A method and device for generating orthophotos of field archaeological excavation test squares

Abstract

The present invention relates to a method and device for generating orthophotos of a field archaeological excavation probe, and belongs to the field of image processing technology. The method comprises: obtaining a panoramic video of a target area collected by a panoramic camera and a laser point cloud of the target area collected by a laser radar; generating a digital elevation model of the target area based on the laser point cloud, and performing time synchronization on the panoramic video and the laser point cloud; extracting frames from the panoramic video, and determining the position and posture of each frame image extracted from the panoramic video based on the time synchronization result of the panoramic video and the laser point cloud; generating a digital orthophoto of the target area based on the digital elevation model and the position and posture of each frame image extracted from the panoramic video. The present invention ensures measurement accuracy while achieving all-round spatial data acquisition of the target area, and improves the efficiency of data acquisition through a convenient image processing process.

Description

Technical Field

[0001] The present invention relates to the technical field of image processing, and in particular to a method and device for generating orthophotos of field archaeological excavation test pits. Background Art

[0002] In field archaeological excavations, records of relics are often drawn manually by archaeologists or after measurement with a total station. Manual drawing can quickly obtain the main structure of the relics, but the record of the relics is subject to a large number of subjective factors and the accuracy is not high. Although total stations and other measuring equipment can provide more accurate measurement results, they are inconvenient to operate in the complex environment of the archaeological site, and it takes a lot of time to complete the record of the entire ruins.

[0003] Existing methods cannot quickly obtain all-round spatial data, resulting in a waste of time and human resources in the excavation process, and prolonging the exposure time of the relics in the air, which is not conducive to the protection of the relics. Therefore, how to quickly obtain all-round spatial data of the relics and improve the measurement efficiency while ensuring the measurement accuracy has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of this, it is necessary to provide a method and device for generating orthophotos of field archaeological excavation trenches, so as to solve the problem of low efficiency in acquiring spatial data of relics during the current field archaeological excavation trenches.

[0005] In order to solve the above problems, the present invention provides a method for generating orthophotos of field archaeological excavation test squares, comprising:

[0006] Acquire a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar;

[0007] Generating a digital elevation model of the target area based on the laser point cloud, and performing time synchronization between the panoramic video and the laser point cloud;

[0008] Extract frames from the panoramic video, and determine the pose of each frame of the image extracted from the panoramic video based on a time synchronization result between the panoramic video and the laser point cloud;

[0009] A digital orthophoto of the target area is generated based on the digital elevation model and the position and posture of each frame of the image extracted from the panoramic video.

[0010] In a possible implementation, the performing time synchronization on the panoramic video and the laser point cloud includes:

[0011] Acquire first inertial measurement unit data corresponding to the panoramic video and second inertial measurement unit data corresponding to the laser point cloud;

[0012] The panoramic video and the laser point cloud are time synchronized based on a target time difference, where the target time difference is a difference between a timestamp corresponding to a maximum value in the first inertial measurement unit data and a timestamp corresponding to a maximum value in the second inertial measurement unit data.

[0013] In a possible implementation, determining the position and posture of each frame of the image extracted from the panoramic video based on the time synchronization result of the panoramic video and the laser point cloud includes:

[0014] Determine the timestamp of each frame of image extracted from the panoramic video in the laser point cloud based on the target time difference and the timestamp of each frame of image extracted from the panoramic video in the panoramic video;

[0015] Based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud, the pose of each frame of image extracted from the panoramic video is determined.

[0016] In a possible implementation, determining the pose of each frame of image extracted from the panoramic video based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud includes:

[0017] The pose of each frame of image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame of image extracted from the panoramic video.

[0018] In a possible implementation, determining the pose of each frame of image extracted from the panoramic video based on the pose of the laser radar corresponding to the timestamp of each frame of image extracted from the panoramic video in the laser point cloud includes:

[0019] The pose of each frame image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame image extracted from the panoramic video, and the transformation matrix from the laser radar coordinate system to the panoramic camera coordinate system.

[0020] In a possible implementation, generating a digital elevation model of the target area based on the laser point cloud includes:

[0021] The laser point cloud is denoised, and a digital elevation model of the target area is generated based on the denoised laser point cloud.

[0022] In a possible implementation, the method further includes:

[0023] After the digital orthophoto of the target area is generated, the target digital orthophoto is derived based on a preset accuracy.

[0024] The present invention also provides an orthophoto generating device for field archaeological excavation test squares, comprising:

[0025] An acquisition module, used to acquire a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar;

[0026] A synchronization module, used to generate a digital elevation model of the target area based on the laser point cloud, and to perform time synchronization between the panoramic video and the laser point cloud;

[0027] A determination module, configured to extract frames from the panoramic video, and determine the pose of each frame of the image extracted from the panoramic video based on a time synchronization result between the panoramic video and the laser point cloud;

[0028] A generation module is used to generate a digital orthophoto of the target area based on the digital elevation model and the pose of each frame of the image extracted from the panoramic video.

[0029] The present invention also provides an electronic device, including a memory and a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the orthophoto generation method of the field archaeological excavation pit as described above is implemented.

[0030] The present invention also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for generating orthophotos of field archaeological excavation pits as described above is implemented.

[0031] The beneficial effects of the present invention are as follows: the orthophoto generation method and device for field archaeological excavation probe provided by the present invention first obtain a panoramic video and a laser point cloud of a target area to provide basic data for subsequent image processing, then generate a DEM of the target area through the laser point cloud of the target area, thereby determining the terrain changes of the target area, and then determine the position and posture of each frame image extracted from the panoramic video by time synchronization of the panoramic video and the laser point cloud, thereby determining the surface spatial geometric features of the target area, and finally generate a DOM of the target area according to the DEM and the position and posture of each frame image extracted from the panoramic video, thereby realizing the acquisition of all-round spatial data of the target area. While realizing the acquisition of all-round spatial data of the target area, the present invention ensures measurement accuracy and improves data acquisition efficiency through a convenient image processing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A schematic flow chart of an embodiment of a method for generating orthophotos of a field archaeological excavation pit provided by the present invention;

[0033] Figure 2 A schematic diagram of a process flow of an embodiment of an orthophoto generation process provided by the present invention;

[0034] Figure 3 A schematic structural diagram of an embodiment of an orthophoto generation device for field archaeological excavation probe provided by the present invention;

[0035] Figure 4 A schematic structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0037] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In the description of the present invention, reference to an "embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the described embodiments may be combined with other embodiments.

[0039] In field archaeological excavations, records of relics are often drawn manually by archaeologists or after measurement with a total station. Manual drawing can quickly obtain the main structure of the relics, but the record of the relics is subject to a large number of subjective factors and the accuracy is not high. Although total stations and other measuring equipment can provide more accurate measurement results, they are inconvenient to operate in the complex environment of the archaeological site, and it takes a lot of time to complete the record of the entire ruins.

[0040] Existing methods are unable to quickly obtain comprehensive spatial data, resulting in a waste of time and human resources during the excavation process, and prolonging the exposure time of the relics to the air, which is not conducive to the protection of the relics.

[0041] In order to solve the above problems, the present invention provides a method for generating orthophotos of field archaeological excavation pits.

[0042] The specific embodiments are described in detail below:

[0043] A specific embodiment of the present invention discloses a method for generating orthophotos of field archaeological excavation probes, combining Figure 1 Come and see, Figure 1 The flowchart of an embodiment of a method for generating orthophotos of a field archaeological excavation pit provided by the present invention includes steps S101 to S104, wherein:

[0044] In step S101, a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar are obtained;

[0045] In step S102, a digital elevation model of the target area is generated based on the laser point cloud, and the panoramic video and the laser point cloud are time synchronized;

[0046] In step S103, the panoramic video is frame extracted, and the position and posture of each frame image extracted from the panoramic video is determined based on the time synchronization result of the panoramic video and the laser point cloud;

[0047] In step S104, a digital orthophoto of the target area is generated based on the digital elevation model and the pose of each frame of the image extracted from the panoramic video.

[0048] During implementation, we can first obtain the panoramic video of the target area collected by the panoramic camera and the laser point cloud of the target area collected by the lidar. When collecting data, we can use the integrated panoramic camera and lidar equipment to slowly shoot along the established path within the field archaeological scope to ensure stable and accurate data collection of the target area.

[0049] Then, a digital elevation model (DEM) of the target area can be generated based on the acquired laser point cloud. For example, the DEM of the target area can be generated using open source software such as QGis, so as to determine the terrain changes in the target area. At the same time, the panoramic video and the laser point cloud can be synchronized in time, that is, the correspondence between the timestamps of the data points in the panoramic video and the timestamps of the data points in the laser point cloud can be determined.

[0050] Then, the acquired panoramic video can be framed. For example, the frame-sampling interval can be determined according to the walking speed of the photographer when the panoramic video is captured, and then the panoramic video can be framed. Then, the position and posture of each frame extracted from the panoramic video can be determined through the time synchronization result of the panoramic video and the laser point cloud, so as to determine the surface spatial geometric characteristics of the target area.

[0051] Finally, the digital orthophoto map (DOM) of the target area can be generated according to the DEM and the pose of each frame image extracted from the panoramic video, and the all-round spatial data of the target area can be obtained.

[0052] Compared with the prior art, the orthophoto generation method of the field archaeological excavation probe provided in the present embodiment first obtains a panoramic video and a laser point cloud of the target area to provide basic data for subsequent image processing, then generates a DEM of the target area through the laser point cloud of the target area, thereby determining the terrain changes of the target area, and then determines the position and posture of each frame image extracted from the panoramic video by time synchronization of the panoramic video and the laser point cloud, thereby determining the surface spatial geometric features of the target area, and finally generates a DOM of the target area according to the DEM and the position and posture of each frame image extracted from the panoramic video, thereby realizing the acquisition of all-round spatial data of the target area. While realizing the acquisition of all-round spatial data of the target area, the present invention ensures measurement accuracy and improves data acquisition efficiency through a convenient image processing process.

[0053] Exemplarily, the performing time synchronization on the panoramic video and the laser point cloud includes:

[0054] Acquire first inertial measurement unit data corresponding to the panoramic video and second inertial measurement unit data corresponding to the laser point cloud;

[0055] The panoramic video and the laser point cloud are time synchronized based on a target time difference, where the target time difference is a difference between a timestamp corresponding to a maximum value in the first inertial measurement unit data and a timestamp corresponding to a maximum value in the second inertial measurement unit data.

[0056] Specifically, when time synchronization is performed on the panoramic video and the laser point cloud, the first inertial measurement unit (IMU) data corresponding to the panoramic video and the second IMU data corresponding to the laser point cloud can be first obtained, and then the timestamp corresponding to the maximum value in the first IMU data and the second IMU data is determined, and the difference dt (i.e., the target time difference) between the timestamp corresponding to the maximum value in the first IMU data and the timestamp corresponding to the maximum value in the second IMU data is calculated, and then the panoramic video and the laser point cloud are time synchronized according to the target time difference.

[0057] Exemplarily, the determining the position and posture of each frame image extracted from the panoramic video based on the time synchronization result of the panoramic video and the laser point cloud includes:

[0058] Determine the timestamp of each frame of image extracted from the panoramic video in the laser point cloud based on the target time difference and the timestamp of each frame of image extracted from the panoramic video in the panoramic video;

[0059] Based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud, the pose of each frame of image extracted from the panoramic video is determined.

[0060] Specifically, when determining the pose of each frame image extracted from the panoramic video according to the time synchronization result of the panoramic video and the laser point cloud, the timestamp of each frame image extracted from the panoramic video in the panoramic video can be determined first, and then the timestamp of each frame image extracted from the panoramic video in the laser point cloud can be determined according to the target time difference, and finally the pose of each frame image extracted from the panoramic video can be determined according to the timestamp of each frame image extracted from the panoramic video in the laser point cloud. That is, according to the target time difference, the timestamp of each frame image extracted from the panoramic video in the panoramic video is converted to the laser point cloud, and then the pose of each frame image extracted from the panoramic video is determined.

[0061] Exemplarily, determining the pose of each frame of image extracted from the panoramic video based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud includes:

[0062] The pose of each frame of image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame of image extracted from the panoramic video.

[0063] Specifically, when determining the pose of each frame image extracted from the panoramic video based on the timestamp of each frame image extracted from the panoramic video in the laser point cloud, the pose of the laser radar corresponding to the timestamp of each frame image extracted from the panoramic video in the laser point cloud can be determined first, and then the pose of each frame image extracted from the panoramic video can be determined based on the pose of the laser radar.

[0064] Exemplarily, determining the pose of each frame of image extracted from the panoramic video based on the pose of the laser radar corresponding to the timestamp of each frame of image extracted from the panoramic video in the laser point cloud includes:

[0065] The pose of each frame image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame image extracted from the panoramic video, and the transformation matrix from the laser radar coordinate system to the panoramic camera coordinate system.

[0066] Specifically, when determining the pose of each frame of image extracted from the panoramic video based on the pose of the lidar corresponding to the timestamp of each frame of image extracted from the panoramic video in the laser point cloud, the transformation matrix from the lidar coordinate system to the panoramic camera coordinate system can be determined first, and then the pose of the lidar can be transformed according to the transformation matrix from the lidar coordinate system to the panoramic camera coordinate system to obtain the pose of each frame of image extracted from the panoramic video.

[0067] Exemplarily, generating a digital elevation model of the target area based on the laser point cloud includes:

[0068] The laser point cloud is denoised, and a digital elevation model of the target area is generated based on the denoised laser point cloud.

[0069] Specifically, when generating a DEM of a target area based on a laser point cloud, the laser point cloud may be denoised first, for example, by denoising the laser point cloud using a two-dimensional gamma distribution or other denoising algorithms, and then the DEM of the target area may be generated based on the denoised laser point cloud.

[0070] Exemplarily, the method further includes:

[0071] After the digital orthophoto of the target area is generated, the target digital orthophoto is derived based on a preset accuracy.

[0072] Specifically, in order to save storage space, the DOM export accuracy may be set according to actual conditions, and then after the DOM of the target area is generated, the target DOM is exported according to the preset accuracy.

[0073] The technical solution of the present invention is better described below with reference to a specific embodiment:

[0074] Combination Figure 2 Come and see, Figure 2 This is a flow chart of an embodiment of an orthophoto generation process provided by the present invention, and the process specifically includes the following steps:

[0075] 1. Use a handheld laser scanner to obtain panoramic video and lidar data of the target area: Use an integrated panoramic camera and lidar equipment to slowly shoot along a predetermined path within the scope of field archaeology to ensure stable and accurate data collection of the study area.

[0076] (1) Instrument calibration: Find the same-name points between the panoramic image and the radar, and calculate the transformation rotation matrix from the radar coordinate system to the panoramic coordinate system based on the relationship between the same-name points.

[0077] (2) Design a collection route for the field archaeological area, requiring that the collected point cloud and panoramic data include all structures within the study area.

[0078] 2. Target scene DEM generation: Using the laser point cloud collected by the lidar equipment, use QGis and other open source software to generate a digital elevation model DEM within the scope of field archaeology.

[0079] (1) Point cloud preprocessing: remove noise points in the point cloud and retain only the point cloud in the study area.

[0080] (2) Use open source software to generate DEM within the scope of field archaeology.

[0081] 3. Time synchronization of panoramic video and laser point cloud: Time synchronization is completed through the IMU data recorded by the panoramic camera and the laser radar device during the data acquisition process. IMU data is a combination of information such as the acceleration of the device during movement. During the movement process, the acceleration of the panoramic camera and the laser point cloud should be the same at the same time.

[0082] (1) Read the IMU recorded value IMU_pano of the panoramic video and the IMU recorded value IMU_point of the lidar.

[0083] (2) Record the timestamps of the maximum values ​​of IMU_pano and IMU_point during the entire recording process.

[0084] (3) Obtain the time difference dt from the panoramic video to the radar. The timestamp of a frame of panoramic video plus dt is the radar timestamp of the panoramic image at the same moment.

[0085] 4. Panoramic image pose acquisition: Starting from the SLAM trajectory of the laser point cloud, the pose of any panoramic image is obtained through the calibration relationship.

[0086] (1) Panoramic video frame extraction: The frame extraction interval is pre-determined by the walking speed of the video shooter, and the panoramic image is extracted from the panoramic video at a certain frequency according to the frame extraction interval.

[0087] (2) Obtain the timestamp of each extracted panoramic image based on the timeline of the panoramic video.

[0088] (3) The panoramic image timestamp is added to the time interpolation dt to obtain the timestamp of the panoramic image in the radar time axis.

[0089] (4) Calculation of panoramic image pose: The rotation matrix of the specified radar frame is obtained according to the timestamp of the panoramic image in the radar time axis, and the transformation matrix between the radar coordinate system and the panoramic coordinate system is combined to solve the pose of the panoramic image.

[0090] 5. High-precision orthophoto generation: In the camera measurement tool, the panoramic image’s posture and DEM are used to generate a high-resolution DOM with geographic reference. This image not only accurately reflects the spatial geometric characteristics of the surface, but can also be combined with DEM to show the terrain changes at the archaeological site.

[0091] (1) Generate high-resolution DOM using photogrammetry tools.

[0092] (2) High-precision DOM consumes more storage space. You need to select the export precision based on the actual situation and downsample the DOM according to the specified precision to obtain the target DOM.

[0093] The present invention realizes the generation of high-precision orthophotos for field archaeology and speeds up the recording of archaeological sites.

[0094] The embodiment of the present invention also provides a device for generating orthophotos of field archaeological excavation test squares, Figure 3 Come and see, Figure 3 The structural diagram of an embodiment of an orthophoto generating device for a field archaeological excavation probe provided by the present invention is as follows. The orthophoto generating device 300 for a field archaeological excavation probe comprises:

[0095] An acquisition module 301 is used to acquire a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar;

[0096] A synchronization module 302 is used to generate a digital elevation model of the target area based on the laser point cloud, and perform time synchronization between the panoramic video and the laser point cloud;

[0097] A determination module 303 is used to extract frames from the panoramic video, and determine the pose of each frame of the image extracted from the panoramic video based on a time synchronization result between the panoramic video and the laser point cloud;

[0098] The generating module 304 is used to generate a digital orthophoto of the target area based on the digital elevation model and the position and posture of each frame of the image extracted from the panoramic video.

[0099] The specific implementation methods of each module of the device for generating orthophotos of field archaeological excavation trenches can be found in the description of the method for generating orthophotos of field archaeological excavation trenches mentioned above, and have similar beneficial effects, which will not be repeated here.

[0100] The embodiment of the present invention further provides an electronic device, Figure 4 Come and see, Figure 4 This is a structural diagram of an embodiment of an electronic device provided by the present invention. The electronic device 400 includes a processor 401, a memory 402, and a computer program stored in the memory 402 and executable on the processor 401. When the processor 401 executes the program, the orthophoto generation method of the field archaeological excavation probe as described above is implemented.

[0101] As a preferred embodiment, the electronic device 400 further includes a display 403 for displaying the orthophoto generation method of the field archaeological excavation pit executed by the processor 401 as described above.

[0102] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in the memory 402, and executed by the processor 401 to complete the present invention. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device 400. For example, the computer program may be divided into the acquisition module 301, the synchronization module 302, the determination module 303, and the generation module 304 in the above embodiment, and the specific functions of each module are as described above, and are not described one by one here.

[0103] The electronic device 400 may be a desktop computer, a notebook, a PDA or a smart phone with an adjustable camera module.

[0104] Among them, the processor 401 may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor 401 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0105] The memory 402 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electric erasable programmable read-only memory (EEPROM), etc. The memory 402 is used to store programs, and the processor 401 executes the program after receiving the execution instruction. The process definition method disclosed in any of the embodiments of the present invention may be applied to the processor 401 or implemented by the processor 401.

[0106] The display 403 may be an LCD display screen or an LED display screen, for example, a display screen on a mobile phone.

[0107] Understandably, Figure 4 The structure shown is only a schematic diagram of the structure of the electronic device 400. The electronic device 400 may also include Figure 4 More or fewer components as shown. Figure 4 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0108] The electronic device provided according to the above-mentioned embodiment of the present invention can be implemented with reference to the specific description of the method for generating orthophotos of a field archaeological excavation square as described above according to the present invention, and has similar beneficial effects as the method for generating orthophotos of a field archaeological excavation square as described above, which will not be repeated here.

[0109] An embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for generating orthophotos of a field archaeological excavation pit as described above is implemented.

[0110] Generally speaking, the computer instructions for implementing the method of the present invention can be carried by any combination of one or more computer-readable storage media. Non-transitory computer-readable storage media can include any computer-readable media except the signal itself that is temporarily propagating.

[0111] Computer-readable storage media may be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium that contains or stores a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0112] Computer program codes for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" or similar programming languages, in particular, Python suitable for neural network computing and platform frameworks based on TensorFlow, PyTorch, etc. may be used. The program code may be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0113] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0114] The present invention discloses a method and device for generating orthophotos of a field archaeological excavation probe. Firstly, a panoramic video and a laser point cloud of a target area are obtained to provide basic data for subsequent image processing. Then, a DEM of the target area is generated through the laser point cloud of the target area, so as to determine the terrain change of the target area. Then, the position and posture of each frame image extracted from the panoramic video are determined by time synchronization of the panoramic video and the laser point cloud, so as to determine the surface spatial geometric features of the target area. Finally, a DOM of the target area is generated according to the DEM and the position and posture of each frame image extracted from the panoramic video, so as to achieve the acquisition of all-round spatial data of the target area. While achieving the acquisition of all-round spatial data of the target area, the present invention ensures the measurement accuracy and improves the efficiency of data acquisition through a convenient image processing process.

[0115] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for generating orthophotos of field archaeological excavation test pits, characterized in that: include: Acquire a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar; Generating a digital elevation model of the target area based on the laser point cloud, and performing time synchronization between the panoramic video and the laser point cloud; Extract frames from the panoramic video, and determine the pose of each frame of the image extracted from the panoramic video based on a time synchronization result between the panoramic video and the laser point cloud; Generate a digital orthophoto of the target area based on the digital elevation model and the pose of each frame of the image extracted from the panoramic video; The step of performing time synchronization on the panoramic video and the laser point cloud comprises: Acquire first inertial measurement unit data corresponding to the panoramic video and second inertial measurement unit data corresponding to the laser point cloud; The panoramic video and the laser point cloud are time synchronized based on a target time difference, where the target time difference is a difference between a timestamp corresponding to a maximum value in the first inertial measurement unit data and a timestamp corresponding to a maximum value in the second inertial measurement unit data.

2. The method for generating orthophotos of field archaeological excavation probes according to claim 1, characterized in that: The step of determining the position and posture of each frame of the image extracted from the panoramic video based on the time synchronization result of the panoramic video and the laser point cloud comprises: Determine the timestamp of each frame of image extracted from the panoramic video in the laser point cloud based on the target time difference and the timestamp of each frame of image extracted from the panoramic video in the panoramic video; Based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud, the pose of each frame of image extracted from the panoramic video is determined.

3. The method for generating orthophotos of field archaeological excavation probes according to claim 2, characterized in that: The step of determining the position and posture of each frame of image extracted from the panoramic video based on the timestamp of each frame of image extracted from the panoramic video in the laser point cloud comprises: The pose of each frame of image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame of image extracted from the panoramic video.

4. The method for generating orthophotos of field archaeological excavation probes according to claim 3, characterized in that: The step of determining the pose of each frame of image extracted from the panoramic video based on the pose of the laser radar corresponding to the timestamp of each frame of image extracted from the panoramic video in the laser point cloud comprises: The pose of each frame image extracted from the panoramic video is determined based on the pose of the laser radar corresponding to the timestamp in the laser point cloud of each frame image extracted from the panoramic video, and the transformation matrix from the laser radar coordinate system to the panoramic camera coordinate system.

5. The method for generating orthophotos of field archaeological excavation test squares according to any one of claims 1 to 4, characterized in that: The step of generating a digital elevation model of the target area based on the laser point cloud comprises: The laser point cloud is denoised, and a digital elevation model of the target area is generated based on the denoised laser point cloud.

6. The method for generating orthophotos of field archaeological excavation test squares according to any one of claims 1 to 4, characterized in that: The method further comprises: After the digital orthophoto of the target area is generated, the target digital orthophoto is derived based on a preset accuracy.

7. A device for generating orthophotos of field archaeological excavation test pits, characterized in that: include: An acquisition module, used to acquire a panoramic video of a target area captured by a panoramic camera and a laser point cloud of the target area captured by a laser radar; A synchronization module, used to generate a digital elevation model of the target area based on the laser point cloud, and to perform time synchronization between the panoramic video and the laser point cloud; A determination module, configured to extract frames from the panoramic video, and determine the pose of each frame of the image extracted from the panoramic video based on a time synchronization result between the panoramic video and the laser point cloud; A generating module, used for generating a digital orthophoto of the target area based on the digital elevation model and the pose of each frame image extracted from the panoramic video; The step of performing time synchronization on the panoramic video and the laser point cloud comprises: Acquire first inertial measurement unit data corresponding to the panoramic video and second inertial measurement unit data corresponding to the laser point cloud; The panoramic video and the laser point cloud are time synchronized based on a target time difference, where the target time difference is a difference between a timestamp corresponding to a maximum value in the first inertial measurement unit data and a timestamp corresponding to a maximum value in the second inertial measurement unit data.

8. An electronic device, characterized in that: It includes a memory and a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the method for generating orthophotos of field archaeological excavation pits according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the method for generating orthophotos of a field archaeological excavation pit as described in any one of claims 1 to 6 is implemented.

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