloud pixels are identified pixel by pixel; Based on the proportion of cloud pixels, select multiple target images in the candidate image set whose proportion of cloud pixels is lower than a preset ratio. Based on the multiple target images, a cloudless image of the island and reef is synthesized.

4. The method according to claim 3, characterized in that, The step of identifying cloud pixels pixel-by-pixel in each image of the candidate image set includes: A cloud score is performed on each pixel of each image in the candidate image set; Based on the cloud score, cloud pixels in each image are identified.

5. The method according to claim 3, characterized in that, The process of synthesizing a cloudless image of the island / reef based on the multiple target images includes: Median composite is performed on the multiple target images to obtain a median image; Calculate the effective pixel coverage ratio in the median image; If the effective pixel coverage ratio reaches a preset threshold, new target images are introduced scene by scene for mosaicking until the effective pixel coverage ratio reaches the preset target.

6. The method according to claim 1, characterized in that, The step of stitching together all island and reef image files within the target area based on the spatial display scale corresponding to the buffer distance to generate an image mosaic includes: Image files of islands and reefs with the same buffer distance are grouped into the same buffer group, and each buffer group corresponds to a spatial display scale. Based on the spatial display scale corresponding to each buffer group, the image files of each island and reef are stitched together to generate an image mosaic. The buffer distance is positively correlated with the size of the island / reef, while the spatial display scale is negatively correlated with the size of the buffer distance.

7. The method according to claim 1, characterized in that, The step of overlaying the vector index map onto a predetermined area of ​​the image mosaic to generate a standardized island and reef thematic map of the target area includes: Based on the vector boundary data of the islands and reefs, the vector boundaries are superimposed on the island and reef outlines in the island and reef image files. The reduced vector index map is superimposed on a preset area of ​​the image mosaic to form a superimposed image; A compass rose, scale bar, timestamp, and corresponding descriptive text for the islands and reefs are added to the overlaid image to generate a standardized thematic map of the islands and reefs.

8. A multi-scale island and reef remote sensing image mosaic mapping device, characterized in that, The device includes: The image acquisition module is used to acquire the island and reef image files corresponding to each island and reef in the target area. The island and reef image files are high-resolution remote sensing images that have undergone cloud removal processing and are cropped according to the buffer distance with the geometric center of the island and reef as the reference. The image mosaic module is used to stitch together all the island and reef image files within the target area based on the spatial display scale corresponding to the buffer distance, and generate an image mosaic map. An index generation module is used to generate a vector index map that corresponds one-to-one with the geometric position of the image mosaic, wherein the vector index map contains island and reef identification information corresponding to the geometric position of the island and reef. The image overlay module is used to overlay the vector index map onto a predetermined area of ​​the image mosaic map to generate a standardized island and reef thematic map of the target area.

9. An electronic device, comprising: One or more processors; Memory, used to store one or more computer programs. The characteristic feature is that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 7.

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