Wavefront joint quantitative distribution analysis and image quality evaluation method and device for three-mirror zoom system

Abstract

The invention provides a wavefront joint quantitative distribution analysis and image quality evaluation method and device for a three-mirror zoom system, and the method comprises the steps: obtaining the aberration change caused by the pupil position change in a zooming process based on the relation between a primary aberration coefficient and a diaphragm position, the optimal diaphragm position of the three-mirror zoom system is evaluated according to the aberration change; fitting the wave surface shape of an exit pupil in the three-mirror zoom system by using a Zernike polynomial, and evaluating the oscillation condition of the wave surface shape based on a fitting result; and the pupil wavefront before and after the position change of the diaphragm is analyzed, and the pupil wavefront deformation caused by the movement of the diaphragm is calculated, so that the full-focal-length image quality evaluation of the three-mirror zoom system is realized. According to the invention, the wavefront shape analysis at the exit pupil position of the varifocal three-mirror system under the full-focus section and the aberration coefficient and wavefront change analysis caused by pupil change can be realized, and a theoretical basis is provided for the subsequent directivity optimization design of an optical system.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic imaging technology, and in particular to a wavefront joint quantitative distribution analysis and image quality evaluation method and device for a three-mirror zoom system. Background Art

[0002] With the rapid development of imaging technology in recent years, users have higher and higher requirements for the quality of images generated by optical imaging systems. The dual requirements for wide field of view and high definition at telephoto increase the complexity of the imaging system, requiring it to meet complex aberration function requirements at multiple focal lengths and have stable imaging quality when the focal length changes.

[0003] The development of space optical systems has evolved from refractive systems to reflective systems. Due to the limitations of lens materials, refractive systems have problems such as limited aperture, difficulty in chromatic aberration correction, and difficulty in lightweighting. Reflective materials are easy to process, easy to scale up, lightweight, and have good heat resistance. After coating, they have high reflectivity in a wide band, and there is no chromatic aberration in the total reflection system. The design of the off-axis three-mirror optical system is based on Gaussian optical theory. The coaxial three-mirror optical system structure is taken as the initial structure, and the surface shape and spacing of the three mirrors are adjusted to achieve the purpose of eliminating aberrations such as spherical aberration, coma, and astigmatism.

[0004] Traditional image quality evaluation methods mainly use optical design software to evaluate the system's image quality parameters. However, this evaluation method cannot link the changes in system imaging quality at various focal lengths for the three-mirror zoom system, making it difficult to provide an accurate basis for the subsequent optimization design of the three-mirror zoom system. Summary of the invention

[0005] In view of this, the present invention provides a wavefront joint quantitative distribution analysis and image quality evaluation method and device for a three-mirror zoom system to solve at least one of the above-mentioned problems.

[0006] In order to achieve the above object, the present invention adopts the following scheme:

[0007] According to a first aspect of the present invention, a method for wavefront joint quantitative distribution analysis and image quality evaluation of a three-mirror zoom system is provided, the method comprising: obtaining aberration changes caused by changes in pupil position during zooming based on the relationship between primary aberration coefficients and diaphragm positions, and evaluating the optimal diaphragm position of the three-mirror zoom system according to the aberration changes; fitting the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials, and evaluating the oscillation of the wavefront shape based on the fitting results; analyzing the pupil wavefront before and after the diaphragm position change, calculating the wavefront deformation at the pupil caused by the diaphragm movement, and realizing the full-focal-length image quality evaluation of the three-mirror zoom system.

[0008] As an embodiment of the present invention, the method described in the above method obtains the aberration change caused by the change of the pupil position during the zooming process based on the relationship between the primary aberration coefficient and the aperture position, and evaluates the optimal aperture position of the three-reflector zoom system according to the aberration change, including: establishing a three-reflector zoom system according to the Gaussian bracket method and the system magnification relationship; setting an initial aperture position, adjusting the aperture position to analyze the influence of the aperture position change on the aberration coefficient of the three-reflector zoom system when the system magnification is changed, and evaluating the aberration of the three-reflector zoom system at the new aperture position; analyzing the aperture position for correcting the system aberration at the full focal length according to the change of the aberration coefficient of the three-reflector zoom system caused by the aperture position change; introducing an optimization function to analyze the aberration change of each position at the full focal length when the aperture position changes, and obtaining the optimal aperture position of the three-reflector zoom system.

[0009] As an embodiment of the present invention, the above method uses Zernike polynomials to fit the wavefront shape of the exit pupil in the three-mirror zoom system, and evaluates the oscillation of the wavefront shape based on the fitting results, including: using Zernike polynomials to fit the wavefront shape of the exit pupil in the three-mirror zoom system to obtain a wavefront expression; based on the wavefront expression obtained by fitting, analyzing the fluctuations of the wavefront shape to obtain the change of the wavefront at the full focal length of the three-mirror zoom system relative to the reference wavefront.

[0010] As an embodiment of the present invention, the above method analyzes the pupil wavefront before and after the aperture position changes, calculates the wavefront deformation at the pupil caused by the aperture movement, and realizes the full-focal-length image quality evaluation of the three-mirror zoom system, including: combining the image quality analysis of the aperture position change with the wavefront change at the exit pupil of the three-mirror zoom system to obtain the deformation of the wavefront as the aperture position changes when the light propagates in the free space; based on the analysis of the deformation of the wavefront as the aperture position changes, the change of the wave aberration coefficient as the aperture position moves is given; and the wavefront shape of the aperture position movement is evaluated and analyzed to obtain the image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths.

[0011] According to a second aspect of the present invention, there is provided a wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system, the device comprising: a first evaluation unit, for obtaining the aberration change caused by the change of pupil position during zooming based on the relationship between the primary aberration coefficient and the aperture position, and evaluating the optimal aperture position of the three-mirror zoom system according to the aberration change; a second evaluation unit, for fitting the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials, and evaluating the oscillation of the wavefront shape based on the fitting result; and a comprehensive evaluation unit, for analyzing the pupil wavefront before and after the aperture position changes, calculating the wavefront deformation at the pupil caused by the aperture movement, and realizing the full-focal-length image quality evaluation of the three-mirror zoom system.

[0012] As an embodiment of the present invention, the above-mentioned first evaluation unit includes: a system establishment module, which is used to establish a three-mirror zoom system according to the Gaussian bracket method and the system magnification relationship; an aberration evaluation module, which is used to set the initial aperture position, adjust the aperture position to analyze the influence of the aperture position change on the aberration coefficient of the three-mirror zoom system when the system magnification changes, and evaluate the aberration of the three-mirror zoom system under the new aperture position; an aperture position analysis module, which is used to analyze the aperture position for correcting the system aberration at the full focal length according to the change of the aberration coefficient of the three-mirror zoom system caused by the aperture position change; an optimal aperture position acquisition module, which is used to introduce an optimization function to analyze the aberration change of each position at the full focal length when the aperture position changes, and obtain the optimal aperture position of the three-mirror zoom system.

[0013] As an embodiment of the present invention, the above-mentioned second evaluation unit includes: a fitting module, which is used to use Zernike polynomials to fit the wavefront shape of the exit pupil in the three-mirror zoom system to obtain a wavefront expression; a wavefront shape analysis module, which is used to analyze the fluctuations of the wavefront shape according to the wavefront expression obtained by fitting, and obtain the change status of the wavefront of the three-mirror zoom system at the full focal length relative to the reference wavefront.

[0014] As an embodiment of the present invention, the above-mentioned comprehensive evaluation unit includes: a wavefront deformation acquisition module, which is used to combine the image quality analysis of the aperture position change with the wavefront change at the exit pupil of the three-mirror zoom system, so as to obtain the deformation of the wavefront as the aperture position changes when the light propagates in the free space; an aperture change acquisition module, which is used to give the change of the wave aberration coefficient as the aperture position moves based on the analysis of the deformation of the wavefront as the aperture position changes; an image quality analysis module, which is used to evaluate and analyze the wavefront shape of the aperture position movement, so as to obtain the image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths.

[0015] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the steps of the above method are implemented when the processor executes the computer program. In a fourth aspect, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the steps of the above method are implemented when the computer program is executed by the processor.

[0016] It can be seen from the above technical scheme that the wavefront joint quantitative distribution analysis and image quality evaluation method and device of the three-mirror zoom system provided by the present invention can realize the wavefront shape analysis at the exit pupil of the three-mirror system with variable focal length at the full focal length and the analysis of the aberration coefficient and wavefront change caused by the pupil change, thereby providing a theoretical basis for the subsequent directional optimization design of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0018] Figure 1 It is a flow chart of a wavefront joint quantitative distribution analysis and image quality evaluation method for a three-mirror zoom system provided by an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of a process for obtaining an optimal aperture position provided in an embodiment of the present application;

[0020] Figure 3 is a structural diagram of a short-focus position system using a three-reflector zoom structure provided in an embodiment of the present application;

[0021] Figure 4 is a structural diagram of a telephoto position system using a three-reflector zoom structure provided in an embodiment of the present application;

[0022] Figure 5 It is a schematic diagram of a flow chart for evaluating the oscillation condition of a wave surface shape provided in an embodiment of the present application;

[0023] Figure 6 It is a schematic diagram of a process for performing full-focal-length image quality evaluation provided by an embodiment of the present application;

[0024] Figure 7 It is a wavefront shape diagram at the exit pupil of a certain focal length when the optical system is located at the original aperture position provided by an embodiment of the present application;

[0025] Figure 8 It is a wavefront shape diagram at the exit pupil when the aperture position of the optical system changes and the wavefront fluctuates, provided by an embodiment of the present application;

[0026] Fig. 9 It is a structural schematic diagram of a wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system provided by an embodiment of the present invention;

[0027] Fig.10 is a structural schematic diagram of a first evaluation unit provided in an embodiment of the present invention;

[0028] Fig.11 is a structural schematic diagram of a second evaluation unit provided in an embodiment of the present invention;

[0029] Fig.12 is a schematic diagram of the structure of a comprehensive evaluation unit provided in an embodiment of the present invention;

[0030] Fig.13 It is a schematic block diagram of the system structure of the electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0032] As mentioned above, the traditional image quality evaluation method mainly uses optical design software to evaluate the system's image quality parameters. However, for zoom systems, this evaluation method cannot link the changes in system imaging quality at various focal lengths, making it difficult to provide an accurate basis for subsequent optimization design.

[0033] Therefore, it is necessary to further evaluate the wavefront shape of the zoom system, especially the need to evaluate the wavefront changes in the full field of view and full focal length, so as to provide feedback for the optimization design iteration of the zoom system, realize the optimization of specific areas of the zoom system, and finally realize the directional imaging quality improvement design process of the entire zoom system. In addition, for the zoom system, the position of the aperture in the zoom system has an important influence on the imaging quality of the zoom system. During the system zooming process, the pupil position changes with the change of the focal length and field of view of the zoom system, and exhibits different aberration characteristics. The appropriate aperture position can effectively eliminate the coma, astigmatism or distortion of the system. In order to achieve stable imaging of the zoom system within the full focal length range and smooth exit pupil wavefront, it is necessary to evaluate the specific changes in aberrations and wavefronts caused by changes in pupil position.

[0034] Based on the above reasons, the present invention proposes a wavefront joint quantitative distribution analysis and image quality evaluation method and device for a three-mirror zoom system, which can realize the analysis of the wavefront shape at the exit pupil of the three-mirror zoom system at all focal lengths and the analysis of the aberration coefficient and wavefront changes caused by pupil changes.

[0035] like Figure 1 FIG. 1 is a flow chart of a method for wavefront joint quantitative distribution analysis and image quality evaluation of a three-mirror zoom system provided by an embodiment of the present invention. The method comprises the following steps:

[0036] Step S101: obtaining aberration changes caused by changes in pupil position during zooming based on a relationship between a primary aberration coefficient and an aperture position, and evaluating an optimal aperture position of the three-mirror zoom system according to the aberration changes.

[0037] Step S102: fitting the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials, and evaluating the oscillation of the wavefront shape based on the fitting result.

[0038] Step S103: analyzing the pupil wavefront before and after the aperture position changes, calculating the wavefront deformation at the pupil caused by the aperture movement, and realizing the full-focal-length image quality evaluation of the three-mirror zoom system.

[0039] It can be seen from the above technical scheme that the wavefront joint quantitative distribution analysis and image quality evaluation method of the three-mirror zoom system provided by the present invention can realize the analysis of the wavefront shape at the exit pupil of the three-mirror zoom system with variable focal length at the full focal length and the analysis of the aberration coefficient and wavefront change caused by the pupil change, thereby providing a theoretical basis for the subsequent directional optimization design of the optical system.

[0040] Preferably, Figure 2 As shown, the above step S101 may further include the following sub-steps:

[0041] Step S1011: Establish a three-mirror zoom system according to the Gaussian bracket method and the system zoom relationship.

[0042] The Gaussian bracket method is a mathematical method used to analyze the propagation of light in optical systems. It helps designers understand and optimize the performance of optical systems by using matrices to describe the propagation characteristics of light in optical elements.

[0043] In this step, the Gauss bracket method is used to establish the fixed zoom equation of the three-mirror zoom system as follows:

[0044] Z= 1 A m+1 =[φ1,-d1,φ2-d2,...,φ m ,d m ]= 1 A3=[φ1,-d1,φ2,-d2,φ3,-d3];

[0045] In the above formula, Z represents the zoom equation parameter of the fixed zoom system. 1 A m+1 The Gaussian bracket method parameter characterizing the number of system components is m+1, 1 A3 represents the parameters of the fixed zoom equation of the three-mirror structure, φ1, φ2, ..., φ m Characterize the optical power of the i=1,2,3,...,m components, d1, d2,..., d m Characterizes the intervals between i=1, 2, 3, ..., m components.

[0046] The expression of the equivalent focal power Φ of the fixed zoom system expressed by the Gaussian constant is as follows:

[0047] Φ= 1 C m =[φ1,-d1,φ2,-d2,....,φ m ]=1 C3=[φ1,-d1,φ2,-d2,φ3]

[0048] In the above formula, 1 C m Characterizing the system components is m Gauss bracket method parameters, in this embodiment, 1 C3 characterizes the parameters of the fixed zoom equation of the three-mirror structure.

[0049] Furthermore, the schematic diagram of the three-mirror zoom system under short focal length and long focal length obtained according to the Gauss bracket method and the system zoom relationship can be shown as follows: Figure 3 and Figure 4 shown.

[0050] Step S1012: setting an initial aperture position, adjusting the aperture position to analyze the influence of the aperture position change on the aberration coefficient of the three-mirror zoom system when the system zooms, and evaluating the aberration of the three-mirror zoom system at the new aperture position.

[0051] Set any original position as the initial aperture position. When the aperture position changes, the primary aberration coefficient of the new aperture position can be directly obtained based on the primary aberration coefficient of the original aperture position. After the aperture position moves, the ray tracing process follows the following law:

[0052]

[0053] In the above formula, i,u,h are the angle between the first paraxial ray and the normal, the aperture angle and the incident height; i z ,u z ,h z are the angle between the second paraxial ray and the normal, the aperture angle and the incident height, the parameters with “*” represent the optical parameters of the new system after the aperture position is moved, and K is a parameter that characterizes the position of the new aperture relative to the original aperture, which is used as a reference for the aperture position movement in the present invention.

[0054] Based on this, the primary aberration coefficient at the new aperture position is expressed by the primary aberration coefficient of the system at the original aperture position:

[0055]

[0056] where ΣS I ,∑S II ,∑S III ,∑S IV ,∑S V They represent Seidel spherical aberration, coma, astigmatism, field curvature and distortion respectively. The parameters with "*" represent the optical parameters of the new system after the aperture position is moved. From this, the relationship between the aperture position and the primary aberration coefficient of the three-mirror zoom system is obtained.

[0057] According to the relationship between the aperture position and the primary aberration coefficient of the three-mirror zoom system, the change of the aberration coefficient when the aperture position changes can be calculated and evaluated, and then the appropriate aperture position can be selected according to the aberration index of the system design.

[0058] Step S1013: Analyze the diaphragm position for correcting the system aberration at the full focal length according to the change of the aberration coefficient of the three-mirror zoom system caused by the change of the diaphragm position.

[0059] According to the relationship between the aperture position and the primary aberration coefficient of the three-mirror zoom system in step S1012, it is obtained that, except for the system spherical aberration and field curvature, the coma, astigmatism and distortion of the new system after the aperture position is changed can be represented by the aperture position parameter K and the system primary aberration coefficient at the original aperture position, thereby calculating the aperture position parameter K in which the system coma, astigmatism and distortion are 0 respectively after the aperture position is moved, as follows:

[0060] When the system is coma-free, the aperture position parameter K satisfies:

[0061]

[0062] Based on this, the position of the coma-eliminating aperture at each focal length can be solved respectively.

[0063] When the system is free of astigmatism, the aperture position parameter K satisfies:

[0064]

[0065] Based on this, the position of the anastigmatism aperture at each focal length can be solved respectively.

[0066] When the system is dedistorted, the aperture position satisfies:

[0067] K 3 ∑S I +3K 2 ∑S II +K(3∑S III +∑S IV )+∑S V =0;

[0068] Based on this, the position of the distortion-eliminating aperture at each focal length can be solved respectively.

[0069] By comparing the current aperture position parameter K with the aperture position parameter K when the system eliminates coma, astigmatism and distortion, the difference can be used to evaluate the coma, astigmatism and distortion of the three-mirror zoom system at the current aperture position. The larger the difference, the worse the coma, astigmatism and distortion performance of the system at this aperture position; the smaller the difference, the better the performance. This indicates that the system has good coma, astigmatism and distortion performance at this aperture position. The aperture position parameter to eliminate coma, astigmatism or distortion, ε is the parameter index.

[0070] Step S1014: introducing an optimization function to analyze the aberration changes at each position of the full focal length when the aperture position changes, and obtaining the optimal aperture position of the three-mirror zoom system.

[0071] When the aperture position changes, the coma, astigmatism and distortion coefficients of the system also change differently at different focal lengths. For the entire three-mirror zoom system, the aperture positions for eliminating coma, astigmatism and distortion are different at different focal lengths. In order to achieve good performance of all aberrations in the full focal length of the system, an optimized objective function can be set according to the above analysis. The optimized objective function designed in this embodiment is as follows:

[0072]

[0073] The optimal aperture position K of the system at the full focal length can be calculated through the above optimization objective function, where w i (i=1,2,3...) are weight coefficients, and F1, F2, and F3 respectively represent the coma, astigmatism, and distortion objective functions of the system at full focal length. Thus, the present application has completed the system image quality analysis based on the change of the aperture position.

[0074] Preferably, Figure 5 As shown, the above step S102 may further include the following sub-steps:

[0075] Step S1021: using Zernike polynomials to fit the wavefront shape of the exit pupil in the three-mirror zoom system to obtain a wavefront expression.

[0076] The wavefront function is a mathematical function used to describe the phase distribution of the wavefront in space. It provides a quantitative way to represent the shape of the wavefront. Therefore, this step can fit the wavefront function at the exit pupil. The wavefront function can be represented by a high-order Zernike polynomial according to Taylor expansion as follows:

[0077]

[0078] Where Z i (ρ,θ) is a Zernike polynomial, q i are Zernike polynomial coefficients, and the waveform function at the system exit pupil wavefront can be obtained by using an appropriate fitting basis.

[0079] The wavefront function at the exit pupil of the three-mirror zoom system in this embodiment is fitted using high-order Zernike polynomials at short focus, long focus and full field of view, respectively, with subscripts W and T representing short focus and long focus, respectively, and j representing different fields of view, which can be characterized as follows:

[0080]

[0081] Step S1022: analyzing the fluctuation of the wavefront shape according to the wavefront expression obtained by fitting, and obtaining the change of the wavefront at the full focal length of the three-mirror zoom system relative to the reference wavefront.

[0082] According to the wavefront expression obtained by fitting, the wavefront peak and trough values ​​(PV values) and the mean square value (RMS value) of the wavefront as a whole can be analyzed and evaluated, and used as key indicators for evaluating the wavefront flatness and imaging stability of the system. When the wavefront shape at the exit pupil of the three-mirror zoom system meets the following indicators, it is considered that the three-mirror zoom system has good imaging quality and a relatively smooth wavefront:

[0083] PV<ξ,RMS<τ;

[0084] Among them, ξ and τ are indicators related to the design requirements of the three-mirror zoom system, which can be set according to different requirements of the system imaging quality. In this way, the evaluation of the oscillation of the wavefront shape at the exit pupil of the three-mirror zoom system is completed.

[0085] Preferably, Figure 6 As shown, the above step S103 may further include the following sub-steps:

[0086] Step S1031: combining the image quality analysis of the change in the aperture position with the wavefront change at the exit pupil of the three-mirror zoom system, to obtain the deformation of the wavefront as the aperture position changes when the light propagates in the free space.

[0087] The wavefront after the aperture position of the three-mirror zoom system is moved is analyzed, such as Figure 7 and Figure 8 As shown in the figure, when the aperture changes (the aperture position changes from the second element to the first element), the wavefront at the exit pupil also changes. In order to achieve a smooth wavefront and a better aberration coefficient, it is necessary to analyze the wavefront shape after the aperture position changes. The system wavefront change after the aperture position changes can be expressed by the following formula:

[0088]

[0089] In the above formula, Indicates that the wavefront shape changes with the aperture position, K is the aperture position parameter, ж=nu z y-nuy z is the Lagrange invariant of the system, is the gradient function of the wave aberration relative to the system aperture.

[0090] This can represent the wavefront function after the system aperture moves:

[0091]

[0092] According to the above calculation and the wavefront function of the full field of view and the full focal length obtained in steps S1021 and S1022, the change of the system wave aberration when the aperture position of the three-mirror zoom system moves to any position under the full field of view and the full focal length can be obtained. The PV and RMS evaluation method in step S1022 is still used to analyze the smoothness of the wavefront at the exit pupil after the change.

[0093] Step S1032: Based on the analysis of the deformation of the wavefront as the aperture position changes, the change of the wave aberration coefficient as the aperture position moves is given.

[0094] In this embodiment, according to the wavefront function of the three-mirror zoom system after the diaphragm is moved, the numerical relationship between the moving wave aberration and the change of the diaphragm position can be obtained. Taking the fourth-order wave aberration of the three-mirror zoom system as an example:

[0095]

[0096] Therefore, according to the expression of the system wave aberration after the aperture position is changed, the various aberration coefficients and imaging quality of the three-mirror zoom system after adjusting the aperture can be further evaluated.

[0097] Step S1033: Evaluate and analyze the wavefront shape of the movement of the aperture position to obtain image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths.

[0098] This step is to analyze the pupil position of the three-mirror zoom system in this embodiment after zooming at various focal lengths such as short focus and long focus. According to the wavefront oscillation and change of the wave aberration coefficient caused by the aperture position change introduced in steps S1031 and S1032, and according to the system design index requirements in this embodiment, a comparative analysis is performed with each wave aberration coefficient, so that a more complete evaluation of the imaging quality of the system can be achieved.

[0099] As can be seen from the above, the present invention analyzes the change of system aberration caused by the change of the stop position when the focal length is changed by introducing the relationship between the stop position and the aberration coefficient; in addition, the Zernike fitting polynomial is introduced to fit the wavefront shape of the system exit pupil, and the overall image quality of the system is evaluated by analyzing the oscillation of the wavefront shape; finally, on the basis of the change of the stop position and the change of the system wavefront, the wavefront deformation of the system caused by the stop is analyzed and calculated, providing a theoretical basis for the subsequent directional optimization design of the three-mirror zoom system.

[0100] like Fig. 9The figure shows a schematic diagram of the structure of a wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system provided by an embodiment of the present application, the device comprises: a first evaluation unit 910, a second evaluation unit 920 and a comprehensive evaluation unit 930, which are connected in sequence. Among them:

[0101] The first evaluation unit 910 is used to obtain the aberration change caused by the change of the pupil position during the zooming process based on the relationship between the primary aberration coefficient and the aperture position, and evaluate the optimal aperture position of the three-mirror zoom system according to the aberration change.

[0102] The second evaluation unit 920 is used to fit the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials, and evaluate the oscillation of the wavefront shape based on the fitting result.

[0103] The comprehensive evaluation unit 930 is used to analyze the pupil wavefront before and after the aperture position changes, calculate the wavefront deformation at the pupil caused by the aperture movement, and realize the full-focal-length image quality evaluation of the three-mirror zoom system.

[0104] Preferably, Fig.10 As shown, the first evaluation unit 910 may further include:

[0105] The system establishment module 911 is used to establish a three-mirror zoom system according to the Gauss bracket method and the system zoom relationship.

[0106] The aberration evaluation module 912 is used to set the initial aperture position, adjust the aperture position to analyze the influence of the aperture position change on the aberration coefficient of the three-mirror zoom system when the system zooms, and evaluate the aberration of the three-mirror zoom system under the new aperture position.

[0107] The aperture position analysis module 913 is used to analyze the aperture position for correcting the system aberration at the full focal length according to the change of the aberration coefficient of the three-mirror zoom system caused by the change of the aperture position.

[0108] The optimal aperture position acquisition module 914 is used to introduce an optimization function to analyze the aberration changes at each position of the full focal length when the aperture position changes, so as to obtain the optimal aperture position of the three-mirror zoom system.

[0109] Preferably, Fig.11 As shown, the second evaluation unit 920 may further include:

[0110] The fitting module 921 is used to fit the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials to obtain a wavefront expression.

[0111] The wavefront shape analysis module 922 is used to analyze the fluctuation of the wavefront shape according to the wavefront expression obtained by fitting, and obtain the change status of the wavefront at the full focal length of the three-mirror zoom system relative to the reference wavefront.

[0112] Preferably, Fig.12 As shown, the comprehensive evaluation unit 930 may further include:

[0113] The wavefront deformation acquisition module 931 is used to combine the image quality analysis of the aperture position change with the wavefront change at the exit pupil of the three-mirror zoom system to obtain the deformation of the wavefront caused by the change of the aperture position when the light propagates in the free space.

[0114] The aperture change acquisition module 932 is used to provide the change of the wave aberration coefficient with the movement of the aperture position based on the analysis of the deformation of the wavefront with the change of the aperture position.

[0115] The image quality analysis module 933 is used to evaluate and analyze the wavefront shape of the aperture position movement, and obtain the image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths.

[0116] For a detailed description of the above-mentioned units and modules, please refer to the corresponding description in the aforementioned method embodiment, which will not be repeated here.

[0117] It can be seen from the above technical scheme that the wavefront joint quantitative distribution analysis and image quality evaluation device of the three-mirror zoom system provided by the present invention can realize the analysis of the wavefront shape at the exit pupil of the three-mirror system with variable focal length at all focal lengths and the analysis of the aberration coefficient and wavefront change caused by the pupil change, providing a theoretical basis for the subsequent directional optimization design of the optical system. Specifically, the present invention analyzes the system aberration change caused by the change of the diaphragm position when the focal length is changed by introducing the relationship between the diaphragm position and the aberration coefficient; in addition, the Zernike fitting polynomial is introduced to fit the wavefront shape of the system exit pupil, and the overall image quality of the system is evaluated by analyzing the oscillation of the wavefront shape; finally, based on the change of the diaphragm position and the change of the system wavefront, the wavefront deformation of the system caused by the diaphragm is analyzed and calculated, providing a theoretical basis for the subsequent directional optimization design of the three-mirror zoom system.

[0118] An embodiment of the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the above method is implemented when the processor executes the program.

[0119] An embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program for executing the above method.

[0120] like Fig.13As shown, the electronic device 600 may further include: a communication module 110, an input unit 120, an audio processor 130, a display 160, and a power supply 170. It is worth noting that the electronic device 600 does not necessarily have to include Fig.13 In addition, the electronic device 600 may also include Fig.13 For components not shown, reference may be made to the prior art.

[0121] like Fig.13 As shown, the central processor 100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor devices and / or logic devices. The central processor 100 receives inputs and controls the operations of various components of the electronic device 600.

[0122] The memory 140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 100 may execute the program stored in the memory 140 to implement information storage or processing.

[0123] The input unit 120 provides input to the CPU 100. The input unit 120 is, for example, a key or a touch input device. The power supply 170 is used to provide power to the electronic device 600. The display 160 is used to display display objects such as images and text. The display may be, for example, an LCD display, but is not limited thereto.

[0124] The memory 140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 140 may also be some other type of device. The memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 may include an application / function storage unit 142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 600 through the central processor 100.

[0125] The memory 140 may also include a data storage unit 143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 144 of the memory 140 may include various drivers for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0126] The communication module 110 is a transmitter / receiver that transmits and receives signals via the antenna 111. The communication module 110 (transmitter / receiver) is coupled to the central processor 100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

[0127] Based on different communication technologies, multiple communication modules 110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and / or a wireless LAN module. The communication module 110 (transmitter / receiver) is also coupled to a speaker 131 and a microphone 132 via an audio processor 130 to provide an audio output via the speaker 131 and receive an audio input from the microphone 132, thereby realizing a common telecommunication function. The audio processor 130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 130 is also coupled to the central processor 100, so that recording can be performed on the local machine through the microphone 132, and the sound stored on the local machine can be played through the speaker 131.

[0128] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0129] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A wavefront joint quantitative distribution analysis and image quality evaluation method for a three-mirror zoom system, characterized in that: The method comprises: Acquire the aberration change caused by the change of pupil position during zooming based on the relationship between the primary aberration coefficient and the aperture position, and evaluate the optimal aperture position of the three-mirror zoom system according to the aberration change; Using Zernike polynomials to fit the wavefront shape of the exit pupil in the three-mirror zoom system, and evaluating the oscillation of the wavefront shape based on the fitting result; The pupil wavefront before and after the aperture position changes is analyzed, and the wavefront deformation at the pupil caused by the aperture movement is calculated to achieve full-focal-length image quality evaluation of the three-mirror zoom system.

2. The wavefront joint quantitative distribution analysis and image quality evaluation method of the three-mirror zoom system according to claim 1, characterized in that: The method of obtaining the aberration change caused by the change of the pupil position during zooming based on the relationship between the primary aberration coefficient and the aperture position, and evaluating the optimal aperture position of the three-mirror zoom system according to the aberration change comprises: A three-mirror zoom system is established based on the Gauss bracket method and the system magnification relationship; Set the initial aperture position, adjust the aperture position to analyze the effect of the aperture position change on the aberration coefficient of the three-mirror zoom system when the system zooms, and evaluate the aberration of the three-mirror zoom system under the new aperture position; According to the change of the aberration coefficient of the three-mirror zoom system caused by the change of the aperture position, the aperture position for correcting the system aberration at the full focal length is analyzed; An optimization function is introduced to analyze the aberration changes at each position of the full focal length when the aperture position changes, and the optimal aperture position of the three-mirror zoom system is obtained.

3. The wavefront joint quantitative distribution analysis and image quality evaluation method of the three-mirror zoom system according to claim 1, characterized in that: The step of fitting the wavefront shape of the exit pupil of the three-mirror zoom system by using Zernike polynomials, and evaluating the oscillation of the wavefront shape based on the fitting result includes: The wavefront shape of the exit pupil in the three-mirror zoom system is fitted using Zernike polynomials to obtain the wavefront expression. According to the wavefront expression obtained by fitting, the fluctuation of the wavefront shape is analyzed to obtain the change of the wavefront relative to the reference wavefront at the full focal length of the three-mirror zoom system.

4. The wavefront joint quantitative distribution analysis and image quality evaluation method of the three-mirror zoom system according to claim 1, characterized in that: The analyzing of pupil wavefronts before and after the aperture position changes, calculating the wavefront deformation at the pupil caused by the aperture movement, and realizing the full-focal-length image quality evaluation of the three-mirror zoom system includes: By combining the image quality analysis of the change of the aperture position with the wavefront change at the exit pupil of the three-mirror zoom system, the deformation of the wavefront as the aperture position changes when the light propagates in free space is obtained; Based on the analysis of the deformation of wavefront with the change of aperture position, the change of wave aberration coefficient with the movement of aperture position is given; The wavefront shape of the moving aperture position is evaluated and analyzed, and the image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths is obtained.

5. A wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system, characterized in that: The device comprises: A first evaluation unit is used to obtain an aberration change caused by a change in pupil position during zooming based on a relationship between a primary aberration coefficient and an aperture position, and to evaluate an optimal aperture position of the three-mirror zoom system according to the aberration change; A second evaluation unit is used to fit the wavefront shape of the exit pupil in the three-mirror zoom system using Zernike polynomials, and evaluate the oscillation of the wavefront shape based on the fitting result; The comprehensive evaluation unit is used to analyze the pupil wavefront before and after the aperture position changes, calculate the wavefront deformation at the pupil caused by the aperture movement, and realize the full-focal-length image quality evaluation of the three-mirror zoom system.

6. The wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system according to claim 5, characterized in that: The first evaluation unit comprises: System establishment module, used to establish a three-mirror zoom system based on Gauss bracket method and system zoom relationship; An aberration evaluation module is used to set the initial aperture position, adjust the aperture position to analyze the influence of the aperture position change on the aberration coefficient of the three-mirror zoom system when the system is zoomed, and evaluate the aberration of the three-mirror zoom system under the new aperture position; An aperture position analysis module is used to analyze the aperture position for correcting the system aberration at the full focal length according to the change of the aberration coefficient of the three-mirror zoom system caused by the change of the aperture position; The optimal aperture position acquisition module is used to introduce an optimization function to analyze the aberration changes at each position of the full focal length when the aperture position changes, and obtain the optimal aperture position of the three-mirror zoom system.

7. The wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system according to claim 5, characterized in that: The second evaluation unit comprises: A fitting module, used for fitting the wave surface shape of the exit pupil in the three-mirror zoom system using Zernike polynomials to obtain a wave surface expression; The wavefront shape analysis module is used to analyze the fluctuation of the wavefront shape according to the wavefront expression obtained by fitting, and obtain the change status of the wavefront at the full focal length of the three-mirror zoom system relative to the reference wavefront.

8. The wavefront joint quantitative distribution analysis and image quality evaluation device for a three-mirror zoom system according to claim 5, characterized in that: The comprehensive assessment unit includes: The wavefront deformation acquisition module is used to combine the image quality analysis of the change of the aperture position with the wavefront change at the exit pupil of the three-mirror zoom system to obtain the deformation of the wavefront as the aperture position changes when the light propagates in free space; An aperture change acquisition module is used to provide the change of the wave aberration coefficient as the aperture position moves based on the analysis of the deformation of the wavefront as the aperture position changes; The image quality analysis module is used to evaluate and analyze the wavefront shape of the movement of the aperture position, and obtain the image quality analysis of the three-mirror zoom system when the pupil position changes at different focal lengths.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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