Incomplete scanned image fitting method, device, terminal and storage medium

Abstract

The embodiment of the present invention discloses a method, device, terminal and storage medium for fitting an incomplete scanned image. The method comprises: obtaining image data; if the image data lacks the focal length parameter of the camera, obtaining the photographic scale of the image; inversely calculating the exterior orientation elements of the image data through absolute orientation; obtaining the flight altitude when the image was photographed through the exterior orientation elements; obtaining the focal length parameters after fitting based on the flight altitude and the photographic scale; and performing aerial triangulation on the fitted image data. The problem that incomplete scanned images cannot be used for aerial triangulation is solved, so that incomplete scanned images can also be used for aerial triangulation, thereby increasing the output rate.

Description

Technical Field

[0001] The present invention relates to the field of surveying and mapping, and in particular to a method, device, terminal and storage medium for fitting an incomplete scanned image. Background Art

[0002] In the aerial photogrammetry specification, when performing aerial triangulation on scanned images, the image's internal orientation must be completed first. This work requires the image's frame mark information and the focal length at the time of photography. After the image's internal orientation is completed, relative orientation and absolute orientation are performed. Therefore, the camera parameters determine whether the aerial triangulation project can be established correctly. For scanned images, the camera parameters affect the internal orientation and absolute orientation steps of the process, which plays a very important role in the development of aerial triangulation. Scanned image data may be missing due to storage media and time. Due to incomplete data, these images are difficult to produce normal photogrammetry. Summary of the invention

[0003] In view of this, the present invention provides a method for fitting an incomplete scanned image, the method comprising:

[0004] Acquire image data;

[0005] If the image data lacks the focal length parameter of the camera, obtaining the photographic scale of the image;

[0006] Reversely calculate the exterior orientation elements of the image data through absolute orientation;

[0007] Obtaining the flight altitude during image photography through the exterior orientation elements;

[0008] Based on the flight altitude and the photographic scale, obtaining a fitted focal length parameter;

[0009] The fitted image data is subjected to aerial triangulation.

[0010] Furthermore, the focal length calculation formula is:

[0011]

[0012] Wherein, m is the inverse of the photographic scale, f is the focal length of the camera, and H is the flight altitude.

[0013] Furthermore, it also includes:

[0014] Calculate the image size of a single pixel using the ground resolution of the image;

[0015] The image size is multiplied by the image scale to obtain the pixel size.

[0016] Furthermore, the aerial triangulation includes:

[0017] Determining whether the image data includes frame mark data;

[0018] If the image data does not contain the frame mark data, relative orientation and absolute orientation are performed in sequence;

[0019] If the image data includes the frame mark data, the frame mark distance is calculated according to the pixel size, and then the internal orientation, relative orientation and absolute orientation are performed in sequence.

[0020] Furthermore, after completing the aerial triangulation, the method further includes:

[0021] Performing an accuracy check on the measurement data, and if the accuracy does not meet the standard, performing a secondary fit on the focal length data, and then re-performing the aerial triangulation;

[0022] If the accuracy meets the requirement, the measurement data is output as aerial triangulation results.

[0023] Furthermore, the frame mark distance calculation formula is:

[0024] L = n*m;

[0025] Wherein, L is the frame mark distance, n is the pixel size, and m is the number of pixels between two frame marks in the image.

[0026] Furthermore, the present invention also provides a device for fitting an incomplete scanned image, comprising:

[0027] A data acquisition module, used to acquire image data; if the image data lacks the focal length parameter of the camera, then acquire the photographic scale of the image data;

[0028] A fitting module is used to calculate the exterior orientation elements of the image through absolute orientation; obtain the flight altitude when the image was taken through the exterior orientation elements; and obtain the focal length parameters after fitting based on the flight altitude and the photographic scale;

[0029] The measurement module is used to perform aerial triangulation on the fitted image data.

[0030] Furthermore, the measurement module includes:

[0031] A determination submodule, used to determine whether the image data contains frame mark data;

[0032] The orientation submodule is used to sequentially perform relative orientation and absolute orientation if the image data does not contain the frame mark data; if the image data contains the frame mark data, calculate the frame mark distance according to the pixel size, and then sequentially perform internal orientation, relative orientation and absolute orientation.

[0033] Furthermore, an embodiment of the present invention also provides a computer terminal, including a processor and a memory, wherein the memory stores a computer program, and when the computer program runs on the processor, it executes the incomplete scanned image fitting method described in any of the above embodiments.

[0034] Furthermore, an embodiment of the present invention also provides a readable storage medium storing a computer program, and when the computer program is run on a processor, the incomplete scanned image fitting method described in any of the above embodiments is executed.

[0035] The embodiment of the present application provides a method for fitting an incomplete scanned image, including: obtaining image data; if the image data lacks the focal length parameter of the camera, obtaining the photographic scale of the image; by absolute orientation, inversely calculating the exterior orientation elements of the image data; obtaining the altitude when the image was photographed by the exterior orientation elements; based on the altitude and the photographic scale, obtaining the fitted focal length parameters; performing aerial triangulation on the fitted image data. By fitting the camera parameters, the incomplete scanned image can be used for the orientation operation in the aerial triangulation, solving the problem that the incomplete scanned image cannot be used for the aerial triangulation work, so that the incomplete scanned image can also be used for aerial triangulation, increasing the output rate of the measurement results, and improving the work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope of protection of the present invention. In each of the drawings, similar components are numbered similarly.

[0037] Figure 1 A schematic diagram of a flow chart of a method for fitting an incomplete scanned image in an embodiment of the present application is shown;

[0038] Figure 2 A schematic diagram of a device for fitting an incomplete scanned image in an embodiment of the present application is shown;

[0039] Figure 3 A schematic diagram of a computer terminal in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0041] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0042] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present invention, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0043] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0044] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present invention belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present invention.

[0045] Next, the technical solution of the present application is explained with specific embodiments.

[0046] This embodiment provides a method for fitting an incomplete scanned image. Figure 1 As shown, when applied to aerial triangulation, the acquired image data lacks camera data.

[0047] Step S100, acquiring image data.

[0048] First, the captured image data is obtained, where the image data is the aerial photography image taken by the drone in the air. Normal photography data will include the focal length and frame mark of the camera. After completing the internal orientation using the focal length and frame mark data, the normal aerial triangulation process begins. However, due to storage or time reasons, this part of the data will be missing from the final stored data.

[0049] In step S200, if the image data lacks the focal length parameter of the camera, the photographic scale of the image is obtained.

[0050] When the image data lacks focal length parameters, the internal orientation operation cannot be performed, so the focal length parameters need to be fitted. Among them, for image data, the image scale is the easiest parameter to obtain. This parameter can be directly obtained through the flight plan, scanned images or other technical data of aerial photography.

[0051] Step S300: inversely calculate the exterior orientation elements of the image data through absolute orientation;

[0052] After absolute orientation, the external orientation elements can be calculated inversely, that is, the spatial position of the photographic beam at the moment of photography. This spatial position includes the three-dimensional coordinates of the photographic center in a certain spatial rectangular coordinate system and the heading inclination, lateral inclination and film rotation angle when one of the axes is the main axis.

[0053] Step S400 obtains the flight altitude when the image is taken through the exterior orientation elements.

[0054] Through these data of exterior orientation elements, the altitude at which the image was taken can be directly calculated, that is, the height at which the camera was located when taking the image.

[0055] Step S500: obtaining a fitted focal length parameter based on the flight altitude and the photographic scale;

[0056] Knowing the flight altitude and scale, the focal length parameters of the camera can be calculated. The scale of this embodiment is 1:m, and the calculation formula of the focal length is as follows:

[0057]

[0058] Wherein, m is the inverse of the photographic scale, f is the focal length of the camera, and H is the flight altitude.

[0059] In addition to the focal length f, the pixel size of the image can also be calculated. First of all, the ground resolution of the image is also an easily obtained and non-missing data. According to the ground resolution, the image size of a single pixel in the image can be obtained. The image size is the specific size of the pixel in the image, such as 6.5 microns.

[0060] After obtaining the image size of a pixel, the specific pixel size and the actual distance represented by a pixel can be calculated through the image size and the scale.

[0061] Step S600 performs aerial triangulation on the fitted image data.

[0062] After obtaining the focal length parameters, aerial triangulation can be performed. Aerial triangulation includes three orientation operations: internal orientation, relative orientation, and absolute orientation. In order to calculate the position data of the control point, in addition to the above-mentioned camera focal length, the camera's frame mark data is also required. The frame mark is the frame mark located in the image after the external image is taken. The frame mark data is required for internal orientation, so the distance between the frame marks needs to be calculated. Because the frame marks are displayed on the image, the number of pixels between the frame marks can be directly obtained, and then the actual distance between the frame marks is obtained by multiplying the number of pixels and the pixel size to perform the internal orientation operation. The frame mark distance calculation formula is:

[0063] L = n*m;

[0064] Wherein, L is the frame mark distance, n is the pixel size, and m is the number of pixels between two frame marks in the image.

[0065] When processing images, the frame markers may be cropped, resulting in missing frame marker data.

[0066] Therefore, in the absence of frame mark data, the internal orientation step will be skipped and relative orientation and absolute orientation will be performed directly.

[0067] After absolute orientation, the measurement data is checked for accuracy. If the accuracy does not meet the standard, the focal length data is subjected to secondary fitting, and then the aerial triangulation is performed again.

[0068] For example, after the camera parameters are fitted, the deformed area at the edge of the image is involved in the camera parameter fitting process, resulting in systematic errors in the fitted parameters. At the same time, early aerial photography cameras basically have camera principal point offsets, which will affect the accuracy of relative orientation. After the aerial triangulation work is completed through internal orientation, the deformed area at the edge of the image is removed, and the camera parameters are fitted again, which is closer to the mathematical basis of aerial triangulation.

[0069] If the accuracy meets the requirement, the measurement data is output as aerial triangulation results.

[0070] The present application also provides a device for fitting an incomplete scanned image. Figure 2 Shown include:

[0071] The data acquisition module 10 is used to acquire image data; if the image data lacks the focal length parameter of the camera, the photographic scale of the image data is acquired;

[0072] The fitting module 20 is used to calculate the exterior orientation elements of the image through absolute orientation; obtain the flight altitude when the image was taken through the exterior orientation elements; and obtain the focal length parameters after fitting based on the flight altitude and the photography scale;

[0073] The measurement module 30 is used to perform aerial triangulation on the fitted image data.

[0074] A determination submodule 40 is used to determine whether the image data contains frame mark data;

[0075] The orientation submodule 50 is used to sequentially perform relative orientation and absolute orientation if the image data does not contain the frame mark data; if the image data contains the frame mark data, calculate the frame mark distance according to the pixel size, and then sequentially perform internal orientation, relative orientation and absolute orientation.

[0076] Furthermore, the embodiment of the present invention also provides a computer terminal 60, such as Figure 3 As shown, it includes a processor 61 and a memory 62, and the memory 62 stores a computer program. When the computer program runs on the processor 61, it executes the incomplete scan image fitting method described in any of the above embodiments.

[0077] Furthermore, an embodiment of the present invention also provides a readable storage medium storing a computer program, and when the computer program is run on a processor, the incomplete scanned image fitting method described in any of the above embodiments is executed.

[0078] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow chart, and the combination of boxes in the structure diagram and / or the flow chart, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0079] In addition, the functional modules or units in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0080] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer terminal (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0081] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for fitting an incomplete scanned image, characterized in that: The method includes: Acquire image data; If the image data lacks the focal length parameter of the camera, obtaining the photographic scale of the image; Reversely calculate the exterior orientation elements of the image data through absolute orientation; Obtaining the flight altitude during image photography through the exterior orientation elements; Based on the flight altitude and the photographic scale, obtaining a fitted focal length parameter; The fitted image data is subjected to aerial triangulation.

2. The incomplete scanned image fitting method according to claim 1, characterized in that: The focal length calculation formula is: Wherein, m is the inverse of the photographic scale, f is the focal length of the camera, and H is the flight altitude.

3. The incomplete scanned image fitting method according to claim 1, characterized in that: Also includes: Calculate the image size of a single pixel using the ground resolution of the image; The image size is multiplied by the photographic scale to obtain the pixel size.

4. The incomplete scanned image fitting method according to claim 3, characterized in that: The aerial triangulation includes: Determining whether the image data includes frame mark data; If the image data does not contain the frame mark data, relative orientation and absolute orientation are performed in sequence; If the image data includes the frame mark data, the frame mark distance is calculated according to the pixel size, and then the internal orientation, relative orientation and absolute orientation are performed in sequence.

5. The incomplete scanned image fitting method according to claim 4, characterized in that: After completing the aerial triangulation, the following steps are also included: Performing an accuracy check on the measurement data, and if the accuracy does not meet the standard, performing a secondary fit on the focal length parameter, and then re-performing the aerial triangulation; If the accuracy meets the requirement, the measurement data is output as aerial triangulation results.

6. The incomplete scanned image fitting method according to claim 4, characterized in that: The frame mark distance calculation formula is: L = n*m; Wherein, L is the frame mark distance, n is the pixel size, and m is the number of pixels between two frame marks in the image.

7. A device for fitting incomplete scanned images, characterized in that: include: A data acquisition module, used to acquire image data; if the image data lacks the focal length parameter of the camera, then acquire the photographic scale of the image data; A fitting module is used to calculate the exterior orientation elements of the image through absolute orientation; obtain the flight altitude when the image was taken through the exterior orientation elements; and obtain the focal length parameters after fitting based on the flight altitude and the photographic scale; The measurement module is used to perform aerial triangulation on the fitted image data.

8. The incomplete scanned image fitting device according to claim 7, characterized in that: The measurement module comprises: A determination submodule, used to determine whether the image data contains frame mark data; The orientation submodule is used to sequentially perform relative orientation and absolute orientation if the image data does not contain the frame mark data; if the image data contains the frame mark data, calculate the frame mark distance according to the pixel size, and then sequentially perform internal orientation, relative orientation and absolute orientation.

9. A computer terminal, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program, and when the computer program is run on the processor, the incomplete scan image fitting method according to any one of claims 1 to 6 is executed.

10. A readable storage medium, characterized in that: It stores a computer program, which, when running on a processor, executes the incomplete scan image fitting method described in any one of claims 1 to 6.

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