A multi-angle photogrammetry method and system

Abstract

This invention discloses a multi-angle photogrammetry method and system. The method includes: acquiring photographic data and actual reference point data; obtaining reference point photographic data and measurement point photographic data based on the photographic data; sending the reference point photographic data and actual reference point data to a preset calculation model to obtain a set of photographic position poses; sending any two data points from the photographic position poses set and the measurement point photographic data to the preset calculation model to obtain a set of coordinates for all measurement points; extracting a subset of coordinates for the same measurement point from all the coordinate sets, and calculating the average distance between the coordinates in the subset to obtain the average distance between the coordinates of the same measurement point; extracting the minimum value among the average distances between the coordinates in the subset, and setting the coordinates corresponding to the minimum value as the final coordinates of the measurement point. This invention improves the accuracy of photogrammetry.

Description

Technical Field

[0001] This invention relates to the field of photogrammetry, and more specifically, to a multi-angle photogrammetry method and system. Background Technology

[0002] Currently, with the advancement of science and technology and the increasing demand for measurement, areas or objects that cannot be measured in person can be obtained through photogrammetry to determine their dimensions. Existing photogrammetry methods include terrestrial photogrammetry, aerial photogrammetry, and space photogrammetry. However, photogrammetry is subject to photographic errors or environmental errors caused by the real-world environment, which can interfere with the accuracy of photogrammetry.

[0003] Therefore, existing technologies have shortcomings and urgently need improvement. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a multi-angle photogrammetry method and system that can more effectively reduce photogrammetry errors.

[0005] The first aspect of this invention provides a multi-angle photogrammetry method, comprising:

[0006] Acquire photographic data and actual data information of reference points;

[0007] Based on the photographic data information, reference point photographic data and measurement point photographic data information are obtained;

[0008] The reference point photographic data and the actual reference point data are sent to the preset calculation model to obtain the photographic position pose set information;

[0009] Send any two data points from the photographic position pose set and the photographic data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points;

[0010] Extract the coordinate subset of the same measurement point from the coordinate set of all measurement points, and calculate the average distance between the coordinates of the same measurement point subset to obtain the average distance between the coordinates of the same measurement point subset.

[0011] Extract the minimum value of the average distance between coordinates in the same subset of measurement points, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point.

[0012] This plan also includes:

[0013] Obtain information about the object to be measured;

[0014] Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained;

[0015] Set the corners or endpoints of the object to be measured as measurement points.

[0016] In this solution, the step of sending the reference point photographic data and the actual reference point data to a preset calculation model to obtain the photographic position pose set information is specifically as follows:

[0017] Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained;

[0018] Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained;

[0019] The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position pose set {P1, P2, ..., P}. m},in

[0020] The calculation formula (1) for obtaining the shooting position pose in the preset calculation model is:

[0021]

[0022] The (x) N y N ) represents the image plane coordinates of the corresponding reference point in the photographic image with the principal point as the origin; f represents the principal distance of the interior orientation element; X S Y S Z S These represent the coordinates of the shooting position and pose in the ground coordinate system; X N Y N and Z N (N = 1, 2, ..., M, and N ≥ 3), representing the coordinates of the reference points in the ground coordinate system, where N represents the reference point number; a i b i c i (i = 1, 2, 3) are the nine direction cosines composed of the three exterior azimuth elements of the camera.

[0023] In this scheme, the step of sending any two data points from the photographic position pose set and the photographic data of the measurement points to a preset calculation model to obtain the coordinate set information of all measurement points is specifically as follows:

[0024] Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained;

[0025] Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained;

[0026] Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point;

[0027] Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points {A}. n-j}, where A n This indicates the measurement point labeled n, and j indicates the number of coordinate points of the measurement point labeled n;

[0028] The calculation formula (2) for obtaining the coordinates of the measurement point in the ground coordinate system from the preset calculation model is as follows:

[0029]

[0030] The (x) A y A (X) represents the image plane coordinates of measurement point A in the photographic image, with the principal point as the origin; A Y A Z A () represents the coordinates of measurement point A in the ground coordinate system. The pose coordinates of the corresponding shooting position.

[0031] In this scheme, the average distance between the coordinates of the same measurement point subset is calculated, specifically as follows:

[0032] Connect the coordinates of the same measurement point in pairs and calculate the distance between them;

[0033] The average distance d between the coordinates of the same measurement point subset and other coordinates is calculated by summing the distances and taking the mean value. The formula is as follows:

[0034]

[0035] Where μ∈j, This represents the average distance between the μ-th coordinate point among the measurement points labeled n. This represents the coordinates of the μ-th coordinate point among the measurement points labeled n.

[0036] This plan also includes:

[0037] Determine whether the average distance between coordinates in the same subset of measurement points is greater than a preset average distance threshold. If yes, the average distance is set to unqualified; otherwise, the average distance is qualified.

[0038] Arrange the average distance values ​​of the non-compliant points in descending order to obtain the maximum average distance of the non-compliant points;

[0039] The coordinates corresponding to the maximum average distance of the unqualified points are deleted, and the average distance of the coordinates in the same subset of measurement points is recalculated.

[0040] This plan also includes;

[0041] Obtain the number of qualified coordinates in the same subset of coordinates of a measurement point;

[0042] Determine whether the number of qualified coordinates in the same subset of coordinates of the same measurement point is greater than a preset threshold. If not, increase the measurement angle for that measurement point; otherwise, no increase is required.

[0043] A second aspect of the present invention provides a multi-angle photogrammetry system, including a memory and a processor. The memory stores a multi-angle photogrammetry method program, which, when executed by the processor, performs the following steps:

[0044] Acquire photographic data and actual data information of reference points;

[0045] Based on the photographic data information, reference point photographic data and measurement point photographic data information are obtained;

[0046] The reference point photographic data and the actual reference point data are sent to the preset calculation model to obtain the photographic position pose set information;

[0047] Send any two data points from the photographic position pose set and the photographic data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points;

[0048] Extract the coordinate subset of the same measurement point from the coordinate set of all measurement points, and calculate the average distance between the coordinates of the same measurement point subset to obtain the average distance between the coordinates of the same measurement point subset.

[0049] Extract the minimum value of the average distance between coordinates in the same subset of measurement points, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point.

[0050] This plan also includes:

[0051] Obtain information about the object to be measured;

[0052] Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained;

[0053] Set the corners or endpoints of the object to be measured as measurement points.

[0054] In this solution, the step of sending the reference point photographic data and the actual reference point data to a preset calculation model to obtain the photographic position pose set information is specifically as follows:

[0055] Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained;

[0056] Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained;

[0057] The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position pose set {P1, P2, ..., P}. m},in

[0058] The calculation formula (1) for obtaining the shooting position pose in the preset calculation model is:

[0059]

[0060] The (x) N y N ) represents the image plane coordinates of the corresponding reference point in the photographic image with the principal point as the origin; f represents the principal distance of the interior orientation element; X S Y S Z S These represent the coordinates of the shooting position and pose in the ground coordinate system; X N Y N and Z N (N = 1, 2, ..., M, and N ≥ 3), representing the coordinates of the reference points in the ground coordinate system, where N represents the reference point number; a i b i c i (i = 1, 2, 3) are the nine direction cosines composed of the three exterior azimuth elements of the camera.

[0061] In this scheme, the step of sending any two data points from the photographic position pose set and the photographic data of the measurement points to a preset calculation model to obtain the coordinate set information of all measurement points is specifically as follows:

[0062] Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained;

[0063] Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained;

[0064] Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point;

[0065] Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points {A}. n-j}, where A n This indicates the measurement point labeled n, and j indicates the number of coordinate points of the measurement point labeled n;

[0066] The calculation formula (2) for obtaining the coordinates of the measurement point in the ground coordinate system from the preset calculation model is as follows:

[0067]

[0068] The (x) A y A (X) represents the image plane coordinates of measurement point A in the photographic image, with the principal point as the origin; A Y A Z A () represents the coordinates of measurement point A in the ground coordinate system. The pose coordinates of the corresponding shooting position.

[0069] In this scheme, the average distance between the coordinates of the same measurement point subset is calculated, specifically as follows:

[0070] Connect the coordinates of the same measurement point in pairs and calculate the distance between them;

[0071] The average distance d between the coordinates of the same measurement point subset and other coordinates is calculated by summing the distances and taking the mean value. The formula is as follows:

[0072]

[0073] Where μ∈j, This represents the average distance between the μ-th coordinate point among the measurement points labeled n. This represents the coordinates of the μ-th coordinate point among the measurement points labeled n.

[0074] This plan also includes:

[0075] Determine whether the average distance between coordinates in the same subset of measurement points is greater than a preset average distance threshold. If yes, the average distance is set to unqualified; otherwise, the average distance is qualified.

[0076] Arrange the average distance values ​​of the non-compliant points in descending order to obtain the maximum average distance of the non-compliant points;

[0077] The coordinates corresponding to the maximum average distance of the unqualified points are deleted, and the average distance of the coordinates in the same subset of measurement points is recalculated.

[0078] This plan also includes;

[0079] Obtain the number of qualified coordinates in the same subset of coordinates of a measurement point;

[0080] Determine whether the number of qualified coordinates in the same subset of coordinates of the same measurement point is greater than a preset threshold. If not, increase the measurement angle for that measurement point; otherwise, no increase is required.

[0081] This invention discloses a multi-angle photogrammetry method and system, which refines photogrammetry data by using the average distance value of coordinate points, thereby improving the accuracy of photogrammetry. Attached Figure Description

[0082] Figure 1 A flowchart of a multi-angle photogrammetry method according to the present invention is shown;

[0083] Figure 2 A schematic diagram of collinearity constraints is shown;

[0084] Figure 3 A schematic diagram illustrating the calculation of the camera position and pose is shown.

[0085] Figure 4 A schematic diagram of the calculation of the coordinates of the measurement point is shown;

[0086] Figure 5 A block diagram of a multi-angle photogrammetry system according to the present invention is shown. Detailed Implementation

[0087] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0088] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0089] Figure 1 A flowchart of a multi-angle photogrammetry method according to the present invention is shown.

[0090] like Figure 1 As shown, this invention discloses a multi-angle photogrammetry method, comprising:

[0091] S102, acquire photographic data and actual data information of reference points;

[0092] S104, Based on the photographic data information, obtain the reference point photographic data and the measurement point photographic data information;

[0093] S106, send the reference point photographic data and the actual reference point data to the preset calculation model to obtain the photographic position pose set information;

[0094] S108: Send any two data points from the photography position pose set and the photography data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points;

[0095] S110, extract the subset of coordinates of the same measurement point from the set of coordinates of all measurement points, and calculate the average distance between the coordinates of the same subset of coordinates to obtain the average distance between the coordinates of the same subset of coordinates.

[0096] S112, extract the minimum value of the average distance between coordinates in the same subset of measurement points, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point.

[0097] It should be noted that the preset calculation model includes the collinearity equation for photogrammetry. Based on the collinearity constraint of photography, the camera center (light point), image point (measurement point or reference point in the photographic image), and object point (measurement point or reference point) are on the same straight line. Based on multi-angle photographic data and actual reference point data, the collinearity equation is used to obtain the coordinate set of all measurement points. This coordinate set contains multiple photogrammetric data points for the same measurement point. Then, the minimum average distance among the multiple photogrammetric data points for the same measurement point is determined by calculating the average distance. The coordinates corresponding to the minimum average distance are set as the final coordinates of that measurement point.

[0098] According to an embodiment of the present invention, it further includes:

[0099] Obtain information about the object to be measured;

[0100] Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained;

[0101] Set the corners or endpoints of the object to be measured as measurement points.

[0102] It should be noted that measurement is achieved by extracting the corner points or endpoints of the object to be measured, thus reducing the workload of photogrammetry. For example, if the distance between two points is to be measured, the two endpoints of the distance are set as measurement points.

[0103] refer to Figure 3 , Figure 3 A schematic diagram of photographic position and pose calculation is shown. According to an embodiment of the present invention, the step of sending the photographic data of the reference point and the actual data of the reference point to a preset calculation model to obtain the photographic position and pose set information specifically involves:

[0104] Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained;

[0105] Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained;

[0106] The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position pose set {P1, P2, ..., P}. m},in

[0107] The calculation formula (1) for obtaining the shooting position pose in the preset calculation model is:

[0108]

[0109] The (x) N y N ) represents the image plane coordinates of the corresponding reference point in the photographic image with the principal point as the origin; f represents the principal distance of the interior orientation element; X S Y S Z S These represent the coordinates of the shooting position and pose in the ground coordinate system; X N Y N and Z N (N = 1, 2, ..., M, and N ≥ 3), representing the coordinates of the reference points in the ground coordinate system, where N represents the reference point number; a i b i c i (i = 1, 2, 3) are the nine direction cosines composed of the three exterior azimuth elements of the camera.

[0110] It should be noted that the actual data of the reference point includes the coordinates of the reference point in the ground coordinate system, and the photographic data of the reference point includes the image plane coordinates of the reference point in the photographic image with the principal point as the origin. Substitute the coordinates of the reference point in the ground coordinate system and the image plane coordinates with the principal point as the origin into the calculation formula (1) and perform adjustment calculation. A set of two collinear equations is determined by one image point. When the number of reference points is equal to 3, three sets of six collinear equations are obtained. The collinear equations can be solved to obtain the coordinates of the corresponding photographic position pose and the three exterior orientation elements of the image. By traversing the entire photographic data and actual data of the reference point, the photographic position pose set composed of the photographic position coordinates can be obtained.

[0111] refer to Figure 4 , Figure 4 A schematic diagram of the measurement point coordinate calculation is shown. According to an embodiment of the present invention, the step of sending any two data points from the photographic position pose set and the measurement point photographic data to a preset calculation model to obtain the coordinate set information of all measurement points specifically involves:

[0112] Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained;

[0113] Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained;

[0114] Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point;

[0115] Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points {A}. n-j}, where A n This indicates the measurement point labeled n, and j indicates the number of coordinate points of the measurement point labeled n;

[0116] The calculation formula (2) for obtaining the coordinates of the measurement point in the ground coordinate system from the preset calculation model is as follows:

[0117]

[0118] The (x) A y A (X) represents the image plane coordinates of measurement point A in the photographic image, with the principal point as the origin; A Y A Z A () represents the coordinates of measurement point A in the ground coordinate system. The pose coordinates of the corresponding photography position.

[0119] It should be noted that by substituting any two data points from the photography position and pose set and the image plane coordinates of the measurement point in the photographic image with the principal point as the origin into the calculation formula (2), and combining them with the exterior azimuth elements of the image obtained from the calculation formula (1), two sets of four collinear equations are obtained. Solving these equations yields the coordinates of the corresponding measurement point in the ground coordinate system. Any two data points from the photography position and pose set are used to photograph the same measurement point. Figure 4 As shown, if there are 3 photography points to take pictures of measurement point A, the coordinate data of the three measurement points A can be obtained by substituting S1 and S2, S1 and S3, and S2 and S3 into the calculation formula (2) respectively.

[0120] According to an embodiment of the present invention, the average distance value of the coordinates in the same subset of measurement point coordinates is calculated, specifically as follows:

[0121] Connect the coordinates of the same measurement point in pairs and calculate the distance between them;

[0122] The average distance d between the coordinates of the same measurement point subset and other coordinates is calculated by summing the distances and taking the mean value. The formula is as follows:

[0123]

[0124] Where μ∈j, This represents the average distance between the μ-th coordinate point among the measurement points labeled n. This represents the coordinates of the μ-th coordinate point among the measurement points labeled n.

[0125] It should be noted that the subset of coordinates for the same measurement point includes multiple coordinate point data for the corresponding measurement point. Connecting each pair of coordinate points from the same measurement point yields the average distance between that coordinate point and all other coordinate points. This average distance is the point-to-point distance value for the coordinates within the subset of coordinates for the same measurement point. For example, measurement point number 1 has 6 coordinates, and the average distance values ​​for each coordinate point and all other coordinates are as follows:

[0126] According to an embodiment of the present invention, it further includes:

[0127] Determine whether the average distance between coordinates in the same subset of measurement points is greater than a preset average distance threshold. If yes, the average distance is set to unqualified; otherwise, the average distance is qualified.

[0128] Arrange the average distance values ​​of the non-compliant points in descending order to obtain the maximum average distance of the non-compliant points;

[0129] The coordinates corresponding to the maximum average distance of the unqualified points are deleted, and the average distance of the coordinates in the same subset of measurement points is recalculated.

[0130] It should be noted that when the average distance between coordinate points is greater than a preset average distance threshold, it indicates that there are unqualified coordinates among the corresponding measurement points. For example, if the preset average distance threshold is set to d0, then the average distance of points greater than d0 is considered unqualified. The maximum average distance of unqualified points is extracted, and the coordinates corresponding to the maximum average distance of unqualified points are deleted to obtain a new subset of coordinates of the same measurement point. The average distance of coordinates in the new subset of coordinates of the same measurement point is calculated until the average distance of coordinates in the subset of coordinates of the same measurement point is less than or equal to the average distance threshold.

[0131] According to embodiments of the present invention, it further includes;

[0132] Obtain the number of qualified coordinates in the same subset of coordinates of a measurement point;

[0133] Determine whether the number of qualified coordinates in the same subset of coordinates of the same measurement point is greater than a preset threshold. If not, increase the measurement angle for that measurement point; otherwise, no increase is required.

[0134] It should be noted that the number of qualified coordinates in the same subset of coordinates of a measurement point should be greater than the preset number threshold. For example, if the preset number threshold is 4, then when there are 4 or fewer qualified coordinates in the same subset of coordinates of a measurement point, photogrammetry needs to be added to that measurement point.

[0135] According to an embodiment of the present invention, it further includes:

[0136] Obtain the angle information of the photography location and the measurement point;

[0137] Determine whether the angle between the photographic position and the measurement point and the angle between other photographic positions and the corresponding measurement point is greater than a preset angle threshold. If so, the photographic measurement data of the corresponding photographic position is valid; otherwise, take one of them.

[0138] It should be noted that, in order to prevent interference at the same angle from causing deviations in the photographic data, the angles between the photographic positions and the measurement point should maintain a certain angle difference. The preset angle thresholds include preset horizontal angle thresholds and preset vertical angle thresholds. For example, the preset angle threshold is 10 degrees. When the angle between the photographic position and the measurement point is greater than 10 degrees compared to the horizontal or vertical angle difference between other photographic positions and the measurement point, the photographic measurement data obtained at the corresponding photographic position are all valid data. Otherwise, only one photographic data within the preset angle threshold is taken.

[0139] Figure 2 A schematic diagram of collinearity constraints is shown.

[0140] like Figure 2 As shown, the camera center is set to S, the image point to a, and the object point to A. All three points lie on the same straight line. The principal image point (center of the image plane) is set to the origin O of the plane coordinate system. During imaging, image point a should be behind S. By performing a symmetrical transformation between image point a and the camera center S, a collinearity constraint diagram is obtained.

[0141] Figure 5 A block diagram of a multi-angle photogrammetry system according to the present invention is shown.

[0142] like Figure 5 As shown, a second aspect of the present invention provides a multi-angle photogrammetry system 5, including a memory 51 and a processor 52. The memory stores a multi-angle photogrammetry method program, which, when executed by the processor, performs the following steps:

[0143] Acquire photographic data and actual data information of reference points;

[0144] Based on the photographic data information, reference point photographic data and measurement point photographic data information are obtained;

[0145] The reference point photographic data and the actual reference point data are sent to the preset calculation model to obtain the photographic position pose set information;

[0146] Send any two data points from the photographic position pose set and the photographic data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points;

[0147] Extract the coordinate subset of the same measurement point from the coordinate set of all measurement points, and calculate the average distance between the coordinates of the same measurement point subset to obtain the average distance between the coordinates of the same measurement point subset.

[0148] Extract the minimum value of the average distance between coordinates in the same subset of measurement points, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point.

[0149] It should be noted that the preset calculation model includes the collinearity equation for photogrammetry. Based on the collinearity constraint of photography, the camera center (light point), image point (measurement point or reference point in the photographic image), and object point (measurement point or reference point) are on the same straight line. Based on multi-angle photographic data and actual reference point data, the collinearity equation is used to obtain the coordinate set of all measurement points. This coordinate set contains multiple photogrammetric data points for the same measurement point. Then, the minimum average distance among the multiple photogrammetric data points for the same measurement point is determined by calculating the average distance. The coordinates corresponding to the minimum average distance are set as the final coordinates of that measurement point.

[0150] According to an embodiment of the present invention, it further includes:

[0151] Obtain information about the object to be measured;

[0152] Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained;

[0153] Set the corners or endpoints of the object to be measured as measurement points.

[0154] It should be noted that measurement is achieved by extracting the corner points or endpoints of the object to be measured, thus reducing the workload of photogrammetry. For example, if the distance between two points is to be measured, the two endpoints of the distance are set as measurement points.

[0155] refer to Figure 3 , Figure 3 A schematic diagram of photographic position and pose calculation is shown. According to an embodiment of the present invention, the step of sending the photographic data of the reference point and the actual data of the reference point to a preset calculation model to obtain the photographic position and pose set information specifically involves:

[0156] Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained;

[0157] Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained;

[0158] The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position pose set {P1, P2, ..., P}. m},in

[0159] The calculation formula (1) for obtaining the shooting position pose in the preset calculation model is:

[0160]

[0161] The (x) Ny N ) represents the image plane coordinates of the corresponding reference point in the photographic image with the principal point as the origin; f represents the principal distance of the interior orientation element; X S Y S Z S These represent the coordinates of the shooting position and pose in the ground coordinate system; X N Y N and Z N (N = 1, 2, ..., M, and N ≥ 3), representing the coordinates of the reference points in the ground coordinate system, where N represents the reference point number; a i b i c i (i = 1, 2, 3) are the nine direction cosines composed of the three exterior azimuth elements of the camera.

[0162] It should be noted that the actual data of the reference point includes the coordinates of the reference point in the ground coordinate system, and the photographic data of the reference point includes the image plane coordinates of the reference point in the photographic image with the principal point as the origin. Substitute the coordinates of the reference point in the ground coordinate system and the image plane coordinates with the principal point as the origin into the calculation formula (1) and perform adjustment calculation. A set of two collinear equations is determined by one image point. When the number of reference points is equal to 3, three sets of six collinear equations are obtained. The collinear equations can be solved to obtain the coordinates of the corresponding photographic position pose and the three exterior orientation elements of the image. By traversing the entire photographic data and actual data of the reference point, the photographic position pose set composed of the photographic position coordinates can be obtained.

[0163] refer to Figure 4 , Figure 4 A schematic diagram of the measurement point coordinate calculation is shown. According to an embodiment of the present invention, the step of sending any two data points from the photographic position pose set and the measurement point photographic data to a preset calculation model to obtain the coordinate set information of all measurement points specifically involves:

[0164] Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained;

[0165] Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained;

[0166] Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point;

[0167] Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points {A}. n-j}, where A nThis indicates the measurement point labeled n, and j indicates the number of coordinate points of the measurement point labeled n;

[0168] The calculation formula (2) for obtaining the coordinates of the measurement point in the ground coordinate system from the preset calculation model is as follows:

[0169]

[0170] The (x) A y A (X) represents the image plane coordinates of measurement point A in the photographic image, with the principal point as the origin; A Y A Z A () represents the coordinates of measurement point A in the ground coordinate system. The pose coordinates of the corresponding photography position.

[0171] It should be noted that by substituting any two data points from the photography position and pose set and the image plane coordinates of the measurement point in the photographic image with the principal point as the origin into the calculation formula (2), and combining them with the exterior azimuth elements of the image obtained from the calculation formula (1), two sets of four collinear equations are obtained. Solving these equations yields the coordinates of the corresponding measurement point in the ground coordinate system. Any two data points from the photography position and pose set are used to photograph the same measurement point. Figure 4 As shown, if there are 3 photography points to take pictures of measurement point A, the coordinate data of the three measurement points A can be obtained by substituting S1 and S2, S1 and S3, and S2 and S3 into the calculation formula (2) respectively.

[0172] According to an embodiment of the present invention, the average distance value of the coordinates in the same subset of measurement point coordinates is calculated, specifically as follows:

[0173] Connect the coordinates of the same measurement point in pairs and calculate the distance between them;

[0174] The average distance d between the coordinates of the same measurement point subset and other coordinates is calculated by summing the distances and taking the mean value. The formula is as follows:

[0175]

[0176] Where μ∈j, This represents the average distance between the μ-th coordinate point among the measurement points labeled n. This represents the coordinates of the μ-th coordinate point among the measurement points labeled n.

[0177] It should be noted that the subset of coordinates for the same measurement point includes multiple coordinate point data for the corresponding measurement point. Connecting each pair of coordinate points from the same measurement point yields the average distance between that coordinate point and all other coordinate points. This average distance is the point-to-point distance value for the coordinates within the subset of coordinates for the same measurement point. For example, measurement point number 1 has 6 coordinates, and the average distance values ​​for each coordinate point and all other coordinates are as follows:

[0178] According to an embodiment of the present invention, it further includes:

[0179] Determine whether the average distance between coordinates in the same subset of measurement points is greater than a preset average distance threshold. If yes, the average distance is set to unqualified; otherwise, the average distance is qualified.

[0180] Arrange the average distance values ​​of the non-compliant points in descending order to obtain the maximum average distance of the non-compliant points;

[0181] The coordinates corresponding to the maximum average distance of the unqualified points are deleted, and the average distance of the coordinates in the same subset of measurement points is recalculated.

[0182] It should be noted that when the average distance between coordinate points is greater than a preset average distance threshold, it indicates that there are unqualified coordinates among the corresponding measurement points. For example, if the preset average distance threshold is set to d0, then the average distance of points greater than d0 is considered unqualified. The maximum average distance of unqualified points is extracted, and the coordinates corresponding to the maximum average distance of unqualified points are deleted to obtain a new subset of coordinates of the same measurement point. The average distance of coordinates in the new subset of coordinates of the same measurement point is calculated until the average distance of coordinates in the subset of coordinates of the same measurement point is less than or equal to the average distance threshold.

[0183] According to embodiments of the present invention, it further includes;

[0184] Obtain the number of qualified coordinates in the same subset of coordinates of a measurement point;

[0185] Determine whether the number of qualified coordinates in the same subset of coordinates of the same measurement point is greater than a preset threshold. If not, increase the measurement angle for that measurement point; otherwise, no increase is required.

[0186] It should be noted that the number of qualified coordinates in the same subset of coordinates of a measurement point should be greater than the preset number threshold. For example, if the preset number threshold is 4, then when there are 4 or fewer qualified coordinates in the same subset of coordinates of a measurement point, photogrammetry needs to be added to that measurement point.

[0187] According to an embodiment of the present invention, it further includes:

[0188] Obtain the angle information of the photography location and the measurement point;

[0189] Determine whether the angle between the photographic position and the measurement point and the angle between other photographic positions and the corresponding measurement point is greater than a preset angle threshold. If so, the photographic measurement data of the corresponding photographic position is valid; otherwise, take one of them.

[0190] It should be noted that, in order to prevent interference at the same angle from causing deviations in the photographic data, the angles between the photographic positions and the measurement point should maintain a certain angle difference. The preset angle thresholds include preset horizontal angle thresholds and preset vertical angle thresholds. For example, the preset angle threshold is 10 degrees. When the angle between the photographic position and the measurement point is greater than 10 degrees compared to the horizontal or vertical angle difference between other photographic positions and the measurement point, the photographic measurement data obtained at the corresponding photographic position are all valid data. Otherwise, only one photographic data within the preset angle threshold is taken.

[0191] This invention discloses a multi-angle photogrammetry method and system. The method includes: acquiring photographic data and actual reference point data; obtaining reference point photographic data and measurement point photographic data based on the photographic data; sending the reference point photographic data and actual reference point data to a preset calculation model to obtain a set of photographic position poses; sending any two data points from the photographic position poses set and the measurement point photographic data to the preset calculation model to obtain a set of coordinates for all measurement points; extracting a subset of coordinates for the same measurement point from all the coordinate sets, and calculating the average distance between the coordinates in the subset to obtain the average distance between the coordinates of the same measurement point; extracting the minimum value among the average distances between the coordinates in the subset, and setting the coordinates corresponding to the minimum value as the final coordinates of the measurement point. This invention improves the accuracy of photogrammetry.

[0192] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0193] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0194] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0195] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0196] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

Claims

1. A multi-angle photogrammetry method, characterized in that, include: Acquire photographic data and actual data information of reference points; Based on the photographic data information, reference point photographic data and measurement point photographic data information are obtained; The reference point photographic data and the actual reference point data are sent to the preset calculation model to obtain the photographic position pose set information; Send any two data points from the photographic position pose set and the photographic data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points; Extract the coordinate subset of the same measurement point from the coordinate set of all measurement points, and calculate the average distance between the coordinates of the same measurement point subset to obtain the average distance between the coordinates of the same measurement point subset. Extract the minimum value of the average distance between points in the same subset of coordinates of the same measurement point, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point; The step of sending any two data points from the photographic position pose set and the photographic data of the measurement points to the preset calculation model to obtain the coordinate set information of all measurement points is as follows: Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained; Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained; Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point; Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points.

2. The multi-angle photogrammetry method according to claim 1, characterized in that, Also includes: Obtain information about the object to be measured; Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained; Set the corners or endpoints of the object to be measured as measurement points.

3. The multi-angle photogrammetry method according to claim 1, characterized in that, The step of sending the reference point photographic data and the actual reference point data to a preset calculation model to obtain the photographic position pose set information is as follows: Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained; Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained; The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position and pose set. ,in ; The calculation formula (1) for obtaining the shooting position pose in the preset calculation model is: This represents the image plane coordinates of the corresponding reference point in the photographic image, with the principal point as the origin; f represents the principal distance of the interior orientation element. , , These represent the coordinates of the shooting position and pose in the ground coordinate system; , and , respectively represent the coordinates of the reference point in the ground coordinate system, and N represents the reference point number; The nine direction cosines are composed of the three exterior azimuth elements of the camera.

4. The multi-angle photogrammetry method according to claim 1, characterized in that, The calculation formula (2) for obtaining the coordinates of the measurement point in the ground coordinate system from the preset calculation model is as follows: This represents the image plane coordinates of measurement point A in the photographic image, with the principal point of the image as the origin. () represents the coordinates of measurement point A in the ground coordinate system. The corresponding shooting position pose coordinates.

5. The multi-angle photogrammetry method according to claim 4, characterized in that, The average distance between the coordinates of the same measurement point subset is calculated as follows: Connect the coordinates of the same measurement point in pairs and calculate the distance between them; The average distance d between the coordinates of the same measurement point subset and other coordinates is calculated by summing the distances and taking the mean value. The formula is as follows: in , This indicates the nth measurement point. The average distance between the coordinate points, ( ) represents the nth measurement point among the measurement points labeled n. The coordinates of each point.

6. The multi-angle photogrammetry method according to claim 5, characterized in that, Also includes: Determine whether the average distance between coordinates in the same subset of measurement points is greater than a preset average distance threshold. If yes, the average distance is set to unqualified; otherwise, the average distance is qualified. Arrange the average distance values ​​of the non-compliant points in descending order to obtain the maximum average distance of the non-compliant points; The coordinates corresponding to the maximum average distance of the unqualified points are deleted, and the average distance of the coordinates in the same subset of measurement points is recalculated.

7. The multi-angle photogrammetry method according to claim 6, characterized in that, Also includes; Obtain the number of qualified coordinates in the same subset of coordinates of a measurement point; Determine whether the number of qualified coordinates in the same subset of coordinates of the same measurement point is greater than a preset threshold. If not, increase the measurement angle for that measurement point; otherwise, no increase is required.

8. A multi-angle photogrammetry system, characterized in that, The system includes a memory and a processor. The memory stores a program for a multi-angle photogrammetry method. When the processor executes the program for the multi-angle photogrammetry method, it performs the following steps: Acquire photographic data and actual data information of reference points; Based on the photographic data information, reference point photographic data and measurement point photographic data information are obtained; The reference point photographic data and the actual reference point data are sent to the preset calculation model to obtain the photographic position pose set information; Send any two data points from the photographic position pose set and the photographic data of the measurement point to the preset calculation model to obtain the coordinate set information of all measurement points; Extract the coordinate subset of the same measurement point from the coordinate set of all measurement points, and calculate the average distance between the coordinates of the same measurement point subset to obtain the average distance between the coordinates of the same measurement point subset. Extract the minimum value of the average distance between points in the same subset of coordinates of the same measurement point, and set the coordinates corresponding to the minimum value as the final coordinates of the measurement point; The step of sending any two data points from the photographic position pose set and the photographic data of the measurement points to the preset calculation model to obtain the coordinate set information of all measurement points is as follows: Based on the photographic data of the measurement points, the size information of the measurement points in the photographic images is obtained; Using the principal point as the origin, and based on the size information of the measurement point in the photographic image, the image plane coordinate information of the measurement point in the photographic image with the principal point as the origin is obtained; Send any two data points from the photography position and pose set and the image plane coordinate information of the measurement point in the photograph with the principal point as the origin to the preset calculation model to obtain the coordinates of the corresponding measurement point; Traverse the entire set of photographic positions and poses to obtain the coordinate set of all measurement points.

9. A multi-angle photogrammetry system according to claim 8, characterized in that, Also includes: Obtain information about the object to be measured; Based on the information of the object to be measured, the corner or endpoint information of the object to be measured is obtained; Set the corners or endpoints of the object to be measured as measurement points.

10. A multi-angle photogrammetry system according to claim 8, characterized in that, The step of sending the reference point photographic data and the actual reference point data to a preset calculation model to obtain the photographic position pose set information is as follows: Based on the photographic data of the reference point, the size information of the reference point in the photographic image is obtained; Using the principal point as the origin, and based on the size information of the reference point in the photographic image, the image plane coordinate information of the reference point in the photographic image with the principal point as the origin is obtained; The image plane coordinates of the reference point in the photographic image, with the principal point as the origin, and the actual data of the reference point are sent to the preset calculation model to obtain the photographic position and pose set. ,in ; The calculation formula (1) for obtaining the shooting position pose from the preset calculation model is: The This represents the image plane coordinates of the corresponding reference point in the photographic image, with the principal point as the origin; f represents the principal distance of the interior orientation element. , , These represent the coordinates of the shooting position and pose in the ground coordinate system; , and , respectively represent the coordinates of the reference point in the ground coordinate system, and N represents the reference point number; The nine direction cosines are composed of the three exterior azimuth elements of the camera.

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