Method, device and electronic equipment for retrieving astronomical images

Abstract

The present disclosure provides a retrieval method and device of astronomical images and electronic equipment, which can be applied to the technical field of astronomy and the technical field of intelligent retrieval. The retrieval method comprises: determining a to-be-projected image meeting a preset condition from an astronomical image database according to a user-inputted retrieval celestial coordinate and a retrieval radius; performing a tangent plane projection on the retrieval celestial coordinate with the center celestial coordinate of the to-be-projected image as the center to obtain a retrieval projection coordinate; calculating a retrieval pixel coordinate of the retrieval projection coordinate in the to-be-projected image based on a mapping relationship between the projection coordinate and a pixel coordinate of the to-be-projected image; and determining the to-be-projected image as a target astronomical image in the case that the retrieval pixel coordinate and the pixel coordinate of the to-be-projected image exist in intersection in a retrieval pixel circle.

Description

Technical Field

[0001] This disclosure relates to the fields of astronomical technology and intelligent retrieval technology, and more specifically, to a method, apparatus and electronic device for retrieving astronomical images. Background Technology

[0002] With the development of astronomical technology, astronomical observers can take a large number of astronomical images every year using telescopes. Against the backdrop of this massive amount of astronomical images, higher demands are placed on the retrieval of these images.

[0003] In realizing the concept disclosed herein, the inventors discovered at least the following problems in the related technologies: Astronomical optical image retrieval algorithms typically use spherical partitioning algorithms to divide planar rectangular images into sub-regions, resulting in a large amount of distance-related computation during the retrieval process, which leads to low retrieval efficiency for astronomical images. Summary of the Invention

[0004] In view of this, the present disclosure provides a method, apparatus and electronic device for retrieving astronomical images.

[0005] One aspect of this disclosure provides a method for retrieving astronomical images, comprising: determining, based on user-inputted celestial coordinates and a search radius, a target image satisfying preset conditions from an astronomical image database, wherein the preset conditions are determined based on the search radius, and the astronomical image database includes at least one astronomical image; projecting the target celestial coordinates onto a tangent plane using the center celestial coordinates of the target image as the center, to obtain target projection coordinates, wherein the center celestial coordinates are the coordinates of a point located at the center of the target image; calculating the target pixel coordinates of the target projection coordinates in the target image based on the mapping relationship between the projection coordinates and pixel coordinates of the target image; and determining the target astronomical image as the target image if there is an intersection between the pixel coordinates in the target pixel circle and the pixel coordinates of the target image, wherein the target pixel circle is a circle with the target pixel coordinates as the center and the search radius as the radius.

[0006] According to embodiments of this disclosure, the preset conditions include that the area captured by the astronomical image is the target sky region; determining the image to be projected that meets the preset conditions from the astronomical image database based on the user-inputted celestial coordinates and search radius includes: determining the target sky region based on the user-inputted celestial coordinates and search radius; determining an astronomical image set from the astronomical image database, the astronomical image set including at least one regional astronomical image capturing the target sky region. If the celestial coordinates of the regional astronomical image and the searched celestial coordinates meet a preset relative position threshold, the regional astronomical image is determined as the image to be projected. The preset conditions also include that the celestial coordinates of the regional celestial image and the searched celestial coordinates meet the preset relative position threshold.

[0007] According to embodiments of this disclosure, the formula for the target sky region is as follows:

[0008] The celestial coordinates for retrieval are (RA, DEC), where RA represents right ascension, DEC represents declination, and R is the retrieval radius. l DEC1 represents the right ascension of the target sky region, and DEC1 represents the declination of the target sky region.

[0009] According to embodiments of this disclosure, the preset relative position threshold is a great circle distance threshold between the regional celestial coordinates and the retrieved celestial coordinates in the regional astronomical image. The great circle distance threshold is determined based on the size parameters of the astronomical image and the retrieval radius.

[0010] According to embodiments of this disclosure, the formula for the large circle distance threshold is as follows:

[0011] DIST1 <sqrt(W-deg*W-deg+H-deg *H-deg)+R

[0012] DIST1 represents the great circle distance between the regional celestial coordinates and the searched celestial coordinates in the regional astronomical image; sqrt represents the square root; W-deg represents the width W of the regional astronomical image on the sphere; H-deg represents the height H of the regional astronomical image on the sphere; the size parameters include width W and height H; and R represents the search radius.

[0013] According to embodiments of this disclosure, the astronomical image database is established in the following manner: obtaining the representative celestial coordinates of the location points in the astronomical image, wherein the representative celestial coordinates are obtained by inputting the astronomical image into a positioning and recognition model; obtaining the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image; and associating and storing the astronomical image, the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image, and the representative celestial coordinates.

[0014] According to embodiments of this disclosure, the celestial coordinates include the coordinates of a representative position point in an astronomical image, and the representative position point includes the corner position point and the center position point of the astronomical image.

[0015] According to embodiments of this disclosure, the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is obtained as follows: taking the central celestial coordinates of the image to be projected as the center, the representative celestial coordinates of the corner points of the image to be projected are projected onto a tangent plane to obtain the projection coordinates of the corner points; the projection coordinates of the corner points and the pixel coordinates are linearly fitted to obtain the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected.

[0016] Another aspect of this disclosure provides an astronomical image retrieval device, comprising: a first determining module, configured to determine, from an astronomical image database, an image to be projected that meets preset conditions based on retrieval celestial coordinates and a retrieval radius, wherein the preset conditions are determined based on the retrieval radius, and the astronomical image database includes at least one astronomical image; a tangent plane projection module, configured to project the retrieval celestial coordinates onto a tangent plane, centered on the central celestial coordinates of the image to be projected, to obtain retrieval projection coordinates, wherein the central celestial coordinates are the coordinates of a point located at the center of the image to be projected; a calculation module, configured to calculate, based on the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected, the retrieval pixel coordinates in the image to be projected; and a second determining module, configured to determine the image to be projected as the target astronomical image if the retrieval pixel coordinates fall within the range of pixel coordinates of the image to be projected.

[0017] Another aspect of this disclosure provides an electronic device comprising:

[0018] One or more processors;

[0019] Memory, used to store one or more programs.

[0020] When the one or more programs are executed by the one or more processors, the one or more processors implement the method described above.

[0021] Another aspect of this disclosure provides a computer-readable storage medium storing computer-executable instructions that, when executed, are used to implement the method described above.

[0022] Another aspect of this disclosure provides a computer program product including computer-executable instructions that, when executed, are used to implement the method described above.

[0023] According to embodiments of this disclosure, by using the user-input celestial coordinates and search radius, a target image satisfying preset conditions is determined from an astronomical image database, thus narrowing the image retrieval range. Then, using the center celestial coordinates of the target image as the center, the celestial coordinates are projected onto a tangent plane to obtain the projected coordinates. Based on the mapping relationship between the projected coordinates and pixel coordinates of the target image, the target pixel coordinates of the celestial coordinates are quickly calculated, significantly reducing computational load. When there is an intersection between the pixel coordinates in the search pixel circle and the pixel coordinates of the target image, the target image is identified as the astronomical image, improving the efficiency of astronomical image retrieval. Attached Figure Description

[0024] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0025] Figure 1 The diagram schematically illustrates a system architecture diagram of an astronomical image retrieval method applicable according to embodiments of the present disclosure;

[0026] Figure 2 A flowchart illustrating an astronomical image retrieval method according to an embodiment of the present disclosure is shown schematically;

[0027] Figure 3 The diagram illustrates the two-dimensional planar coordinates and three-dimensional spherical coordinates of representative location points according to embodiments of the present disclosure;

[0028] Figure 4 This illustration schematically depicts a process for constructing an astronomical image database according to an embodiment of the present disclosure;

[0029] Figure 5 A schematic diagram illustrating a method for retrieving astronomical images according to another embodiment of the present disclosure is shown.

[0030] Figure 6 A block diagram schematically illustrates an astronomical image retrieval apparatus according to an embodiment of the present disclosure; and

[0031] Figure 7 A block diagram of an electronic device suitable for implementing a method for retrieving astronomical images according to an embodiment of the present disclosure is shown schematically. Detailed Implementation

[0032] The embodiments of the present disclosure 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 the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. 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.

[0034] 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.

[0035] 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.).

[0036] In the embodiments disclosed herein, the collection, updating, analysis, processing, use, transmission, provision, disclosure, and storage of data (e.g., including but not limited to user personal information) comply with relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures have been taken to prevent unauthorized access to user personal information data and to safeguard user personal information security, network security, and national security.

[0037] In the embodiments disclosed herein, user authorization or consent is obtained before acquiring or collecting user personal information.

[0038] Astronomical optical image retrieval algorithms are typically based on star catalog retrieval algorithms. This involves segmenting astronomical images into multiple sub-regions and creating an index. Star catalog retrieval algorithms divide the image into regions based on spherical coordinates of the celestial sphere. Astronomical images, however, are rectangular lattices in planar coordinates, and the relationship between spherical and planar coordinates is non-linear. First, using spherical partitioning algorithms to subdivide the planar rectangular image results in irregularly shaped sub-regions, which are unfavorable for distance calculations. Second, the four sides of a planar rectangle are curves in spherical coordinates, making it difficult for a spherical sub-region to perfectly cover the entire rectangle. Therefore, more sub-regions are needed to cover the whole rectangle, with some sub-regions only partially covering the image, leaving other parts blank. All of these factors negatively impact the efficiency of astronomical image retrieval.

[0039] Therefore, this disclosure proposes a method to transform the problem of determining the intersection of regions when retrieving images using celestial coordinates from the celestial coordinate system to the pixel plane coordinate system. This transformation is based on the projection of the tangent plane onto the celestial coordinates of the image center. Then, in the pixel plane coordinate system, it is determined whether the search region intersects with the image region. If they intersect, the image is considered the target image. This not only simplifies the calculation of the intersection between the search region and the image boundary but also avoids the difficulties in representing the rectangular boundary of the image on the celestial sphere and the computational complexity of intersecting spherical regions when retrieving images using celestial coordinates. Furthermore, to accelerate the retrieval process, the celestial coordinates of the center and four corners are pre-calculated for all astronomical images. During retrieval, a mapping relationship between the projection plane coordinates and the pixel plane coordinates is established based on the coordinates of the center and four corners.

[0040] In view of the above concept, embodiments of this disclosure provide a method for retrieving astronomical images, including: determining a target image from an astronomical image database that meets preset conditions based on user-inputted celestial coordinates and a search radius, wherein the preset conditions are determined based on the search radius, and the astronomical image database includes at least one astronomical image; projecting the celestial coordinates of the target image onto a tangent plane using the center celestial coordinates of the target image as the center, to obtain the target projection coordinates, wherein the center celestial coordinates are the coordinates of a point located at the center of the target image; calculating the target pixel coordinates of the target projection coordinates in the target image based on the mapping relationship between the projection coordinates and pixel coordinates of the target image; and determining the target image as the target astronomical image if there is an intersection between the pixel coordinates in the target pixel circle and the pixel coordinates of the target image.

[0041] Figure 1 A schematic diagram illustrates a system architecture for an astronomical image retrieval method applicable according to embodiments of this disclosure. It should be noted that... Figure 1 The examples shown are merely examples of system architectures that can be applied to the embodiments of this disclosure, in order to help those skilled in the art understand the technical content of this disclosure, but do not mean that the embodiments of this disclosure cannot be used in other devices, systems, environments or scenarios.

[0042] like Figure 1 As shown, the system architecture 100 according to this embodiment may include a first terminal device 101, a second terminal device 102, a third terminal device 103, a network 104, and a server 105. The network 104 serves as a medium for providing communication links between the first terminal device 101, the second terminal device 102, the third terminal device 103, and the server 105. The network 104 may include various connection types, such as wired and / or wireless communication links, etc.

[0043] Users can use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the server 105 via the network 104 to receive or send messages, etc. Various communication client applications can be installed on the first terminal device 101, the second terminal device 102, and the third terminal device 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, and / or social media platform software, etc. (for example only).

[0044] The first terminal device 101, the second terminal device 102, and the third terminal device 103 can be various electronic devices with displays and support web browsing, including but not limited to smartphones, tablets, laptops, and desktop computers.

[0045] Server 105 can be a server that provides various services, such as a backend management server that supports websites browsed by users using the first terminal device 101, the second terminal device 102, and the third terminal device 103 (this is just an example). The backend management server can analyze and process data such as received user requests, and feed back the processing results (such as web pages, information, or data obtained or generated according to user requests) to the terminal devices.

[0046] It should be noted that the astronomical image retrieval method provided in this embodiment can generally be executed by server 105. Correspondingly, the astronomical image retrieval method apparatus provided in this embodiment can generally be located in server 105. The astronomical image retrieval method provided in this embodiment can also be executed by a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Correspondingly, the astronomical image retrieval apparatus provided in this embodiment can also be located in a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Alternatively, the astronomical image retrieval method provided in this embodiment can also be executed by the first terminal device 101, the second terminal device 102, or the third terminal device 103, or by other terminal devices different from the first terminal device 101, the second terminal device 102, or the third terminal device 103. Accordingly, the astronomical image retrieval device provided in this embodiment of the present disclosure may also be set in the first terminal device 101, the second terminal device 102 or the third terminal device 103, or in other terminal devices different from the first terminal device 101, the second terminal device 102 or the third terminal device 103.

[0047] For example, the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected can be originally stored in any one of the first terminal device 101, the second terminal device 102, or the third terminal device 103 (e.g., the first terminal device 101, but not limited thereto), or stored on an external storage device and can be imported into the first terminal device 101. Then, the first terminal device 101 can locally execute the astronomical image retrieval method provided in the embodiments of this disclosure, or send the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected to other terminal devices, servers, or server clusters, and have other terminal devices, servers, or server clusters that receive the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected execute the astronomical image retrieval method provided in the embodiments of this disclosure.

[0048] It should be understood that Figure 1 The number of terminal devices, networks, and servers shown is merely illustrative. Depending on implementation needs, any number of terminal devices, networks, and servers can be included.

[0049] Figure 2 A flowchart illustrating an astronomical image retrieval method according to an embodiment of the present disclosure is shown.

[0050] like Figure 2 As shown, the method includes operations S210~S240.

[0051] In operation S210, based on the user-input celestial coordinates and search radius, an image to be projected that meets preset conditions is determined from the astronomical image database.

[0052] According to embodiments of this disclosure, the astronomical image database includes at least one astronomical image. For example, astronomical images typically depict celestial bodies and phenomena such as stars, planets, galaxies, nebulae, supernova explosions, etc.

[0053] According to embodiments of this disclosure, the preset conditions are determined based on the search radius. For example, the preset conditions may be to use celestial coordinates whose distance from the search celestial coordinates is less than the search radius as the search coordinate range, and to use astronomical images captured within the search coordinate range as the images to be projected.

[0054] In embodiments of this disclosure, user consent or authorization can be obtained before acquiring information such as celestial coordinates and search radius input by the user. For example, a request to obtain user information can be sent to the user before operation S210. Operation S210 is executed if the user consents or authorizes the acquisition of the user-inputted information.

[0055] In operation S220, the retrieval celestial coordinates are tangent-projected onto the center celestial coordinates of the image to be projected, and the retrieval projection coordinates are obtained.

[0056] According to embodiments of this disclosure, the central celestial coordinates are the coordinates of the center point of the image to be projected.

[0057] For example, the celestial coordinates are (RA, DEC), where RA represents right ascension and DEC represents declination.

[0058] Assumptions: The central celestial coordinates of the image to be projected are (RA0, DEC0), where RA0 is the right ascension and DEC0 is the declination. x and y correspond to the abscissa and ordinate of the planar coordinates, respectively.

[0059] Calculate the auxiliary angle △RA = RA - RA0, and then calculate the plane coordinates x and y. The formula is as follows, projecting the retrieved celestial coordinates (RA, DEC) onto the plane coordinates (x, y).

[0060] (1)

[0061] (2)

[0062] In operation S230, based on the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected, the retrieval pixel coordinates of the retrieval projection coordinates in the image to be projected are calculated.

[0063] According to embodiments of this disclosure, a portion of the celestial coordinates in the image to be projected is projected onto a tangent plane to obtain the projected coordinates corresponding to the portion of the celestial coordinates. The linear or non-linear relationship between the projected coordinates corresponding to the portion of the celestial coordinates and the pixel coordinates is analyzed to obtain the mapping relationship between the projected coordinates and the pixel coordinates of the image to be projected.

[0064] According to embodiments of this disclosure, the retrieved projection coordinates can be substituted into the linear or nonlinear relationship between the projection coordinates and pixel coordinates corresponding to a portion of the celestial coordinates to obtain the retrieved pixel coordinates in the image to be projected.

[0065] In operation S240, if there is an intersection between the pixel coordinates in the search pixel circle and the pixel coordinates of the image to be projected, the image to be projected is determined as the target astronomical image.

[0066] According to embodiments of this disclosure, the search pixel circle is a circle with the search pixel coordinates as its center and the search radius as its radius.

[0067] For example, the pixel coordinates of the image to be projected can be in the range of {x∈(0, 450), y∈(0, 600)}. If the pixel coordinates in the search pixel circle include q{x=430, y=300}, then the pixel coordinates in the search pixel circle and the pixel coordinates of the image to be projected intersect.

[0068] According to embodiments of this disclosure, based on the user-inputted celestial coordinates and search radius, a target image satisfying preset conditions is determined from an astronomical image database, thus narrowing the image retrieval range. Then, using the center celestial coordinates of the target image as the center, the retrieval celestial coordinates are projected onto a tangent plane to obtain the retrieval projection coordinates. The retrieval pixel coordinates of the target image can be quickly calculated based on the mapping relationship between the projection coordinates and pixel coordinates of the target image, significantly reducing computational load. When there is an intersection between the pixel coordinates in the retrieval pixel circle and the pixel coordinates of the target image, the target image is identified as the target astronomical image, improving the efficiency of astronomical image retrieval.

[0069] According to embodiments of this disclosure, the celestial coordinates include the coordinates of a representative position point in an astronomical image, and the representative position point includes the corner position point and the center position point of the astronomical image.

[0070] Figure 3 The diagram illustrates the two-dimensional planar coordinates and three-dimensional spherical coordinates of representative location points according to embodiments of the present disclosure.

[0071] like Figure 3 As shown, the left image includes corner points A, B, C, and D, with the center point being CENTER. Two-dimensional planar coordinates represent the positions of these points in the astronomical image. The right image shows the position of these points within the sky region, using three-dimensional spherical coordinates, or celestial coordinates. Celestial coordinates are marked along horizontal or vertical arcs, unlike the horizontal or vertical straight lines of planar coordinates. A quadrilateral astronomical image captures a quadrilateral arc-shaped region.

[0072] According to embodiments of this disclosure, the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is obtained as follows: taking the central celestial coordinates of the image to be projected as the center, the representative celestial coordinates of the corner points of the image to be projected are projected onto a tangent plane to obtain the projection coordinates of the corner points; the projection coordinates of the corner points and the pixel coordinates are linearly fitted to obtain the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected.

[0073] According to embodiments of this disclosure, the projected coordinates of five representative position points can be calculated first, and then a linear fit can be performed between the projected coordinates of the five representative position points and the five pixel coordinates to obtain the mapping relationship between the projected coordinates and pixel coordinates of the image to be projected.

[0074] The database table structure is based on the celestial coordinates of the center and four corners, which is simple and fast in retrieval. The mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is established based on the five-point representation of the celestial coordinates, which is highly understandable and has low computational complexity.

[0075] According to embodiments of this disclosure, the astronomical image database is established in the following manner: obtaining the representative celestial coordinates of the location points in the astronomical image, wherein the representative celestial coordinates are obtained by inputting the astronomical image into a positioning and recognition model; obtaining the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image; and associating and storing the astronomical image, the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image, and the representative celestial coordinates.

[0076] Figure 4 The illustration shows a schematic diagram of constructing an astronomical image database according to an embodiment of the present disclosure.

[0077] like Figure 4 As shown, an astronomical image can be input into a positioning and recognition model to calculate five representative celestial coordinates corresponding to the four corner points and the center point. The representative celestial coordinates of these five points, along with the astronomical image information, are then stored in an image index table.

[0078] Astronomical image information includes the image's identifier, storage path, capture time, image size, and the mapping relationship between the image's projection coordinates and pixel coordinates.

[0079] For example, the fields of the image index table can be: id, path, center_ra, center_dec, top_left_ra, top_left_dec, top_right_ra, top_right_dec, bottom_left_ra, bottom_left_dec, bottom_right_ra, bottom_right_dec.

[0080] Where id is the primary key of the image index table, path is the storage path of the astronomical image, and center_(ra, dec), top_left_(ra, dec), top_right_(ra, dec), bottom_left_(ra, dec), and bottom_right_(ra, dec) are the celestial coordinates of the center point and the four corner points, respectively.

[0081] According to embodiments of this disclosure, the preset conditions include that the area captured by the astronomical image is the target sky region; determining the image to be projected that meets the preset conditions from the astronomical image database based on the user-inputted celestial coordinates and search radius includes: determining the target sky region based on the user-inputted celestial coordinates and search radius; determining an astronomical image set from the astronomical image database, the astronomical image set including at least one regional astronomical image capturing the target sky region. If the celestial coordinates of the regional astronomical image and the searched celestial coordinates meet a preset relative position threshold, the regional astronomical image is determined as the image to be projected. The preset conditions also include that the celestial coordinates of the regional celestial image and the searched celestial coordinates meet the preset relative position threshold.

[0082] According to embodiments of this disclosure, the target sky region can be a quadrilateral arc-shaped region.

[0083] According to embodiments of this disclosure, satisfying the preset relative position threshold can be achieved by ensuring that the relative distance between the region's celestial coordinates and the search celestial coordinates does not exceed the preset relative position threshold, thereby further narrowing the image search range.

[0084] According to embodiments of this disclosure, the search range is narrowed down based on the celestial coordinates and search radius, which can accurately pinpoint the search area.

[0085] The second step involves narrowing the search range based on the relative distance between the celestial coordinates of the searched area and the celestial coordinates of the region, allowing for precise targeting of the images to be searched. For example, it determines whether the relative distance between the celestial coordinates of the region located at the center point and the searched celestial coordinates meets a preset relative position threshold.

[0086] According to embodiments of this disclosure, the formula for the target sky region is as follows:

[0087] (3)

[0088] The celestial coordinates for retrieval are (RA, DEC), where RA represents right ascension, DEC represents declination, and R is the retrieval radius. l DEC1 represents the right ascension of the target sky region, and DEC1 represents the declination of the target sky region.

[0089] According to embodiments of this disclosure, the preset relative position threshold is a great circle distance threshold between the regional celestial coordinates and the retrieved celestial coordinates in the regional astronomical image. The great circle distance threshold is determined based on the size parameters of the astronomical image and the retrieval radius.

[0090] According to embodiments of this disclosure, the formula for the large circle distance threshold is as follows:

[0091] DIST1 <sqrt(W-deg*W-deg+H-deg *H-deg)+R(4)

[0092] DIST1 represents the great circle distance between the regional celestial coordinates and the searched celestial coordinates in the regional astronomical image; sqrt represents the square root; W-deg represents the width W of the regional astronomical image on the sphere; H-deg represents the height H of the regional astronomical image on the sphere; the size parameters include width W and height H; and R represents the search radius.

[0093] Figure 5 A schematic diagram illustrating a method for retrieving astronomical images according to another embodiment of the present disclosure is shown.

[0094] Users input the celestial coordinates (RA, DEC) and search radius R into the astronomical image retrieval platform. The platform then identifies regional astronomical images whose central celestial coordinates (center_(ra, dec)) belong to the target sky region from the image index table. These regional astronomical images belonging to the target sky region are then grouped into an astronomical image set IMG1.

[0095] For each image in the astronomical image set IMG1, calculate the great circle distance DIST1 between the celestial coordinates of the region and the retrieval celestial coordinates in the regional astronomical image. Determine whether the great circle distance DIST1 is less than the great circle distance threshold. If so, include the regional astronomical image in the image set to be projected IMG2; otherwise, treat the regional astronomical image as a non-retrieval image.

[0096] For each image in the image set IMG2 to be projected, the celestial coordinates of the image to be projected are tangent-projected onto a tangent plane to obtain the retrieved projected coordinates. The mapping relationship between the projected coordinates and pixel coordinates of the image to be projected is then retrieved from the image index table. Substituting the retrieved projected coordinates into the mapping relationship formula between the projected coordinates and pixel coordinates of the image to be projected, the retrieved pixel coordinates of the retrieved projected coordinates in the image to be projected are obtained.

[0097] Determine whether there is an intersection between the pixel coordinates in the search pixel circle and the pixel coordinates of the image to be projected. If so, add the image to be projected to the target astronomical image set IMG3; otherwise, treat the image to be projected as a non-search image.

[0098] Return the retrieved target astronomical image set IMG3 to the astronomical image retrieval platform.

[0099] According to embodiments of this disclosure, using the central celestial coordinates of the image to be projected as the center, the representative celestial coordinates of the corner points of the image to be projected are projected onto a tangent plane to obtain the projected coordinates of the corner points. A linear fit is then performed between the projected coordinates of the corner points and the pixel coordinates to obtain the mapping relationship between the projected coordinates and pixel coordinates of the image to be projected. The astronomical image, the mapping relationship between the projected coordinates and pixel coordinates of the astronomical image, and the representative celestial coordinates are then stored in association.

[0100] The database table structure is based on the celestial coordinates of the center and four corners, which is simple and fast in retrieval. The mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is established based on the five points representing the celestial coordinates, which is highly understandable and has low computational complexity.

[0101] Figure 6 A block diagram of an astronomical image retrieval apparatus according to an embodiment of the present disclosure is shown schematically.

[0102] like Figure 6 As shown, the astronomical image retrieval device includes a first determining module 610, a tangent plane projection module 620, a calculation module 630, and a second determining module 640.

[0103] The first determining module 610 is used to determine, based on the user-input celestial coordinates and search radius, an image to be projected that meets preset conditions from an astronomical image database. The preset conditions are determined based on the search radius. The astronomical image database includes at least one astronomical image.

[0104] The tangent plane projection module 620 is used to perform tangent plane projection on the retrieved celestial coordinates with the center celestial coordinates of the image to be projected as the center, so as to obtain the retrieved projected coordinates. The center celestial coordinates are the coordinates of the point located at the center of the image to be projected.

[0105] The calculation module 630 is used to calculate the retrieved pixel coordinates in the image to be projected based on the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected.

[0106] The second determining module 640 is used to determine the image to be projected as the target astronomical image when there is an intersection between the pixel coordinates in the pixel circle and the pixel coordinates of the image to be projected.

[0107] According to embodiments of this disclosure, the first determining module 610 includes a first determining submodule, a second determining submodule, and a third determining submodule. The first determining submodule is used to determine a target sky region based on the user-inputted celestial coordinates and retrieval radius. The second determining submodule is used to determine an astronomical image set from an astronomical image database, the astronomical image set including at least one regional astronomical image capturing the target sky region. The third determining submodule is used to determine the regional astronomical image as the image to be projected if the regional celestial coordinates and the retrieved celestial coordinates in the regional astronomical image satisfy a preset relative position threshold.

[0108] According to embodiments of this disclosure, the preset relative position threshold is a great circle distance threshold between the regional celestial coordinates and the retrieved celestial coordinates in the regional astronomical image. The great circle distance threshold is determined based on the size parameters of the astronomical image and the retrieval radius.

[0109] According to embodiments of this disclosure, the astronomical image database is established in the following manner: obtaining the representative celestial coordinates of the location points in the astronomical image, wherein the representative celestial coordinates are obtained by inputting the astronomical image into a positioning and recognition model; obtaining the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image; and associating and storing the astronomical image, the mapping relationship between the projection coordinates and pixel coordinates of the astronomical image, and the representative celestial coordinates.

[0110] According to embodiments of this disclosure, the celestial coordinates include the coordinates of a representative position point in an astronomical image, and the representative position point includes the corner position point and the center position point of the astronomical image.

[0111] According to embodiments of this disclosure, the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is obtained as follows: taking the central celestial coordinates of the image to be projected as the center, the representative celestial coordinates of the corner points of the image to be projected are projected onto a tangent plane to obtain the projection coordinates of the corner points; the projection coordinates of the corner points and the pixel coordinates are linearly fitted to obtain the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected.

[0112] Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure, or at least part of the functions of any one or more of them, can be implemented in one module. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure can be implemented by dividing them into multiple modules. Any one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure 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-Chip, a System-on-a-Substrate, a System-on-Package, an Application-Specific Integrated Circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, one or more of the modules, submodules, units, and subunits according to embodiments of the present disclosure can be at least partially implemented as computer program modules, which, when run, can perform corresponding functions.

[0113] For example, any plurality of the first determining module 610, the tangent plane projection module 620, the calculation module 630, and the second determining module 640 can be combined into one module / unit / subunit, or any one of these modules / units / subunits can be split into multiple modules / units / subunits. Alternatively, at least part of the functionality of one or more of these modules / units / subunits can be combined with at least part of the functionality of other modules / units / subunits and implemented in one module / unit / subunit. According to embodiments of this disclosure, at least one of the first determining module 610, the tangent plane projection module 620, the calculation module 630, and the second determining module 640 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 first determining module 610, the tangent plane projection module 620, the calculation module 630, and the second determining module 640 may be at least partially implemented as a computer program module, which can perform corresponding functions when the computer program module is run.

[0114] It should be noted that the astronomical image retrieval device in the embodiments of this disclosure corresponds to the astronomical image retrieval method in the embodiments of this disclosure. The description of the astronomical image retrieval device is specifically referred to in the astronomical image retrieval method section, and will not be repeated here.

[0115] Figure 7 A block diagram of an electronic device suitable for implementing a method for retrieving astronomical images according to an embodiment of the present disclosure is shown schematically. Figure 7 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0116] like Figure 7 As shown, an electronic device 700 according to an embodiment of the present disclosure includes a processor 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 702 or a program loaded from a storage portion 708 into a random access memory (RAM) 703. The processor 701 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 701 may also include onboard memory for caching purposes. The processor 701 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0117] RAM 703 stores various programs and data required for the operation of electronic device 700. Processor 701, ROM 702, and RAM 703 are interconnected via bus 704. Processor 701 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 702 and / or RAM 703. It should be noted that the programs may also be stored in one or more memories other than ROM 702 and RAM 703. Processor 701 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.

[0118] According to embodiments of this disclosure, the electronic device 700 may further include an input / output (I / O) interface 705, which is also connected to a bus 704. The electronic device 700 may also include one or more of the following components connected to the input / output (I / O) interface 705: an input section 706 including a keyboard, mouse, etc.; an output section 707 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN card, modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the input / output (I / O) interface 705 as needed. A removable medium 711, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 710 as needed so that computer programs read from it can be installed into the storage section 708 as needed.

[0119] According to embodiments of this disclosure, the method flow according to embodiments of this disclosure can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via communication section 709, and / or installed from removable medium 711. When the computer program is executed by processor 701, it performs the functions defined in the system of embodiments of this disclosure. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0120] This disclosure 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 that, when executed, implement the method according to the embodiments of this disclosure.

[0121] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. Examples include, but are 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 disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0122] For example, according to embodiments of this disclosure, a computer-readable storage medium may include the ROM 702 and / or RAM 703 described above and / or one or more memories other than ROM 702 and RAM 703.

[0123] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods provided in the embodiments of this disclosure. When the computer program product is run on an electronic device, the program code enables the electronic device to implement the astronomical image retrieval method provided in the embodiments of this disclosure.

[0124] When the computer program is executed by the processor 701, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0125] 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 709, and / or installed from a removable medium 711. 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.

[0126] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure 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 execute entirely on a user's computing device, partially on a 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).

[0127] 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 the present disclosure. 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. Those skilled in the art will understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments of this disclosure may be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0128] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for retrieving astronomical images, comprising: Based on the user-input celestial coordinates and search radius, an image to be projected that meets preset conditions is determined from an astronomical image database. The preset conditions are determined based on the search radius. The astronomical image database includes at least one astronomical image. Using the center celestial coordinates of the image to be projected as the center, the retrieved celestial coordinates are projected onto a tangent plane to obtain the retrieved projected coordinates. The center celestial coordinates are the coordinates of the point located at the center of the image to be projected. Based on the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected, the retrieved pixel coordinates in the image to be projected are calculated. If the pixel coordinates in the search pixel circle intersect with the pixel coordinates of the image to be projected, the image to be projected is determined as the target astronomical image. The search pixel circle is a circle with the search pixel coordinates as its center and the search radius as its radius.

2. The method according to claim 1, characterized in that, The preset conditions include that the area captured by the astronomical image is the target sky area; The step of determining the image to be projected from the astronomical image database that meets preset conditions based on the user-input celestial coordinates and search radius includes: The target sky region is determined based on the celestial coordinates and search radius input by the user. An astronomical image set is determined from the astronomical image database, the astronomical image set including at least one regional astronomical image of the target sky region; If the celestial coordinates of the region in the regional astronomical image and the retrieval celestial coordinates satisfy a preset relative position threshold, the regional astronomical image is determined as the image to be projected. The preset condition also includes that the celestial coordinates of the region and the retrieval celestial coordinates satisfy the preset relative position threshold.

3. The method according to claim 2, characterized in that, The formula for the target sky region is as follows: The celestial coordinates for the search are (RA, DEC), where RA represents the right ascension, DEC represents the declination, and R is the search radius. l DEC1 represents the right ascension of the target sky region, and DEC1 represents the declination of the target sky region.

4. The method according to claim 2, characterized in that, The preset relative position threshold is the great circle distance threshold between the regional celestial coordinates in the regional astronomical image and the searched celestial coordinates. The great circle distance threshold is determined based on the size parameters of the astronomical image and the search radius.

5. The method according to claim 4, wherein the formula for the large circle distance threshold is as follows: DIST1 <sqrt(W-deg*W-deg+H-deg *H-deg)+R DIST1 represents the great circle distance between the regional celestial coordinates in the regional astronomical image and the searched celestial coordinates, sqrt represents the square root, W-deg represents the width W of the regional astronomical image on the sphere, H-deg represents the height H of the regional astronomical image on the sphere, the size parameters include the width W and the height H, and R represents the search radius.

6. The method according to claim 1, characterized in that, The astronomical image database was established based on the following method: Obtain the representative celestial coordinates of the location point in the astronomical image, wherein the representative celestial coordinates are obtained by inputting the astronomical image into the positioning and recognition model; Obtain the mapping relationship between the projected coordinates and the pixel coordinates of the astronomical image; The astronomical image, the mapping relationship between the projected coordinates and pixel coordinates of the astronomical image, and the coordinates representing the celestial sphere are stored together.

7. The method according to claim 6, characterized in that, The representative celestial coordinates include the coordinates of the representative position points in the astronomical image, and the representative position points include the corner positions and the center position points of the astronomical image.

8. The method according to claim 7, characterized in that, The mapping relationship between the projection coordinates and pixel coordinates of the image to be projected is obtained based on the following method: Using the central celestial coordinates of the image to be projected as the center, the representative celestial coordinates of the corner points located in the image to be projected are projected onto a tangent plane to obtain the projected coordinates of the corner points; By performing linear fitting on the projected coordinates and pixel coordinates of the corner points, the mapping relationship between the projected coordinates and pixel coordinates of the image to be projected is obtained.

9. An astronomical image retrieval device, comprising: The first determining module is used to determine, based on the user-input celestial coordinates and retrieval radius, an image to be projected that meets preset conditions from an astronomical image database. The preset conditions are determined based on the retrieval radius. The astronomical image database includes at least one astronomical image. The tangent plane projection module is used to project the retrieved celestial coordinates onto the tangent plane with the center celestial coordinates of the image to be projected as the center, so as to obtain the retrieved projection coordinates. The center celestial coordinates are the coordinates of the center position point of the image to be projected. The calculation module is used to calculate the retrieved pixel coordinates of the retrieved projection coordinates in the image to be projected based on the mapping relationship between the projection coordinates and pixel coordinates of the image to be projected. The second determining module is used to determine the image to be projected as the target astronomical image when there is an intersection between the pixel coordinates in the search pixel circle and the pixel coordinates of the image to be projected. The search pixel circle is a circle with the search pixel coordinates as the center and the search radius as the radius.

10. An electronic device, comprising: One or more processors; Memory, used to store one or more programs. Wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the method of any one of claims 1 to 8.

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