Inclined random phase shift phase demodulation method and device and electronic equipment

Abstract

The invention provides an inclined random phase shift phase demodulation method and device and electronic equipment, and relates to the technical field of interference-based optical detection, and the method comprises the steps: carrying out the collection through an interferometer according to a set step length, obtaining four first interferograms, carrying out the background removal of the first interferograms through setting the step length as # imgabs0 #, and obtaining a second interferogram; obtaining a first signal according to the second interferogram, wherein the first signal comprises light intensity; performing tilt information extraction on the second interferogram to obtain a second signal, the second signal comprising a carrier frequency; performing de-tilt processing on the second interferogram according to the second signal to obtain a de-tilt third interferogram; obtaining a third signal according to the third interferogram, wherein the third signal comprises the light intensity of the third interferogram; and obtaining a to-be-measured phase according to the third signal. According to the design, the accurate inclination information is obtained by directly performing mathematical transformation and spectral analysis on the interference pattern; and the method does not depend on specific initial conditions or iteration parameters, and is more universal.

Description

Technical Field

[0001] The present application relates to the technical field of optical detection based on interference. Specifically, it relates to a method, device and electronic device for demodulating the phase of inclined random phase shift. Background Art

[0002] In optical interferometric measurement, due to factors such as environmental vibration and instrument error, random tilt errors may occur during the phase shift process of the interferometer. Such errors will directly affect the extraction of the phase information of the interference pattern, and further affect the accuracy of the measurement results. Currently, the phase information is often demodulated by the iterative method. In phase shift phase demodulation, the iterative method is usually used to process signals containing complex phase information, such as interference patterns, modulation signals, etc.

[0003] However, there are some problems in the use of the iterative method. First of all, the calculation speed of the iterative method is relatively slow. Especially when dealing with large-scale data or complex problems, it is necessary to repeatedly execute calculation steps to gradually approach the target result. Secondly, the convergence of the iterative method is not always certain, and it is affected by various factors such as the choice of iterative formula, the setting of the initial value, and the nature of the problem. In addition, the iterative method is prone to falling into local optimal solutions, especially in optimization problems, which limits its application in scenarios where a global optimal solution is required. At the same time, when dealing with large-scale data sets, the iterative method also consumes a large amount of computing resources and storage space. Finally, the precision control of the iterative method also has a certain degree of difficulty, and parameters such as the number of iterations and error limits need to be accurately set to ensure the accuracy of the solution, and the selection of these parameters often depends on the specific nature of the problem and experience. Summary of the Invention

[0004] In order to at least overcome the above deficiencies in the prior art, the purpose of the present application is to provide a method, device and electronic device for demodulating the phase of inclined random phase shift.

[0005] In a first aspect, an embodiment of the present application provides a method for demodulating the phase of inclined random phase shift, the method comprising:

[0006] Acquire four first interference patterns by an interferometer according to a set step size, the set step size being

[0007] Perform background removal processing on the first interference pattern to obtain a second interference pattern; obtain a first signal according to the second interference pattern, the first signal including light intensity;

[0008] Extract tilt information from the second interference pattern to obtain a second signal, the second signal including carrier frequency;

[0009] Deslant the second interferogram according to the second signal to obtain a deslanted third interferogram; obtain a third signal according to the third interferogram, where the third signal includes the light intensity of the third interferogram;

[0010] Obtain the phase to be measured according to the third signal.

[0011] In a possible implementation, the method for deslanting the first interferogram to obtain the second interferogram includes:

[0012] Apply image processing technology to the first interferogram to obtain the second interferogram with the background removed.

[0013] In a possible implementation, the expression of the first signal or the third signal includes:

[0014]

[0015] where I i is the light intensity of the i-th currently processed interferogram, the currently processed interferogram includes the second interferogram or the third interferogram, i is the serial number of the currently processed interferogram, b is the modulation degree, f i is the carrier frequency of the i-th currently processed interferogram, is the phase, δ i is the phase shift amount, and (x, y) is the specific position in the currently processed interferogram.

[0016] In a possible implementation, the method for calculating the phase shift amount is:

[0017]

[0018] where δ i is the phase shift amount of the i-th currently processed interferogram.

[0019] In a possible implementation, the method for extracting tilt information from the second interferogram to obtain the second signal includes:

[0020] Perform zero-padding on the second interferogram;

[0021] Perform a two-dimensional discrete Fourier transform on the zero-padded image;

[0022] Determine the position of the first-order spectrum center;

[0023] Obtain the second signal according to the position of the first-order spectrum center.

[0024] In a possible implementation, the method for extracting tilt information from the second interferogram to obtain the second signal further includes:

[0025] Perform preprocessing operations such as filtering and enhancing the contrast on the second interference image;

[0026] Use an image processing algorithm to identify the interference fringes in the second interference image;

[0027] Measure the distance between adjacent interference fringes;

[0028] Obtain a second signal based on the distance between adjacent interference fringes.

[0029] In a possible implementation, the method for de - tilting the second interference image according to the second signal to obtain a de - tilted third interference image includes:

[0030]

[0031] Where I j is the light intensity of the j - th second interference image, I j+1 is the light intensity of the (j + 1)-th second interference image, f j is the carrier frequency of the j - th second interference image, f j+1 is the carrier frequency of the (j + 1)-th second interference image;

[0032] Where I 5 = I 1 .

[0033] In a possible implementation, the method for obtaining the phase to be measured according to the third signal includes:

[0034]

[0035] Where is the phase and I is the light intensity.

[0036] In a second aspect, an embodiment of the present application further provides a tilt - random phase - shifting phase demodulation device, and the device includes:

[0037] An acquisition module: Acquire four first interference images according to a set step size through an interferometer, and the set step size is

[0038] A first image processing module: Used to perform background removal on the first interference image to obtain a second interference image; obtain a first signal according to the second interference image, and the first signal includes light intensity;

[0039] An information extraction module: Used to extract tilt information from the second interference image to obtain a second signal, and the second signal includes a carrier frequency;

[0040] The second image processing module: configured to perform a de-tilting process on the second interference pattern according to the second signal to obtain a de-tilted third interference pattern; obtain a third signal according to the third interference pattern, where the third signal includes the light intensity of the third interference pattern.

[0041] The data processing module: configured to obtain the phase to be measured according to the third signal.

[0042] In a third aspect, an embodiment of the present application further provides an electronic device, which includes a machine-readable storage medium and a processor. The machine-readable storage medium stores machine-executable instructions, and when the machine-executable instructions are executed by the processor, the method for demodulating the phase of the tilt random phase shift according to any one of claims 1-8 is implemented.

[0043] Based on any of the above aspects, the method, device, and electronic device for demodulating the phase of the tilt random phase shift provided by the embodiments of the present application directly perform mathematical transformation and spectral analysis on the interference pattern, quickly and accurately locate and quantify the tilt information, and do not need to go through the multiple iterative approximation processes required by the iterative method, significantly improving the processing speed and efficiency. In addition, this method does not depend on the selection of specific initial conditions or iterative parameters, can maintain stable performance in different application scenarios, and has stronger adaptability and flexibility. Compared with the traditional iterative method, this design has directness and high efficiency. Description of the Drawings

[0044] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be referred to in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0045] Figure 1 It is a schematic flowchart of the method for demodulating the phase of the tilt random phase shift provided by the embodiment of the present application;

[0046] Figure 2 It is one of the schematic diagrams of the sub-steps of step S300 provided by the embodiment of the present application;

[0047] Figure 3 It is another schematic diagram of the sub-steps of step S300 provided by the embodiment of the present application;

[0048] Figure 4 It is a schematic structural diagram of the device for demodulating the phase of the tilt random phase shift provided by the embodiment of the present application;

[0049] Figure 5 It is a schematic structural diagram of the electronic device provided by the embodiment of the present application.

[0050] Icons: 800 - Electronic device; 810 - Processor; 820 - Machine - readable storage medium; 830 - Oblique random phase - shifting phase demodulation device; 831 - Acquisition module; 832 - First image - processing module; 833 - Information extraction module; 834 - Second image - processing module; 833 - Data - processing module. Detailed implementation manners

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application described and illustrated herein generally can be arranged and designed in a variety of different configurations.

[0052] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0053] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0054] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use. It is only for the convenience of describing the present application 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 thus should not be construed as a limitation of the present application. In addition, terms such as "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0055] It should be noted that, without conflict, different features in the embodiments of the present application can be combined with each other.

[0056] The following will describe in detail the specific implementation manners of the present application with reference to the accompanying drawings.

[0057] Please refer to Figure 1 , the present application provides an oblique random phase - shifting phase demodulation method, and the method may include the following steps:

[0058] Step S100: Four first interference patterns are acquired by an interferometer according to a set step size, and the set step size is

[0059] In this embodiment, first, the phase-stepping interferometry technique is used. By controlling a certain element in the interferometer to adjust the position of the mirror, such as a piezoelectric ceramic actuator, the optical path difference between the reference light and the test light is changed, thereby generating different phase differences. The amount of change each time is preset, which is That is, at each acquisition, the phase difference increases by By continuously acquiring four times, a complete phase cycle can be covered, thereby capturing the entire process of the interference pattern changing with the phase and obtaining four first interference patterns.

[0060] Step S200: Perform background removal processing on the first interference pattern to obtain a second interference pattern; obtain a first signal according to the second interference pattern, and the first signal includes light intensity;

[0061] The background part of the first interference pattern obtained through step S100 contains a lot of information irrelevant to the main measurement target, such as light source non-uniformity, device noise, ambient light interference, etc. These background information will be superimposed on the interference pattern, resulting in a complex light intensity distribution and making it difficult to directly extract useful phase or shape information.

[0062] Therefore, in this embodiment, through background removal processing, the interference pattern becomes clearer and purer, enabling more accurate extraction of the phase or other relevant parameters of the measured object during subsequent image processing and data analysis.

[0063] Step S300: Extract tilt information from the second interference pattern to obtain a second signal, and the second signal includes carrier frequency;

[0064] The light intensity distribution of the second interference pattern obtained through step S200 is mainly determined by the carrier frequency and phase information. In phase-shifting interferometry, tilt usually appears as the wave loaded in the interference pattern. In order to extract the phase information of the measured object, in this embodiment, the carrier frequency is extracted from the second interference pattern.

[0065] Step S400: Perform de-tilting processing on the second interference pattern according to the second signal to obtain a third interference pattern after de-tilting; obtain a third signal according to the third interference pattern, and the third signal includes the light intensity of the third interference pattern;

[0066] In this embodiment, the information of the carrier frequency is used to correct the tilt of the third interference pattern. The carrier frequency provides the spatial frequency information of the interference fringes. Through this information, it can be determined how the fringes in the third interference pattern are tilted, and the corresponding mathematical transformation is applied to make the fringes horizontal, so that the third interference pattern can be analyzed more accurately, and then the phase information of the object to be measured can be solved according to the third signal obtained from the third interference pattern.

[0067] Step S500: Obtain the phase to be measured according to the third signal.

[0068] In this embodiment, four-step phase shifting is used to solve for the phase to obtain the phase information of the object under test. The third interferogram after deskewing is obtained through step 400, and then the third signal is obtained. Therefore, the phase can be obtained according to the third signal in this step.

[0069] During the manufacturing process of optical elements, such as lenses, mirrors, prisms, etc., minute deformations, surface roughness, or unevenness can significantly affect their performance. This method utilizes the interference phenomenon of light by generating two or more coherent light waves to form an interference pattern on the surface of the optical element. These interference patterns contain information about the surface topography of the element. By moving the optical element or changing a certain element in the optical path, such as a phase modulator, random tilt of the phase can be achieved, and then the three-dimensional topography of the element surface can be restored through a demodulation algorithm.

[0070] In addition, this method is also widely applied in fields such as phase modulation and demodulation, signal processing and analysis in the communication field.

[0071] Compared with using the iterative method for random tilt phase shifting phase demodulation, this method directly performs mathematical transformation and spectral analysis on the interferogram, quickly and accurately locates and quantifies the tilt information, without going through the multiple iterative approximation processes required by the iterative method, significantly improving the processing speed and efficiency. In addition, this method does not depend on the selection of specific initial conditions or iterative parameters, can maintain stable performance in different application scenarios, and has stronger adaptability and flexibility.

[0072] In a possible implementation manner, the method for performing background removal on the first interferogram in step S200 to obtain the second interferogram includes:

[0073] Image processing technology acts on the first interferogram to obtain the second interferogram after background removal.

[0074] In this embodiment, image processing technology can be used to remove the background from the first interferogram. The operator needs to manually select and mark the background area, and then use the algorithm of the software to remove these areas. The advantage of this method is intuitive and flexible, and the operator can make fine adjustments to the background according to the actual situation.

[0075] It should be noted that there are various methods for removing the background from the first interferogram, such as various automatic background removal methods based on mathematical algorithms. These methods usually utilize the statistical characteristics or spatial structure of the interferogram to distinguish the interference fringes and background information. Different methods are applicable to different interference measurement scenarios and specific requirements.

[0076] In a possible implementation, the first signal or the third signal expression includes:

[0077]

[0078] where I i is the light intensity of the i-th currently processed interference pattern, the currently processed interference pattern includes the second interference pattern or the third interference pattern, i is the serial number of the currently processed interference pattern, b is the modulation degree, f i is the carrier frequency of the i-th currently processed interference pattern, is the phase, δ i is the phase shift amount, and (x, y) is the specific position in the currently processed interference pattern.

[0079] In this embodiment, the information on the interference pattern can be expressed by the above formula. When obtaining the first signal, the second interference pattern is currently being processed; when obtaining the third signal, the third interference pattern is currently being processed. For example, the light intensity distribution of the second interference pattern mainly includes carrier frequency and phase information. Therefore, in order to obtain the phase information of the object under test, the carrier frequency needs to be obtained.

[0080] In a possible implementation, in a possible implementation manner, the method for calculating the phase shift amount is:

[0081]

[0082] where δ i is the phase shift amount of the i-th currently processed interference pattern.

[0083] In interference pattern measurement, the phase shift amount is usually introduced by moving a certain element in the interferometer, such as a mirror, to obtain multiple interference patterns with different phase differences.

[0084] In phase-shifting interferometry, tilt usually appears as a wave loaded in the interference pattern, and this wave is actually a modulation of the phase. In order to accurately extract this tilt information, the carrier parameters need to be obtained.

[0085] In a possible implementation, please refer to Figure 2 , the step S300 may include the following sub-steps:

[0086] Step S311: Perform zero-padding operation on the second interference pattern.

[0087] In this embodiment, in order to more accurately locate the features in the spectrum, especially the position of the carrier, when performing a two-dimensional discrete Fourier transform (DFT), this embodiment performs a zero-padding operation on the first interferogram to obtain a fourth interferogram. The zero-padding operation is achieved by adding zero-valued pixels around the boundary of the first interferogram, thereby increasing the total size of the first interferogram. This does not change the information content of the first interferogram, but can improve the resolution of the spectrum in the frequency domain, making the spectral features clearer.

[0088] Step S312: Perform a two-dimensional discrete Fourier transform on the zero-padded image.

[0089] In this embodiment, the fourth interferogram is subjected to DFT to transform it from the spatial domain to the frequency domain. In the frequency domain, the spectral characteristics of the fourth interferogram are revealed. The result of the DFT is a complex matrix that contains the frequency information of the image.

[0090] Step S313: Determine the position of the center of its first-order spectrum.

[0091] In the frequency domain, the carrier usually appears as one or more distinct peaks in the spectrum, and these peaks correspond to the tilt information in the fourth interferogram. In this embodiment, by finding and determining the center positions of these peaks (i.e., the first-order spectrum), the specific parameters of the carrier can be obtained. When performing this step, it is usually necessary to perform visual analysis on the spectral image and use spectral analysis tools in image processing software or programming tools to accurately measure the positions of the peaks.

[0092] Step S314: Obtain the second signal according to the position of the center of the first-order spectrum.

[0093] In this embodiment, the second signal is the magnitude of the carrier. The center position of the first-order spectrum not only reveals the direction of the carrier, i.e., the tilt angle, but also directly reflects the magnitude of the carrier, i.e., its frequency or wavelength. The magnitude of the carrier is an important parameter in the tilt information, which determines the degree of modulation of the tilt on the phase distribution. By measuring the distance between the center position of the first-order spectrum and the center of the spectral diagram in the frequency domain, we can calculate the specific magnitude of the carrier, and then perform a de-tilting process on the second interferogram to eliminate the influence of the tilt on the phase calculation.

[0094] In another possible implementation, please refer to Figure 3 , the step S300 may further include the following sub-steps:

[0095] Step S321: Perform preprocessing operations such as filtering and enhancing the contrast on the second interferogram image.

[0096] In this embodiment, by performing preprocessing operations such as filtering and enhancing the contrast on the interference image, the interference fringes can be seen more clearly.

[0097] Step S322: Use an image processing algorithm to identify the interference fringes in the second interference image.

[0098] In this embodiment, the image processing algorithm includes algorithms such as edge detection and Hough transform.

[0099] Step S323: Measure the distance between adjacent interference fringes.

[0100] Step S324: Obtain a second signal based on the distance between adjacent interference fringes.

[0101] Since the carrier frequency is inversely proportional to the fringe spacing, and its specific relationship depends on the geometric configuration and physical parameters of the interference system, in this embodiment, a second signal can be obtained based on the distance between adjacent interference fringes.

[0102] It should be noted that implementing step S200 includes not only the above methods, but also a variety of different methods, such as Phase Unwrapping, Phase Shifting Interferometry (PSI), etc. Different methods are applicable to different interference measurement scenarios and specific requirements.

[0103] In a possible implementation manner, the method for performing a de-tilting process on the second interference pattern according to the second signal in step S400 to obtain a de-tilted third interference pattern includes:

[0104]

[0105] where I j is the light intensity of the j-th second interference pattern, I j+1 is the light intensity of the (j + 1)-th second interference pattern, f j is the carrier frequency of the j-th second interference pattern, f j+1 is the carrier frequency of the (j + 1)-th second interference pattern;

[0106] where I 5 = I 1 .

[0107] Since the phase step size in this embodiment is so the two adjacent interference patterns can be regarded as orthogonal signals. There is the following formula

[0108]

[0109] where b is the modulation degree, f is the carrier, is the phase.

[0110] It shows that when there is a carrier wave with a frequency of f modulated on the phase when, if the modulation signal is multiplied by the carrier signal and through appropriate processing, we can perform a deskewing process on the interference pattern.

[0111] Therefore, in this embodiment, use:

[0112]

[0113] Perform a deskewing process on the second interference pattern to obtain a third interference pattern, and obtain a third signal according to the third interference pattern.

[0114] In a possible implementation manner, the step S500 includes:

[0115]

[0116] where is the phase and I is the light intensity.

[0117] In this embodiment, the four-step phase shifting method is used to solve for the phase. Substitute the obtained third signal into the above formula to obtain the phase information of the object under test.

[0118] Please refer to Figure 4 , this application also provides a tilt random phase shifting phase demodulation device 830. The tilt random phase shifting phase demodulation device 830 includes a plurality of functional modules that can be stored in a machine-readable storage medium 820 in software form. Functionally divided, the tilt random phase shifting phase demodulation device 830 can include an acquisition module 831, a first image processing module 832, an information extraction module 833, a second image processing module 834, and a data processing module 835. Among them:

[0119] The acquisition module 831 is used to acquire four first interference patterns through an interferometer according to a set step size, and the set step size is

[0120] In this embodiment, the acquisition module 831 can be used to execute Figure 1 the step S100 shown. For the specific description of the acquisition module 831, reference can be made to the description of step S100.

[0121] The first image processing module 832 is used to perform background removal processing on the first interference pattern to obtain a second interference pattern; obtain a first signal according to the second interference pattern, and the first signal includes light intensity;

[0122] In this embodiment, the first image processing module 832 can be used to execute Figure 1For the detailed description of step S200 , please refer to the description of step S200 for the first image processing module 832 .

[0123] The information extraction module 833 is used to extract tilt information from the second interference pattern to obtain a second signal, where the second signal includes a carrier frequency;

[0124] In this embodiment, the information extraction module 833 can be used to perform Figure 1 As shown in step S300 , for a detailed description of the information extraction module 833 , reference may be made to the description of step S300 .

[0125] The second image processing module 834 is used to perform a de-tilting process on the second interference pattern according to the second signal to obtain a de-tilted third interference pattern; obtain a third signal according to the third interference pattern, wherein the third signal includes the light intensity of the third interference pattern;

[0126] In this embodiment, the second image processing module 834 may be used to perform Figure 1 As shown in step S400 , for a detailed description of the second image processing module 834 , reference may be made to the description of step S400 .

[0127] The data processing module 835 is used to obtain the phase to be measured according to the third signal.

[0128] In this embodiment, the data processing module 835 can be used to perform Figure 1 For the detailed description of the data processing module 835 , please refer to the description of step S500 .

[0129] The present application also provides an electronic device 800, please refer to Figure 5 , Figure 5 Block diagram of an example electronic device 800. The electronic device 800 includes a processor 810, a machine-readable storage medium 820, and a tilted random phase shift phase demodulation device 830. The machine-readable storage medium 820 and the processor 810 are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The tilted random phase shift phase demodulation device 830 includes a plurality of software function modules that can be stored in the machine-readable storage medium 820 in the form of software or firmware or solidified in the operating system (OS) of the tilted random phase shift phase demodulation device 830. The processor 810 is used to execute executable modules stored in the machine-readable storage medium 820, such as software function modules and computer programs included in the tilted random phase shift phase demodulation device 830.

[0130] Among them, the machine-readable storage medium 820 can be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc. Among them, the machine-readable storage medium 820 is used to store a program, and after receiving an execution instruction, the processor 810 executes the program.

[0131] The processor 810 may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor 810 may be a general-purpose processor 810, including a central processing unit 810 (CPU for short), a network processor 810 (NP for short), etc.; it may also be a digital signal processor 810 (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor 810 may be a microprocessor 810 or the processor 810 may also be any conventional processor 810, etc.

[0132] In summary, the present application provides a tilt random phase-shifting phase demodulation method, device, and electronic device, which relate to the field of optical detection technology based on interference. The method includes: collecting four first interference patterns through an interferometer according to a set step size, and the set step size is Performing background removal processing on the first interference pattern to obtain a second interference pattern; obtaining a first signal according to the second interference pattern, where the first signal includes light intensity; extracting tilt information from the second interference pattern to obtain a second signal, where the second signal includes a carrier frequency; performing tilt removal processing on the second interference pattern according to the second signal to obtain a third interference pattern after tilt removal; obtaining a third signal according to the third interference pattern, where the third signal includes the light intensity of the third interference pattern; obtaining the phase to be measured according to the third signal. The above design can accurately determine the tilt information by directly performing mathematical transformation and spectral analysis on the interference pattern; and it does not depend on the selection of specific initial conditions or iterative parameters, and is more general.

[0133] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0134] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A tilted random phase shift phase demodulation method, characterized in that: The method comprises: Four first interference patterns are obtained by collecting with an interferometer according to a set step length, wherein the set step length is Performing background removal processing on the first interference pattern to obtain a second interference pattern; obtaining a first signal according to the second interference pattern, wherein the first signal includes light intensity; Extracting tilt information from the second interference pattern to obtain a second signal, where the second signal includes a carrier frequency; Performing a de-tilting process on the second interference pattern according to the second signal to obtain a de-tilted third interference pattern; obtaining a third signal according to the third interference pattern, wherein the third signal includes the light intensity of the third interference pattern; A phase to be measured is obtained according to the third signal.

2. The method according to claim 1, characterized in that The method of performing background removal processing on the first interference pattern to obtain the second interference pattern comprises: Image processing technology is applied to the first interference map to obtain the second interference map after the background is removed.

3. The method according to claim 1, characterized in that The first signal or the third signal expression includes: Among them, I i is the light intensity of the i-th interference pattern currently being processed, the interference pattern currently being processed includes the second interference pattern or the third interference pattern, i is the sequence number of the interference pattern currently being processed, b is the modulation degree, and f i is the carrier frequency of the i-th interferogram currently processed, is the phase, δ i is the phase shift, and (x, y) is the specific position in the interference pattern currently being processed.

4. The method according to claim 3, characterized in that The phase shift calculation method is: where δ i is the phase shift of the i-th interference pattern currently being processed.

5. The method according to claim 1, characterized in that The method of extracting tilt information from the second interference pattern to obtain a second signal includes: performing a zero-padding operation on the second interference pattern; Perform a two-dimensional discrete Fourier transform on the zero-padded image; Determine the center position of its primary spectrum; The second signal is obtained according to the center position of the primary spectrum.

6. The method according to claim 1, characterized in that The method of extracting tilt information from the second interference pattern to obtain a second signal further includes: Performing preprocessing operations such as filtering and contrast enhancement on the second interference image; identifying interference fringes in the second interference image using an image processing algorithm; Measure the distance between adjacent interference fringes; A second signal is obtained according to the distance between adjacent interference fringes.

7. A tilted random phase shift phase demodulation method according to claim 1, characterized in that: The method of performing a de-tilting process on the second interference graph according to the second signal to obtain a de-tilted third interference graph comprises: Among them I j is the light intensity of the jth interference pattern of the second image, I j+1 is the light intensity of the j+1th interference pattern of the second image, f j is the carrier frequency of the jth second interference pattern, f j+1 is the carrier frequency of the j+1th second interference pattern; Among them, I5=I1.

8. The method according to claim 1, characterized in that The method for obtaining the phase to be measured according to the third signal comprises: in is the phase and I is the light intensity.

9. A tilted random phase shift phase demodulation device, characterized in that: The device comprises: Acquisition module: four first interference patterns are acquired by interferometer according to the set step length, and the set step length is A first image processing module: used for performing background removal processing on the first interference pattern to obtain a second interference pattern; and obtaining a first signal according to the second interference pattern, wherein the first signal includes light intensity; An information extraction module is used to extract tilt information from the second interference pattern to obtain a second signal, where the second signal includes a carrier frequency; A second image processing module is used to perform a de-tilting process on the second interference pattern according to the second signal to obtain a de-tilted third interference pattern; and obtain a third signal according to the third interference pattern, wherein the third signal includes the light intensity of the third interference pattern; Data processing module: used to obtain the phase to be measured according to the third signal.

10. An electronic device, characterized in that: It comprises a machine-readable storage medium and a processor, wherein the machine-readable storage medium stores machine-executable instructions, and when the machine-executable instructions are executed by the processor, the inclined random phase shift phase demodulation method according to any one of claims 1 to 8 is implemented.

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