Aerial photography system and lens auxiliary component thereof

Abstract

The present invention discloses an aerial photography system and a lens auxiliary component thereof, belonging to the technical field of photographic devices, comprising a central camera unit, a left camera unit and a right camera unit with a three-dimensional laser scanning system, wherein the left camera unit and the right camera unit constitute a dual-camera system, and the left camera unit and the right camera unit respectively constitute two single-camera systems with the central camera unit. The present invention utilizes the single-camera system and the dual-camera system to scan the surface of an object, and generates point cloud data representing the shape and structure of the object; and obtains high-precision point cloud data by screening the overlapping area of ​​the single-camera system and the dual-camera system, and then samples and reconstructs a multi-dimensional model image; through the point cloud system accuracy model, the accuracy of the point cloud model and the space coordinates can be adjusted within the accuracy range according to the number of reference points, thereby generating a high-precision point cloud model; the calibration of the overlapping area of ​​the single-camera system and the dual-camera system can reduce the error during the reconstruction of the multi-dimensional model image, thereby improving the position accuracy.

Description

Technical Field

[0001] The invention discloses a photographic device technology, and in particular relates to an aerial photography system and a lens auxiliary component thereof. Background Art

[0002] In the field of aerial photography and other photographic technologies, when long- and short-range photographic images are transmitted to display instruments, in addition to being affected by natural factors such as shooting brightness and weather visibility, equipment and systems such as lens assemblies and imaging systems will also affect the quality and accuracy of the images. During actual shooting, there is a difference between the spatial image and the measurement of the photographic device on the subject, so it is necessary to use lens assemblies and imaging systems to sample and reconstruct the image of the subject presented in the display instrument. However, the imaging quality and accuracy of the sampling and reconstruction technology of existing lens assemblies and imaging systems have certain limitations, resulting in inaccurate position accuracy of the images from aerial photography to display instruments, especially in the process of scientific research such as geological exploration using drones, which requires sufficient position accuracy and multi-dimensional model image generation. Summary of the invention

[0003] The purpose of the present invention is to provide an aerial photography system and a lens auxiliary component thereof in order to solve the above-mentioned problems.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an aerial photography system, comprising a central camera unit with a three-dimensional laser scanning system, a left camera unit and a right camera unit, wherein the left camera unit and the right camera unit constitute a dual-camera system, and the left camera unit and the right camera unit respectively constitute two single-camera systems with the central camera unit, and the dual-camera system and the single-camera system construct a sampling and reconstruction imaging process as follows:

[0005] M1, the single-camera system and the dual-camera system are calibrated and the coordinate system is established respectively. The imaging model of the single-camera system or the dual-camera system is as follows:

[0006] S1, assuming that the spatial coordinates of the object in space are (X, Y, Z), and the convergence or divergence of the lens is F, ( , , ) is about the lens focus Dimensional coordinates, ( , ) is the deviation coordinate of the lens on the imaging plane, is the coordinate deviation on the imaging plane, and the relationship between the spatial coordinates and the dimensional coordinates is:

[0007] ;

[0008] R is a 3*3 rotation matrix, T is a 3*1 displacement matrix, and a, b, c, d, e, f, g, h, i are the elements in the rotation matrix R. The relationship between the actual imaging line equations of the imaging model is as follows:

[0009] ;

[0010] ;

[0011] S2, the imaging model is established based on the radial, eccentric and dimensional quantities of the camera lens, and the lens coordinate deviation is:

[0012] ;

[0013] ;

[0014] in, , , is the radial mass coefficient, and is the eccentricity coefficient, and is the dimension coefficient, the central horizontal coordinate , center ordinate , is the radial offset, ;

[0015] M2, the point cloud system accuracy model is established as follows:

[0016] K1, convert the spatial coordinates and dimensional coordinates into point cloud models, calculate the accuracy of the converted point cloud data, and average spatial accuracy Represents the average deviation between point cloud data and spatial coordinates, accuracy standard deviation Indicates the degree of convergence between point cloud data and spatial coordinates, average spatial accuracy and precision standard deviation There is the following relationship:

[0017] ;

[0018] ;

[0019] Among them, n is the number of reference points used when converting the spatial coordinates and dimensional coordinates into a point cloud model. Focus of lens and the Euclidean distance between the reference point;

[0020] K2, using the root mean square error As an accuracy indicator, there is the following relationship:

[0021] ;

[0022] Among them, H is the measurement value of the dual-camera system, h is the measurement value of the single-camera system, is the error number;

[0023] K3: Set the objects photographed by the dual-camera system and the single-camera system as any point in a certain space. Composition, assumption There are k neighboring points , establish about point Local domain model , construct the covariance matrix ,

[0024] ;

[0025] in, for With k neighboring points The average distance ( = ), Represents matrix transpose;

[0026] K4, covariance matrix Perform eigenvalue decomposition to obtain eigenvalues , , ,

[0027] and ≥ ≥ ≥0, definition The line eigenvalue is L, the surface eigenvalue is P, the volume eigenvalue is S, and the anisotropic eigenvalue is , then we have the following relationship:

[0028] ;

[0029] ;

[0030] ;

[0031] ;

[0032] K5, L, P, S, Integrate into dimension features In ;

[0033] K6, set different groups of points q and w in the space, and their corresponding matrices are and , using the correlation express and The relationship between the two is the correlation = ,in is the set correlation coefficient;

[0034] K7, screening correlation 0.01 < <0.05 Neighborhood points The features are counted into the point cloud model U, and N is the neighborhood point The number of items, .

[0035] Preferably, the point cloud models obtained by the single-camera system and the dual-camera system are defined as and , and There is an overlap between the domain densities ,

[0036] ;

[0037] Keep adjusting The value of The value of is maximized, that is, the single-camera system and the dual-camera system and The overlap domain is the largest, output and The sampled and reconstructed multi-dimensional model image can be obtained by placing it on the imaging model.

[0038] A lens auxiliary component of an aerial photography system adopts an aerial photography system, comprising an objective lens, an imaging surface, and an optical auxiliary component installed between the objective lens and the imaging surface, and comprising, from the objective lens direction to the imaging surface, a double convex lens L1, a triplet lens group TL composed of lens L2, lens L3, and lens L4, and a doublet lens group DL composed of lens L5 and lens L6.

[0039] Preferably, a magnifying lens is further provided between the imaging surface and the double cemented lens group DL, and the entrance pupil position of the magnifying lens and the exit pupil position of the objective lens satisfy the range: [-0.2d', 0.2d'], wherein d' is the exit pupil distance of the objective lens.

[0040] Preferably, the total back focal length D of the optical auxiliary component satisfies: D≥0.3|f'|, wherein f' is the focal length of the magnification lens.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This lens auxiliary component is a three-group, six-piece structure. It is used for large zoom ratio imaging objective lenses and small field of view telephoto objective lenses to compress the field of view, obtain a larger imaging magnification, and achieve imaging magnification. It is equipped with a post-compensation filter group to achieve free switching between the visible light and near-infrared band spectral working states.

[0043] The single-camera system and the dual-camera system are used to scan the surface of the object to generate point cloud data representing the shape and structure of the object; and high-precision point cloud data is obtained by screening the overlapping area of ​​the single-camera system and the dual-camera system, and then sampling and reconstructing the multi-dimensional model image; the point cloud system precision model can adjust the accuracy of the point cloud model and spatial coordinates within the precision range according to the number of reference points, thereby generating a high-precision point cloud model; the calibration of the overlapping area of ​​the single-camera system and the dual-camera system can reduce the error in reconstructing the multi-dimensional model image, thereby improving the position accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the structure of the lens auxiliary component Figure 1 ;

[0045] Figure 2 Schematic diagram of the structure of the lens auxiliary component Figure 2 ;

[0046] Figure 3 Schematic diagram of the post-compensation filter set;

[0047] Figure 4 A simplified diagram of the positional relationship between the object, lens, and imaging surface in an aerial photography system;

[0048] Figure 5 Field of view parameter diagram for the working spectrum of the lens auxiliary component. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] A lens auxiliary component of an aerial photography system, such as Figure 1-Figure 2 As shown, it includes an objective lens, an imaging surface, and an optical auxiliary component installed between the objective lens and the imaging surface, and includes, from the objective lens direction to the imaging surface, a biconvex lens L1, a triplet lens group TL composed of lens L2, lens L3, and lens L4, and a doublet lens group DL composed of lens L5 and lens L6. The specific implementation scheme parameters are as shown in Table 1:

[0052] Table 1

[0053]

[0054] A magnifying lens is also provided between the imaging surface and the double cemented lens group DL, and the entrance pupil position of the magnifying lens and the exit pupil position of the objective lens satisfy the range: [-0.2d', 0.2d'], where d' is the exit pupil distance of the objective lens;

[0055] The total back focal length D of the optical auxiliary assembly satisfies: D ≥ 0.3│f'│, where f' is the focal length of the magnification lens; the working spectrum is as follows Figure 5 As shown, the range is 0.45~0.92 microns, among which the vertical axis chromatic aberration of the system in the visible light band of 0.45~0.62 microns is less than 0.025Ar, where Ar is the diameter of the Eriban.

[0056] like Figure 3 The figure shows a schematic diagram of a post-compensation filter set, wherein the optical path difference of two spectral filters │nd*d1-ns*d2│ satisfies: 0≤│nd*d1-ns*d2│≤0.025×│f│, wherein nd is the nano-refractive index of material model 1 at a wavelength of 587.5618, ns is the nano-refractive index of material model 2 at a wavelength of 852.11, and d1 and d2 are the thicknesses of the visible light and near-infrared filters, respectively;

[0057] This lens auxiliary component uses a three-group, six-piece structure to compress the field of view, obtain a larger imaging magnification, and achieve imaging magnification for large zoom ratio imaging objectives and small field of view telephoto objectives. It is equipped with a post-compensation filter group to achieve free switching of the visible light and near-infrared band spectral working states.

[0058] Example 2

[0059] An aerial photography system includes a central camera unit with a three-dimensional laser scanning system, a left camera unit and a right camera unit. The left camera unit and the right camera unit constitute a dual-camera system, and the left camera unit and the right camera unit respectively constitute two single-camera systems with the central camera unit. The dual-camera system and the single-camera system construct sampling and reconstruction imaging processes as follows:

[0060] M1, the single-camera system and the dual-camera system are calibrated and the coordinate system is established respectively. The imaging model of the single-camera system or the dual-camera system is as follows:

[0061] S1, such as Figure 4 As shown, assuming that the spatial coordinates of the object in space are (X, Y, Z), the convergence or divergence of the lens is F, ( , , ) is about the lens focus Dimensional coordinates, ( , ) is the deviation coordinate of the lens on the imaging plane, is the coordinate deviation on the imaging plane, and the relationship between the spatial coordinates and the dimensional coordinates is:

[0062] ;

[0063] R is a 3*3 rotation matrix, T is a 3*1 displacement matrix, and a, b, c, d, e, f, g, h, i are the elements in the rotation matrix R. The relationship between the actual imaging line equations of the imaging model is as follows:

[0064] ;

[0065] ;

[0066] S2, the imaging model is established based on the radial, eccentric and dimensional quantities of the camera lens, and the lens coordinate deviation is:

[0067] ;

[0068] ;

[0069] in, , , is the radial mass coefficient, and is the eccentricity coefficient, and is the dimension coefficient, the central horizontal coordinate , center ordinate , is the radial offset, ;

[0070] M2, the point cloud system accuracy model is established as follows:

[0071] K1, convert the spatial coordinates and dimensional coordinates into point cloud models, calculate the accuracy of the converted point cloud data, and average spatial accuracy Represents the average deviation between point cloud data and spatial coordinates, accuracy standard deviation Indicates the degree of convergence between point cloud data and spatial coordinates, average spatial accuracy and precision standard deviation There is the following relationship:

[0072] ;

[0073] ;

[0074] Among them, n is the number of reference points used when converting the spatial coordinates and dimensional coordinates into a point cloud model. Focus of lens and the Euclidean distance between the reference point;

[0075] K2, using the root mean square error As an accuracy indicator, there is the following relationship:

[0076] ;

[0077] Among them, H is the measurement value of the dual-camera system, h is the measurement value of the single-camera system, is the error number;

[0078] K3: Set the objects photographed by the dual-camera system and the single-camera system as any point in a certain space. Composition, assumption There are k neighboring points , establish about point Local domain model , construct the covariance matrix ,

[0079] ;

[0080] in, for With k neighboring points The average distance ( = ), Represents matrix transpose;

[0081] K4, covariance matrix Perform eigenvalue decomposition to obtain eigenvalues , , ,

[0082] and ≥ ≥ ≥0, definition The line eigenvalue is L, the surface eigenvalue is P, the volume eigenvalue is S, and the anisotropic eigenvalue is , then we have the following relationship:

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] K5, L, P, S, Integrate into dimension features In ;

[0088] K6, set different groups of points q and w in the space, and their corresponding matrices are and , using the correlation express and The relationship between the two is the correlation = ,in is the set correlation coefficient;

[0089] K7, screening correlation 0.01 < <0.05 Neighborhood points The features are counted into the point cloud model U, and N is the neighborhood point The number of items,

[0090] .

[0091] The point cloud models obtained by the single-camera system and the dual-camera system are defined as and , and There is an overlap between the domain densities ,

[0092] ;

[0093] Keep adjusting The value of The value of is maximized, that is, the single-camera system and the dual-camera system and The overlap domain is the largest, output and By placing the sampled and reconstructed multidimensional model image on the imaging model, the single-camera system and the dual-camera system can be used to scan the surface of the object to generate point cloud data representing the shape and structure of the object; and by screening the overlapping area of ​​the single-camera system and the dual-camera system, high-precision point cloud data can be obtained, and then the multidimensional model image can be sampled and reconstructed; through the point cloud system accuracy model, the accuracy of the point cloud model and spatial coordinates can be adjusted within the accuracy range according to the number of reference points, thereby generating a high-precision point cloud model; the calibration of the overlapping area of ​​the single-camera system and the dual-camera system can reduce the error in reconstructing the multidimensional model image, thereby improving the position accuracy.

[0094] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0095] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An aerial photography system, characterized in that: It includes a central camera unit with a three-dimensional laser scanning system, a left camera unit and a right camera unit. The left camera unit and the right camera unit constitute a dual-camera system, and the left camera unit and the right camera unit respectively constitute two single-camera systems with the central camera unit. The dual-camera system and the single-camera system construct a sampling and reconstruction imaging process as follows: M1, the single-camera system and the dual-camera system are calibrated and the coordinate system is established respectively. The imaging model of the single-camera system or the dual-camera system is as follows: S1, assuming that the spatial coordinates of the object in space are (X, Y, Z), and the convergence or divergence of the lens is F, ( , , ) is about the lens focus Dimensional coordinates, ( , ) is the deviation coordinate of the lens on the imaging plane, is the coordinate deviation on the imaging plane, and the relationship between the spatial coordinates and the dimensional coordinates is: ； R is a 3*3 rotation matrix, T is a 3*1 displacement matrix, and a, b, c, d, e, f, g, h, i are the elements in the rotation matrix R. The relationship between the actual imaging line equations of the imaging model is as follows: ； ； S2, the imaging model is established based on the radial, eccentric and dimensional quantities of the camera lens, and the lens coordinate deviation is: ； ； in, , , is the radial mass coefficient, and is the eccentricity coefficient, and is the dimension coefficient, the central horizontal coordinate , center ordinate , is the radial offset, ; M2, the point cloud system accuracy model is established as follows: K1, convert the spatial coordinates and dimensional coordinates into point cloud models, calculate the accuracy of the converted point cloud data, and average spatial accuracy Represents the average deviation between point cloud data and spatial coordinates, accuracy standard deviation Indicates the degree of convergence between point cloud data and spatial coordinates, average spatial accuracy and precision standard deviation There is the following relationship: ； ； Where n is the number of reference points used when converting the spatial coordinates and dimensional coordinates into a point cloud model. Focus of lens and the Euclidean distance between the reference point; K2, using the root mean square error As an accuracy indicator, there is the following relationship: ； Among them, H is the measurement value of the dual-camera system, h is the measurement value of the single-camera system, is the error number; K3: Set the objects photographed by the dual-camera system and the single-camera system as any point in a certain space. Composition, assumption There are k neighboring points , establish about point Local domain model , construct the covariance matrix , ； in, for With k neighboring points The average distance ( = ), Represents matrix transpose; K4, covariance matrix Perform eigenvalue decomposition to obtain eigenvalues , , , and ≥ ≥ ≥0, definition The line eigenvalue is L, the surface eigenvalue is P, the volume eigenvalue is S, and the anisotropic eigenvalue is , then we have the following relationship: ； ； ； ； K5, L, P, S, Integrate into dimension features In ; K6, set different groups of points q and w in the space, and their corresponding matrices are and , using the correlation express and The relationship between the two is the correlation = ,in is the set correlation coefficient; K7, screening correlation 0.01 < <0.05 Neighborhood points The features are counted into the point cloud model U, and N is the neighborhood point The number of items, 。 2. The aerial photography system according to claim 1, characterized in that: The point cloud models obtained by the single-camera system and the dual-camera system are defined as and , and There is an overlap between the domain densities , ； Keep adjusting The value of The value of is maximized, that is, the single-camera system and the dual-camera system and The overlap domain is the largest, output and The sampled and reconstructed multi-dimensional model image can be obtained by placing it on the imaging model.

3. A lens auxiliary component of an aerial photography system, using the aerial photography system as claimed in any one of claims 1 to 2, characterized in that: It includes an objective lens, an imaging surface, and an optical auxiliary component installed between the objective lens and the imaging surface, and includes, from the objective lens direction to the imaging surface, a double convex lens L1, a triplet lens group TL composed of lens L2, lens L3, and lens L4, and a doublet lens group DL composed of lens L5 and lens L6.

4. The lens auxiliary assembly of the aerial photography system according to claim 3, characterized in that: A magnifying lens is also provided between the imaging surface and the double cemented lens group DL, and the entrance pupil position of the magnifying lens and the exit pupil position of the objective lens satisfy the range: [-0.2d', 0.2d'], where d' is the exit pupil distance of the objective lens.

5. The lens auxiliary assembly of the aerial photography system according to claim 4, characterized in that: The total back focal length D of the optical auxiliary component satisfies: D≥0.3|f'|, wherein f' is the focal length of the magnification lens.

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