Oblique photogrammetry aerial survey data processing method and storage medium

Abstract

The application belongs to the technical field of data processing, and discloses a tilt photography aerial survey data processing method and a storage medium. The processing method comprises the following steps: acquiring tilt photography data, performing flight division on the tilt photography image according to the pos information and the photographing interval; storing the tilt photography data corresponding to the flight; acquiring the unmanned aerial vehicle type information, updating the pos information; writing the updated pos information into the corresponding tilt photography image; acquiring the camera information, and writing the camera distortion parameter information corresponding to the camera information into the tilt photography image; acquiring the export flight information, and generating a file used for import into a three-dimensional modeling software for processing based on the storage position of the tilt photography image, the corresponding pos information and the camera distortion parameter information. The tilt photography aerial survey data processing method provided by the application can generate tilt photography data meeting different three-dimensional modeling software and adapt to different application scenarios.

Description

Technical Field

[0001] This invention belongs to the field of data processing technology, specifically relating to a method for processing oblique photogrammetric aerial survey data and a storage medium. Background Technology

[0002] Oblique photogrammetry is a technology that has been developed in the international surveying and mapping field in recent years. It has overturned the previous limitation that orthophotos could only be taken from a vertical angle. By mounting a camera with multiple lenses on the same flight platform, it can simultaneously collect images from five different angles, including one vertical angle and four oblique angles. This allows users to observe ground features from multiple angles, reflect the true situation of the ground features, and bring users into a real and intuitive world that conforms to human vision.

[0003] 3D models obtained using oblique photogrammetry can intuitively reflect ground features and texture information, greatly promoting the development of the surveying and mapping industry and providing fundamental data for 3D digital city applications. In the process of realizing this invention, the inventors discovered that existing technologies for processing oblique photogrammetry data still have some problems:

[0004] 1. To ensure the integrity and accuracy of the subsequent 3D modeling, the target survey area is expanded based on the target survey area and the survey parameters during oblique photogrammetry aerial surveys. This results in the oblique photogrammetry camera collecting redundant data unrelated to the target survey area during the aerial survey process. The large amount of data processing leads to a long processing time in the subsequent 3D modeling process, resulting in a waste of computer resources and labor costs. If the redundant images are weak texture images, it will also have a negative impact on the modeling and affect the modeling accuracy.

[0005] 2. During aerial surveying operations, multiple survey areas may be photographed simultaneously, resulting in discontinuous flight areas. If oblique photogrammetry data is incorrectly processed together, it can lead to modeling errors. There are various types of 3D modeling software, each with different data format requirements. Therefore, oblique photogrammetry data needs to be processed before 3D modeling. Currently, this relies on manual operation by office staff, which is cumbersome, time-consuming, and subject to the subjective judgment and carelessness of the office staff, resulting in a high error rate.

[0006] 3. Aerial surveying work is labor-intensive. Under high-intensity operation, oblique photogrammetry cameras may miss some images, which will lead to a discrepancy between the number of photos taken and the number of points of interest (POS). On the one hand, this is often easily overlooked by the office staff, resulting in mismatch between photos and POS, affecting the accuracy of the 3D model. On the other hand, the large amount of oblique photogrammetry data requires a lot of effort to find the missed points, increasing manpower costs and affecting the project schedule.

[0007] 4. The impact of camera distortion information on the accuracy of the 3D model was ignored. Summary of the Invention

[0008] The present invention aims to at least partially solve the aforementioned technical problems. Therefore, the objective of the present invention is to provide a method for processing oblique photogrammetric aerial survey data and a storage medium.

[0009] The technical solution adopted in this invention is as follows:

[0010] A method for processing oblique photogrammetric aerial survey data includes the following steps:

[0011] Acquire oblique photogrammetry data, and classify the oblique photogrammetry images in the oblique photogrammetry data into frames based on POS information and shooting interval; store the oblique photogrammetry data of the corresponding frames.

[0012] Obtain drone type information, update POS information using the offset information corresponding to drone type information; write the updated POS information into the corresponding oblique photogrammetric image.

[0013] Acquire camera information and write the corresponding camera distortion parameter information into the oblique photography image;

[0014] The system retrieves export flight information and generates files for importing into 3D modeling software based on the storage location of the oblique photogrammetric images, the corresponding POS information, and camera distortion parameters.

[0015] Preferably, the oblique photogrammetry aerial survey data processing method further includes the step of comparing the number of images and the number of positions for each viewpoint of the oblique photogrammetry image, and correcting any inconsistencies to make them consistent.

[0016] If the number of pos is greater than the number of images, then based on the shooting interval, determine the location of the missing image and remove the pos points corresponding to the missing image locations in the pos information: compare the shooting time interval between two adjacent photos in turn. If the shooting time interval between two adjacent photos is greater than the set value, check whether there is any redundant pos information between the pos points corresponding to these two photos. If so, delete it; if no shooting time interval between two adjacent photos is found to be greater than the shooting interval after the comparison, then based on the pos point generation interval, delete the pos points whose pos point generation interval is less than the set value.

[0017] If the number of images is greater than the number of pos, then based on the shooting interval, one of the images whose shooting interval is less than the set value will be removed; if none of them exist, then one of the pos points whose pos point generation interval is greater than the set value will be copied between the two pos points.

[0018] Preferably, the method for processing oblique photogrammetric aerial survey data further includes the step of: filtering oblique photogrammetric images and POS information according to the survey area range file and removing redundant data.

[0019] Based on the boundary line range of the target survey area, compare the POS information corresponding to the downward view image and remove the downward view image corresponding to the POS information located outside the boundary line; based on the boundary line range of the extended survey area, compare the POS information corresponding to the forward view image, backward view image, left view image, and right view image respectively, remove the right view image located outside the left boundary line in the boundary line range, remove the left view image located outside the right boundary line in the boundary line range, remove the backward view image located outside the front boundary line in the outer boundary range, and remove the forward view image located within the rear boundary line in the outer boundary range.

[0020] Preferably, the pos information includes latitude and longitude information, generation time, and corresponding viewpoint.

[0021] Preferably, the oblique photography images include front-view images, rear-view images, left-view images, right-view images, and downward-view images, and the oblique photography data includes the corresponding shooting time of the oblique photography images.

[0022] Preferably, the drone type information and camera information are both stored in the oblique photography camera; the camera information includes the camera type and camera number.

[0023] Preferably, the exported flight information is set according to the divided flights and processing requirements.

[0024] A storage medium storing computer-executable code, which, when executed, implements the above-described oblique photogrammetry aerial data processing method.

[0025] The beneficial effects of this invention are as follows:

[0026] The oblique photogrammetry aerial survey data processing method provided by this invention can generate oblique photogrammetry data that meets the requirements of different 3D modeling software and is suitable for different application scenarios. It also facilitates the management and processing of oblique photogrammetry data, avoids the impact of confusion in the survey area on the modeling progress during processing, and avoids the impact of data mismatch on the modeling accuracy. At the same time, it takes into account the impact of distortion information on 3D modeling, which can improve the accuracy of subsequent 3D modeling. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the oblique photogrammetry aerial survey data processing method of the present invention. Detailed Implementation

[0028] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] It should be understood that, and also noted, in the embodiments, the functions / actions may appear in a different order than those shown in the figures. For example, depending on the functions / actions involved, they may actually be performed substantially concurrently, or sometimes the two figures shown consecutively may be performed in reverse order.

[0030] like Figure 1 As shown, an oblique photogrammetry aerial survey data processing method according to this embodiment specifically includes the following steps:

[0031] Oblique photogrammetry data is acquired. Based on the position information and shooting interval in the oblique photogrammetry data, the oblique photogrammetry images in the data are divided into flights, so that one flight corresponds to one set of position information, and the oblique photogrammetry data of the corresponding flight is stored. Since battery replacement is required between flights, the shooting interval between the last photo of one flight and the first photo of the next flight is long, and this interval is used as the basis for flight division.

[0032] The POS information includes latitude and longitude, generation time, and corresponding viewpoint. The oblique photogrammetry images include front-view, rear-view, left-view, right-view, and downward-view images, and the oblique photogrammetry data includes the corresponding shooting time of the oblique photogrammetry images.

[0033] Obtain the flight information to be processed, which is set by the user based on the divided flights and processing requirements; proceed with subsequent steps based on the flight information to save data processing time and improve efficiency.

[0034] The drone type information is acquired, the position information is updated using the offset information corresponding to the drone type information, and the updated position information is written to the corresponding oblique photogrammetry image. The drone type information is stored in the oblique photogrammetry camera.

[0035] The camera information is acquired, and the corresponding camera distortion parameters are written into the oblique photogrammetry image. This camera information includes the camera type and camera ID, and is stored in the oblique photogrammetry camera. At this point, the processed oblique photogrammetry image can be imported into DJI Terra for modeling.

[0036] Based on the survey area file, oblique photogrammetry images and POS information are filtered to remove redundant data. Removing redundant data reduces the amount of data processing, improves the efficiency of subsequent data processing, avoids the waste of computer resources and manpower, and reduces the impact of invalid data on 3D modeling.

[0037] Specifically, based on the boundary line range of the target survey area, the POS information corresponding to the downward view image is compared, and the downward view image corresponding to the POS information located outside the boundary line is eliminated; based on the boundary line range of the extended survey area, the POS information corresponding to the forward view image, backward view image, left view image, and right view image are compared, and the right view image located outside the left boundary line within the boundary line range is eliminated, the left view image located outside the right boundary line within the boundary line range is eliminated, the backward view image located outside the front boundary line within the outer boundary range is eliminated, and the forward view image located within the rear boundary line within the outer boundary range is eliminated.

[0038] The system retrieves the exported flight information. Based on this information, and using the storage location of the oblique photogrammetric images, the corresponding position information, and camera distortion parameters, it generates files for importing into 3D modeling software for processing. For example, it produces block files for quick import into ContextCapture (CC) for processing. The exported flight information is set by the user according to the allocated flight segments and processing requirements.

[0039] The above-mentioned method for processing oblique photogrammetry aerial survey data also includes the following steps: comparing the number of images and the number of positions (pos) for each angle of the oblique photogrammetry image to determine whether there are any missing images or missing positions; if there is a discrepancy between the number of images and the number of positions, it is corrected to be consistent, and a prompt message is issued to remind the office staff to pay attention.

[0040] Specifically, if the number of POS points exceeds the number of images, there is a missing image or multiple POS information. Based on the shooting interval, the location of the missing image is determined, and the POS points corresponding to the missing image locations in the POS information are removed. The shooting interval is uniform and is calculated based on the overlap rate set by the customer and the camera parameters. The shooting time interval between two adjacent photos is compared sequentially. If the shooting time interval between two adjacent photos is greater than the set value, it is checked whether there is any redundant POS information between the corresponding POS points of these two photos. If so, it is deleted. If no shooting time interval between two adjacent photos is found to be greater than the shooting interval after the comparison, the POS points with a POS point generation interval less than the set value are deleted based on the POS point generation interval.

[0041] If the number of images is greater than the number of pos, there will be missing points or multiple photos. Based on the shooting interval, one of the images whose shooting time interval is less than the set value will be removed. If no image is removed, one of the pos points whose pos point generation interval is greater than the set value will be copied between the two pos points.

[0042] This embodiment also provides a storage medium storing computer-executable code, which, when executed, implements the aforementioned oblique photogrammetry aerial data processing method. The storage medium includes flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic storage, magnetic disk, optical disk, etc.

[0043] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A method for processing oblique photogrammetric aerial survey data, characterized in that, Includes the following steps: Oblique photogrammetry data is acquired. Based on the POS information and shooting interval, the oblique photogrammetry images in the oblique photogrammetry data are divided into flights. The shooting interval between the last photo of a flight and the first photo of the next flight is used as the basis for flight division. The oblique photogrammetry data of the corresponding flights is stored. Obtain the flight information to be processed, which is set by the user based on the assigned flights and processing requirements; proceed with subsequent steps based on the flight information to be processed. Obtain drone type information, update POS information using the offset information corresponding to drone type information; write the updated POS information into the corresponding oblique photogrammetric image. Acquire camera information and write the corresponding camera distortion parameter information into the oblique photography image; Compare the number of images and the number of positions (pos) for each viewpoint in the oblique photography. If there is an inconsistency, correct it to be consistent. If the number of pos is greater than the number of images, determine the missing image position based on the shooting interval and remove the pos points corresponding to the missing image positions in the pos information. The shooting interval is a value calculated based on the overlap rate and camera parameters set by the customer. Compare the shooting time interval between two adjacent photos. If the shooting time interval between two adjacent photos is greater than the set value, check if there is any redundant pos information between the pos points corresponding to these two photos. If so, delete it. If no shooting time interval between two adjacent photos is found to be greater than the shooting interval after the comparison, delete pos points whose pos point generation interval is less than the set value based on the pos point generation interval. If the number of images is greater than the number of pos, then based on the shooting interval, one of the images whose shooting interval is less than the set value is removed; if none of them exist, then one of the pos points whose pos point generation interval is greater than the set value is copied between the two pos points. Based on the survey area range file, oblique photogrammetric images and POS information are filtered to remove redundant data; based on the boundary line range of the target survey area, the POS information corresponding to the downward view image is compared, and downward view images with POS information located outside the boundary line are removed; based on the boundary line range of the extended survey area, the POS information corresponding to the forward view image, backward view image, left view image, and right view image are compared, and right view images located outside the left boundary line within the boundary line range are removed, left view images located outside the right boundary line within the boundary line range are removed, backward view images located outside the forward boundary line within the outer boundary range are removed, and forward view images located within the backward boundary line within the outer boundary range are removed. The system retrieves export flight information and generates files for importing into 3D modeling software based on the storage location of the oblique photogrammetric images, the corresponding POS information, and camera distortion parameters.

2. The method for processing oblique photogrammetric aerial survey data according to claim 1, characterized in that: The pos information includes latitude and longitude information, generation time, and corresponding viewpoint.

3. The method for processing oblique photogrammetric aerial survey data according to claim 1, characterized in that: The oblique photography images include front-view images, rear-view images, left-view images, right-view images, and downward-view images, and the oblique photography data includes the corresponding shooting time of the oblique photography images.

4. The method for processing oblique photogrammetric aerial survey data according to claim 1, characterized in that: The drone type information and camera information are both stored in the oblique photography camera; the camera information includes the camera type and camera number.

5. The method for processing oblique photogrammetric aerial survey data according to claim 1, characterized in that: The exported flight information is set according to the divided flights and processing requirements.

6. A storage medium, characterized in that, It stores computer-executable code, which, when executed, implements the oblique photogrammetry aerial survey data processing method as described in any one of claims 1-5.

Images