Method for matching oblique photograph image and land parcel, electronic device and storage medium

Abstract

The application provides a matching method of oblique photography image and land, an electronic device and a storage medium, and the method comprises the following steps: acquiring a land line map layer and an unmanned aerial vehicle (UAV) flight height based on an image obtained by UAV oblique photography; outputting a center point coordinate of a target land based on the land line map layer; selecting and outputting a candidate image from the image according to the center point coordinate and the flight height; outputting a partial vector of a ground projection of a unit vector of a photography main optical axis of the candidate image according to an external orientation element of the candidate image; selecting a plurality of images with the smallest angle and matching the images with the target land according to an included angle between the partial vector and a vector from a photography center of the candidate image to the center point coordinate of the target land; and repeating the above selection step until matching is completed for all lands. The method processes the external orientation element of the image, thereby saving repeated photography work, and has the beneficial effects of saving processes and improving efficiency.

Description

Technical Field

[0001] This invention relates to the field of real estate information management technology, and in particular to a method for matching oblique photography images with land parcels, electronic devices, and storage media. Background Technology

[0002] In the registration and confirmation of real estate rights, such as land and building ownership, it is often necessary to match on-site photos for each land parcel to obtain information about the land parcel's interior and exterior and to improve the land parcel data. Traditionally, obtaining land parcel photos usually involves manual on-site photography, which is not only inefficient but also requires a large amount of external work. Nowadays, oblique photogrammetry has become the main method for topographic mapping. Photos of each land parcel are already included in the oblique photogrammetry imagery. If the oblique photogrammetry imagery can be directly matched with each land parcel, the need for manual photography can be eliminated, effectively improving the efficiency of information processing. Summary of the Invention

[0003] In view of the above, this application proposes a method, electronic device and storage medium for matching oblique photography images with land parcels to solve the above problems.

[0004] This application provides a method for matching oblique photography images with land parcels, including the following steps:

[0005] S10: Obtain the parcel line layer, as well as the imagery and drone flight altitude based on UAV oblique photography;

[0006] S20: Based on the parcel line layer, output the coordinates of the center point of the target parcel;

[0007] S30: Based on the center point coordinates and the flight altitude, filter and output candidate images from the images;

[0008] S40: Based on the outward orientation elements of the candidate images, output the component vector of the unit vector of the principal optical axis of the candidate images projected onto the ground.

[0009] S50: Based on the angle between the sub-vector and the vector from the center of the candidate image to the center point of the target parcel, select several images with the smallest angle and match them with the target parcel.

[0010] S60: Repeat steps S20 to S50 until all parcels have been matched.

[0011] In at least one embodiment, step S20 further includes:

[0012] The coordinates of the center point of the target land parcel are output using the following formula:

[0013]

[0014]

[0015] in, Let x be the coordinates of the center point of the target parcel. i y i Let n be the coordinates of each boundary point of the target parcel, n be the number of boundary points of the target parcel, and i be the boundary point number of the target parcel.

[0016] In at least one embodiment, step S30 further includes:

[0017] The ground projection length of the distance between the image's photographic center and the center point of the target parcel is D, and the flight altitude is H. The candidate images are selected using the following formula:

[0018] mH-l≤D≤mH+l (3)

[0019] Where m is the tilt coefficient, which depends on the camera tilt angle of the drone's tilt photography, and l is the distance fluctuation value.

[0020] In at least one embodiment, step S30 is followed by:

[0021] S31: Remove the downward view image from the candidate images.

[0022] In at least one embodiment, step S31 further includes:

[0023] Images that satisfy the following formula are considered as downward-viewing images:

[0024] 180°-p≤|ω|≤180°+p (4)

[0025] Where ω is the roll angle of the image, and p is the angle fluctuation value.

[0026] In at least one embodiment, step S40 further includes:

[0027] Based on the exterior orientation elements of the candidate images, the component vector of the unit vector of the principal optical axis of the candidate images projected onto the ground is output by the following formula.

[0028]

[0029]

[0030]

[0031] Where, ω, k represents the roll, pitch, and yaw angles from the exterior orientation elements of the candidate image, and R is the rotation matrix. Let be the vector of the principal optical axis of the candidate image. The vertical component vector of the principal optical axis of the candidate image.

[0032] In at least one embodiment, step S50 further includes:

[0033] The included angle θ is output by the following formula:

[0034]

[0035] The smallest of the candidate images are selected and matched with the target parcel.

[0036] In at least one embodiment, step S50 further includes:

[0037] The q images with the smallest included angle θ are selected to match the target parcel, where 2≤q≤5.

[0038] This application also proposes an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the method for matching oblique photography images with land parcels as described above.

[0039] This application also proposes a computer-readable storage medium comprising a stored computer program, wherein the computer program, when running, controls the device containing the computer-readable storage medium to perform the oblique photogrammetry image and parcel matching method as described above.

[0040] Compared with the prior art, the method for matching oblique photogrammetry images with land parcels proposed in this application extracts and processes the exterior orientation elements in the images obtained by oblique photogrammetry, thereby achieving the purpose of screening existing survey images and matching them with corresponding land parcels, eliminating repetitive photography work, and having the beneficial effects of saving procedures and improving efficiency. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating the steps of an embodiment of the method for matching oblique photography images with land parcels in this application.

[0042] Figure 2 yes Figure 1 A schematic diagram of the side position of the oblique photography in the method of matching the oblique photography image with the land parcel.

[0043] Figure 3 yes Figure 1 A schematic diagram of the stereo coordinates of the oblique photography in the method of matching the oblique photography images with the land parcels.

[0044] Figure 4 yes Figure 1 The diagram shows the position of the center point of the oblique photography relative to the target parcel in the ground projection of the image and the parcel matching method shown.

[0045] Figure 5 yes Figure 1 The diagram shows the orientation of some exterior orientation elements in the oblique photography image in the method of matching oblique photography images with land parcels. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0048] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0050] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0051] Please see Figure 1 This invention proposes a method for matching oblique photography images with land parcels, comprising the following steps:

[0052] S10: Obtain the parcel line layer, as well as the imagery and drone flight altitude based on UAV oblique photography;

[0053] S20: Based on the parcel line layer, output the coordinates of the center point of the target parcel;

[0054] S30: Select and output candidate images from the images based on the center point coordinates and flight altitude;

[0055] S40: Based on the outward orientation elements of the candidate image, output the unit vector of the principal optical axis of the candidate image and the component vector of its ground projection.

[0056] S50: Based on the angle between the sub-vector and the vector from the center of the candidate image to the center point of the target parcel, select several images with the smallest angle and match them with the target parcel.

[0057] S60: Repeat steps S20 to S50 until all parcels have been matched.

[0058] It needs to be explained that in real estate registration, each parcel of land requires corresponding image data. Oblique photogrammetry using drones is a surveying operation. Currently, drones equipped with cameras are typically used to photograph the surrounding parcels along a predetermined flight path. The acquired images automatically record external orientation elements, such as the coordinates of the shooting center and its rotation angle relative to those coordinates. The shooting center refers to the position of the camera's focal point when the image is captured. During the shooting process, the drone's flight path is usually M or Z-shaped, traversing all parcels fully, completely, and from multiple angles through reversal. This provides the basis for reusing surveying images in real estate registration in this embodiment.

[0059] In this embodiment, the drone is equipped with five cameras in fixed positions. Four of them are arranged at adjacent angles of 90° and at 45° angles to the vertically downward direction of the plumb bob. The other camera is positioned in the vertically downward direction of the plumb bob.

[0060] In step S10, the land parcel line layer includes the distribution and specific coordinates of each land parcel. The land parcel line layer can be obtained directly from survey data or by organizing and analyzing oblique photogrammetry data.

[0061] The exterior orientation elements include six X's. S ,Y S Z S ,ω, k, the first three parameters are the three-dimensional coordinates of the camera center when the image was captured, and the last three parameters are the rotation angles of the principal optical axis direction relative to the three coordinate axes of the coordinate system during shooting, called the roll angle ω, pitch angle ω, and pitch angle respectively. For details regarding the heading angle k, please refer to [reference needed]. Figure 5 As shown.

[0062] In one embodiment, step S20 further includes:

[0063] The coordinates of the center point of the target land parcel are output using the following formula:

[0064]

[0065]

[0066] in, Let x be the coordinates of the center point of the target parcel. i y i Let n be the coordinates of each boundary point of the target parcel, n be the number of boundary points of the target parcel, and i be the boundary point number of the target parcel.

[0067] It should be noted that the boundary of a lot is the boundary line of each lot. The boundary points mentioned in this application are the intersection points of the boundary lines of each lot. For example, if the lot is rectangular, the boundary points are the coordinates of the four corners of the rectangle. Step S20 obtains the center point coordinates of the target lot by averaging the coordinates of the boundary points. The target lot is one of the lots selected from all lots for matching processing. Since this method will traverse all lots in sequence through steps S20 to S50 to complete the entire matching process, the selection of the target lot can be regular or random, aiming to finally complete the matching of all lots.

[0068] Please refer to Figure 2 , in one embodiment, step S30 further includes:

[0069] The ground projection length of the distance between the camera center of the image and the center point coordinates of the target lot is D, and the flight height is H. The alternative images are screened by the following formula:

[0070] mH - l ≤ D ≤ mH + l (3)

[0071] Where, m is the tilt coefficient, which depends on the tilt angle of the camera of the UAV oblique photography, and l is the distance floating value. In this embodiment, since the tilt angle of the camera is 45° when the UAV performs oblique photography, the tilt coefficient m = 1, and l is taken as 10. Substituting into formula (3) gives H - 10 < D < H + 10 to obtain the alternative images.

[0072] In one embodiment, after step S30, it further includes:

[0073] S31: Exclude the nadir image in the alternative images.

[0074] Step S31 further screens the images, mainly excluding the images taken by the downward-set camera. Since this part of the images is obtained by the vertically downward-set camera, the images often cannot cover an entire complete lot, so they are removed to make the selected images more likely to include a complete lot and improve the image quality.

[0075] In one embodiment, step S31 further includes:

[0076] The images that satisfy the following formula are regarded as nadir images:

[0077] 180° - p ≤ |ω| ≤ 180° + p (4)

[0078] Where ω is the roll angle of the image, and p is the angle fluctuation value. If the camera shoots vertically downwards, the roll angle ω in the exterior orientation element of the obtained image will be -180° or +180°. Considering the error and fluctuation, downward-shot images can be discarded. In this embodiment, the angle fluctuation value p is taken as 5°, that is, images that satisfy 175°≤|ω|≤185° are considered downward-view images and are discarded.

[0079] Please see Figure 3 In one embodiment, step S40 further includes:

[0080] Based on the exterior orientation elements of the candidate images, the component vector of the unit vector of the principal optical axis of the candidate images projected onto the ground is output using the following formula.

[0081]

[0082]

[0083]

[0084] Where, ω, k represents the roll, pitch, and yaw angles from the exterior orientation elements of the candidate image, and R is the rotation matrix. The vector of the principal optical axis of the candidate images. X is the vertical component of the principal optical axis of the candidate image. tp Y tp Z tp These represent the three direction axes of the coordinate system. Please continue reading. Figures 2 to 4 Let S be the center point of the photograph, N be the projection point of the photograph center onto the ground, and C be the center point coordinates of the target land parcel. Using equations (5) and (6), the output can be... Two-dimensional vector projected onto the ground

[0085] Please see Figure 4 In one embodiment, step S50 further includes:

[0086] The included angle θ is output using the following formula:

[0087]

[0088] Select the smallest candidate images and match them with the target parcel.

[0089] By comparing the included angle θ, it can be seen that a smaller included angle θ means that the direction of the candidate image is closest to the target parcel, and it also means that the image has a higher probability of encompassing the entire target parcel. Therefore, the candidate images with the smallest included angle θ can be considered as the most matching parcel images.

[0090] In one embodiment, step S50 further includes:

[0091] Select the q images with the smallest included angle θ to match the target parcel, where 2≤q≤5.

[0092] In this embodiment, after selecting several images with the smallest included angle θ, further filtering can be performed manually. Therefore, the value of q is between 2 and 5. This is because even if the selected images have the smallest included angle θ and are closest to the desired image, they may not completely encompass the entire parcel, or the viewing angle may not be as good as images with slightly larger included angles. Therefore, manual intervention in the filtering process further improves the accuracy of the final result. Alternatively, the value of q can be set to 1, in which case no manual intervention is required, and the image with the smallest included angle θ is directly matched with the target parcel.

[0093] Finally, step S60 is performed to screen and match all land parcels to complete the preliminary work of image recording in real estate registration.

[0094] In one embodiment, for the matched images, the boundary lines of the parcels are drawn on the candidate images selected in step S50 based on the parcel line layer. In this embodiment, the boundary lines of the parcels are marked with red lines on the images to identify the target parcels.

[0095] This application also proposes an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the above-described method for matching oblique photographic images with land parcels.

[0096] The electronic device may be a desktop computer, laptop, handheld computer, or smart tablet, etc. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the above components are merely examples of electronic devices and do not constitute a limitation on the electronic device. It may include more or fewer components than described above, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0097] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0098] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0099] This application also proposes a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the above-described method for matching oblique photographic images with land parcels.

[0100] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the above embodiments is stored, and the electronic device of the system or apparatus may read and execute the program code stored in the storage medium.

[0101] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute a part of this specification.

[0102] Examples of storage media used to provide program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW), magnetic tapes, non-volatile memory cards, and ROMs. Optionally, it may also include downloading program code from a server computer via a communication network.

[0103] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0104] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0105] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be incorporated into the present invention.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for matching oblique photography images with land parcels, characterized in that, Includes the following steps: S10: Obtain the parcel line layer, as well as the imagery and drone flight altitude based on UAV oblique photography; S20: Based on the parcel line layer, output the coordinates of the center point of the target parcel; S30: Based on the center point coordinates and the flight altitude, filter and output candidate images from the images; step S30 further includes: the ground projection length of the distance between the photography center of the image and the center point coordinates of the target parcel is D, the flight altitude is H, and the candidate images are filtered using the following formula: in, m The tilt coefficient depends on the camera tilt angle used for tilt photography by the drone. l This is a distance-floating value; S40: Based on the outward orientation elements of the candidate images, output the component vector of the unit vector of the principal optical axis of the candidate images projected onto the ground. S50: Based on the angle between the sub-vector and the vector from the center of the candidate image to the center point of the target parcel, select several images with the smallest angle and match them with the target parcel; step S50 further includes: outputting the angle using the following formula. : in, The component vector of the photographic principal optical axis of the candidate image on the ground projection; Step S50 further includes: filtering out the included angle. smallest q One image is matched with the target parcel, where 2 ≤ q ≤5; S60: Repeat steps S20 to S50 until all parcels have been matched.

2. The method for matching oblique photography images with land parcels as described in claim 1, characterized in that, Step S20 further includes: The coordinates of the center point of the target land parcel are output using the following formula: （1） （2） in, , The coordinates of the center point of the target land parcel are: , The coordinates of each boundary point of the target parcel. n The number of boundary points of the target land parcel. i Number the boundary points of the target parcel.

3. The method for matching oblique photography images with land parcels as described in claim 1, characterized in that, The step S30 is followed by: S31: Remove the downward view image from the candidate images.

4. The method for matching oblique photography images with land parcels as described in claim 3, characterized in that, Step S31 further includes: Images that satisfy the following formula are considered as downward-viewing images: （4） in, The roll angle of the image. p This is a floating angle value.

5. The method for matching oblique photography images with land parcels as described in claim 1, characterized in that, Step S40 further includes: Based on the exterior orientation elements of the candidate images, the component vector of the unit vector of the principal optical axis of the candidate images projected onto the ground is output by the following formula. : （5） （6） （7） in, These represent the roll, pitch, and yaw angles from the exterior orientation elements of the candidate image, respectively, with R being the rotation matrix. Let be the vector of the principal optical axis of the candidate image. The vertical component vector of the principal optical axis of the candidate image.

6. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method for matching oblique photography images with land parcels as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the method for matching oblique photogrammetry images with land parcels as described in any one of claims 1 to 5.

Images