CN110514137A - Phase unwrapping method, device, system, computer equipment and storage medium - Google Patents

Abstract

The invention discloses a phase unwrapping method, device, system, computer equipment and storage medium. The method includes: acquiring a wrapped phase interferogram; determining a threshold; determining the concave boundary of the wrapped phase interferogram through the threshold to form a flipping critical line ; Automatically flip and replace the concave part of the wrapped phase interferogram to obtain the first unwrapped phase matrix; filter and smooth the first unwrapped phase matrix to obtain the second unwrapped phase matrix; calculate and save the first unwrapped phase The relative error between the matrix and the second unwrapped phase matrix; when the threshold does not reach the preset value, return to re-determine the threshold and perform subsequent operations; when the threshold reaches the preset value, output the threshold corresponding to the minimum relative error and the second unwrapped Phase matrix; output the reconstructed true phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error. The invention improves the efficiency and accuracy of the real phase restoration of the wrapped phase interferogram.

Description

Phase unwrapping method, device, system, computer equipment and storage medium

technical field

The invention relates to a phase unwrapping method, device, system, computer equipment and storage medium, belonging to the field of image processing research.

Background technique

Phase unwrapping calculation is widely used in interferometric synthetic aperture radar, three-dimensional measurement based on structured light, optical interferometry and imaging and other measurement methods. In the process of obtaining the phase from the wrapped interferogram, it is generally necessary to use the arctangent norm to extract the phase, so that the continuous phase is truncated, and the value range is limited to (-π, π], forming a wrapped phase diagram. Therefore, it is necessary to analyze the wrapped phase Perform unwrapping and reconstruct the truncated phase to obtain the real continuous phase. However, in actual situations, due to factors such as undersampling, noise, and local shadows, residual point areas often appear in the wrapped phase, which affects the accuracy of unwrapping. It increases the difficulty of unwrapping and indirectly affects the accuracy of real phase reconstruction.

There are many existing phase unwrapping algorithms and methods, and they can be summarized into two types: path-following algorithm and path-independent algorithm. Among them, path-tracking algorithms mainly include branch-cut method, quality map-oriented method, mask secant method, etc.; path-independent algorithm mainly seeks a solution that satisfies the minimum norm, such as the least-squares method based on discrete cosine transform, the method based on fast Fourier Least squares method for leaf transformation, etc. Severe undersampling and strong noise are two problems for unwrapping. Qian Xiaofan et al. proposed the transverse shear least squares method (LSBLS), and Guo Yuan et al. proposed the four-way transverse shear least squares method (FSLBS). These algorithms can recover undersampled phase maps, but still cannot effectively solve heavily undersampled wrapped phase maps.

In recent years, adaptive thresholding has been widely used in image segmentation, denoising, dehazing, phase transformation, etc. Foreign scholars Eser Sert and others proposed an adaptive threshold phase conversion three-level calibration algorithm based on the structured light system for three-dimensional object measurement. In terms of image processing, some researchers proposed an edge projection profilometry method based on adaptive threshold removal for background, and some researchers also used adaptive threshold for cell image processing and image denoising. Currently, adaptive thresholding is not widely used for image unwrapping.

Contents of the invention

In view of this, the present invention provides a phase unwrapping method, device, system, computer equipment and storage medium, which has high precision of phase unwrapping, improves the efficiency and accuracy of the real phase restoration of the wrapped phase interferogram, and solves the problem of The problems existing in the existing phase unwrapping algorithm are solved.

The first object of the present invention is to provide a phase unwrapping method.

The second object of the present invention is to provide a phase unwrapping device.

The third object of the present invention is to provide a phase unwrapping system.

A fourth object of the present invention is to provide a computer device.

A fifth object of the present invention is to provide a storage medium.

First purpose of the present invention can be achieved by taking the following technical solutions:

A phase unwrapping method, the method comprising:

Obtain the package phase interferogram;

determine the threshold;

Determine the concave boundary wrapping the phase matrix through the threshold to form a flipping critical line;

automatically flipping and replacing the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix;

Filtering and smoothing the first unwrapped phase matrix to obtain a second unwrapped phase matrix;

calculating and saving the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix;

When the threshold does not reach the preset value, return to re-determine the threshold and perform subsequent operations;

When the threshold reaches a preset value, output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix;

Output the reconstructed real phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

Further, the threshold is a value between 0.9 and 1, wherein 0.9 is the first threshold and 1 is the last threshold; the re-determining the threshold means adding 0.01 to the current threshold; the preset value is 1 .

Further, the determination of the concave boundary wrapping the phase matrix through the threshold to form the flipping critical line specifically includes:

The threshold W is used as the basis for obtaining the concave boundary of the wrapping phase matrix, and the pixels whose phase value is greater than W*phi(max) in the wrapping phase matrix are extracted, and the pixel area is set to 1, where phi(max) is the input phase matrix The maximum value of the phase, that is, the pixel area set to 1 is the concave part, and the rest of the pixels are set to 0.

Further, the automatic flip replacement is performed on the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix, which specifically includes:

Flip the concave part of the wrapped phase matrix, and replace the concave position of the wrapped phase matrix with the flipped concave matrix to obtain a new phase matrix;

When the notch matrix is a non-zero matrix, the notch matrix is flipped, and the notch matrix obtained after the flip is replaced by the position of the notch in the current phase matrix to obtain a new phase matrix;

When the concave matrix is a zero matrix, the current phase matrix is used as the first unwrapped phase matrix and output.

Further, after the acquisition of the wrapped phase interferogram, it also includes:

The wrapping phase interferogram is preprocessed, and the arccosine wrapping phase interferogram can be converted into an arctangent wrapping phase interferogram when necessary in the actual process.

The second purpose of the present invention can be achieved by taking the following technical solutions:

A phase unwrapping device, said device comprising:

The acquisition module is used to acquire the package phase interferogram;

a first determining module, configured to determine a threshold;

The second determination module is used to determine the concave boundary wrapping the phase matrix through a threshold to form a flipping critical line;

Flip replacement module, for automatically flipping and replacing the concave part of the wrapped phase matrix, to obtain the first unwrapped phase matrix;

A processing module, configured to filter and smooth the first unwrapped phase matrix to obtain a second unwrapped phase matrix;

A calculation module, used to calculate and save the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix;

A return module, used to return to re-determine the threshold and perform subsequent operations when the threshold does not reach the preset value;

The first output module is configured to output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix when the threshold reaches a preset value;

The second output module is configured to output the reconstructed true phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

Further, the flip replacement module specifically includes:

The first flip replacement unit is used to flip the concave part of the wrapped phase matrix, and replace the flipped concave matrix with the position of the concave in the wrapped phase matrix to obtain a new phase matrix;

The second flip replacement unit is used to flip the concave matrix when the concave matrix is a non-zero matrix, and replace the concave matrix obtained after the flip with the position of the concave in the current phase matrix to obtain a new phase matrix;

The output unit is configured to use the current phase matrix as the first unwrapped phase matrix and output when the notch matrix is a zero matrix.

Further, after the acquisition module, it also includes:

The preprocessing module is used to preprocess the wrapped phase interferogram, and convert the arccosine wrapped phase interferogram into an arctangent wrapped phase interferogram when necessary in the actual process.

The third purpose of the present invention can be achieved by taking the following technical solutions:

A phase unwrapping system, the system includes sequentially connected semiconductor lasers, adjustable attenuators, beam expanders, pinhole filters, first collimator lens, second collimator lens, phase plate, third collimator lens, video camera and computer, a target object is placed between the first collimator lens and the second collimator lens, the target object is located at the front focal plane of the second collimator lens, and the phase plate is located at the second collimator lens At the back focal plane of the lens, the camera is located at the back focal plane of the third collimating lens;

The laser beam emitted by the semiconductor laser passes through the attenuator, the beam expander, the pinhole filter, and the first collimator lens in order to form a plane light wave to irradiate the target object; the object is obtained on the back focal plane of the second collimator lens The spectrum of the light wave, the phase plate makes the phase modulation area aligned with the zero frequency area of the object light wave spectrum, the light wave passing through the zero frequency area and the light wave passing outside the zero frequency area have undergone different phase modulations, at the back focus of the third collimating lens The package phase interferogram is generated on the surface, and the camera collects the package phase interferogram and inputs it into the computer;

The computer is configured to execute the above phase unwrapping method.

The fourth purpose of the present invention can be achieved by taking the following technical solutions:

A computer device includes a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the above phase unwrapping method is realized.

The fifth purpose of the present invention can be achieved by taking the following technical solutions:

A storage medium stores a program, and when the program is executed by a processor, the above phase unwrapping method is realized.

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

1. After obtaining the wrapped phase interferogram, the present invention determines the threshold, determines the concave boundary of the wrapped phase matrix through the threshold, forms a flip critical line, automatically flips and replaces the concave part of the wrapped phase matrix, and automatically flips and replaces the phase matrix Perform filtering and smoothing processing, calculate and save the relative error of the two phase matrices before and after the filtering and smoothing processing, re-determine the threshold, perform subsequent operations for determining the threshold, and terminate the loop until the threshold reaches the preset value. At this time, determine by comparing each time The relative error saved by the threshold, the minimum relative error is obtained, and the threshold corresponding to the minimum relative error and the phase matrix after filtering and smoothing are output. In the phase unwrapping, the method of phase inversion and recovery phase is adopted. The biggest advantage is to use the threshold to determine the critical line of inversion , can solve the complete real phase with the smallest relative error, thereby improving the accuracy of phase unwrapping, and by automatically finding the threshold, it can effectively avoid setting the threshold manually, provide the correct threshold selection, and improve the efficiency of phase restoration and accuracy.

2. The present invention uses an automatic flip algorithm to process the concave part of the wrapped phase matrix, flips the concave part of the wrapped phase matrix, and replaces the position of the concave part in the wrapped phase matrix with the flipped concave matrix to obtain a new phase At this time, the concave matrix will be judged. If the concave matrix is a non-zero matrix, the concave matrix will be flipped, and the flipped concave matrix will replace the position of the concave in the current phase matrix to obtain a new phase matrix. Until The loop is terminated only when the sag matrix is a zero matrix, and no sag can be found in the unwrapped phase matrix by means of automatic flip replacement.

3. The present invention can accurately restore the real phase in the case of strong noise, has certain anti-noise performance, and solves the problem that noise will affect the accuracy of unwrapping.

4. The error between the reconstructed phase obtained by the present invention and the real phase is small, and the phase unwrapping can be realized for the wrapped phase interferogram with a larger grid size (such as 1501×1501), which improves the accuracy of the phase unwrapped, and is high Accurate, computationally intensive unwrapping provides a new reference method.

5. The present invention is suitable for unwrapping various wrapping phase interferograms with wrapping periods of π, 2π, 3π, etc., and has a wide range of applications and fields.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative effort.

FIG. 1 is an optical path diagram of a phase unwrapping system according to Embodiment 1 of the present invention.

FIG. 2 is a background light intensity diagram of Example 1 of the present invention.

Fig. 3 is a wrapping phase interferogram of Embodiment 1 of the present invention.

FIG. 4 is a flow chart of a phase unwrapping method according to Embodiment 1 of the present invention.

FIG. 5 is a complete flowchart of the phase unwrapping method according to Embodiment 1 of the present invention.

FIG. 6 is a flowchart of an automatic flip replacement algorithm according to Embodiment 1 of the present invention.

FIG. 7 is a real phase distribution diagram obtained by unwrapping using an adaptive threshold flipping algorithm according to Embodiment 1 of the present invention.

Fig. 8 is a real phase distribution diagram obtained by unwrapping using the existing transverse shearing least squares method solution.

Fig. 9 is a structural block diagram of a phase unwrapping device according to Embodiment 3 of the present invention.

Fig. 10 is a structural block diagram of a flip replacement module according to Embodiment 3 of the present invention.

Fig. 11 is a structural block diagram of a computer device according to Embodiment 4 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work belong to the protection of the present invention. scope.

Example 1:

Phase contrast method is a common quantitative phase distribution imaging method, which is widely used in transparent biomedical cell microscopic imaging, transparent material or microlens detection, interferometry, flow field density distribution measurement and other fields. The phase unwrapping process is often involved in the reconstruction of real phase distribution by phase contrast method in the whole field.

Suppose the sample of the target object is a pure phase transparent object, referred to as a phase object, and the parallel light with amplitude A is incident on the object plane, then the complex amplitude of the object light field can be expressed as:

If the influence of the finite aperture of the coherent optical system is ignored, its spectrum is:

If a Zernike phase plate is added to the spectrum surface, its spatial filtering function is:

Among them, t and are the amplitude transmittance and phase shift of the phase plate, respectively. After adding the phase plate, the mathematical expression of the light intensity distribution on the image plane can be written as:

To solve for the phase distribution It is also necessary to know the size of the background light intensity I ₀ of the image plane when the sample and the phase plate are not placed. Considering that when imaging the actual sample, moving the phase plate multiple times will add a lot of unnecessary workload, so without moving the phase plate, directly remove the sample or let the light field pass through the area of the sample that does not contain object information. At this time, the background light intensity of the image plane can be expressed as:

I ₀ =A ² t ² ;

From I(x, y) and I ₀ , the phase principal value distribution of the tested sample can be calculated as:

in, According to the above formula, the phase value in the range of 0 to π can be uniquely determined. Therefore, when the phase change of the measured object is small, that is, when the change range of its phase distribution is within π, The value of can directly reflect the real phase distribution of the object; if the phase of the object exceeds no, by taking two phase-contrast images, that is, the background light intensity map I ₀ and the wrapped phase interferogram I(x, y), since the phase is wrapped, If it cannot be solved directly, it is necessary to use the above arccosine relationship to reconstruct the real phase distribution of the measured phase object through unwrapping.

Fig. 1 is the optical path diagram of the phase unwrapping system of the present embodiment, and this system comprises semiconductor laser 101, adjustable attenuator 102, beam expander mirror 103, pinhole filter 104, the first collimating lens 105, the first connected successively. Two collimating lens 106, phase plate 107, the 3rd collimating lens 108, video camera 109 and computer 110 can carry out experiment to phase contrast method, video camera 109 can adopt CCD video camera, can obtain the parcel phase interference of sample 111 by this video camera 109 As shown in the figure, if the phase distribution of sample 111 exceeds π, unwrapping algorithm processing is required to obtain the real phase distribution or imaging of the sample. The sample 111 selected in the experiment is a microlens array group, and the actual standard maximum thickness of a single microlens spherical surface It is about 3.52 μm, and when the laser beam with a wavelength of 635nm irradiates the microlens array, the maximum phase difference from the top to the bottom of the spherical surface is about 15.88rad (5.055π); displacement A self-made phase plate with a value of 1.1π is used for experiments, and the phase plate 107 is strictly placed on the spectral plane (focal plane) of the imaging lens by fine-tuning the bracket.

The experiment of using the phase unwrapping system to obtain the background light intensity map and the wrapped phase interferogram includes the following steps:

1) After the laser beam emitted from the semiconductor laser 101 passes through the adjustable attenuator 102, the beam expander 103, the pinhole filter 104 and the first collimating lens 105 in sequence, a plane light wave is formed to irradiate the sample 111; wherein, the semiconductor The wavelength of the laser beam emitted by the laser 101 is 635nm, and the focal length of the first collimating lens 105 is 150mm.

2) adjust the position of the second collimating lens 106 so that the sample 111 is positioned at the front focal plane of the second collimating lens 106, and obtain the spectrum of the object light wave on the back focal plane of the second collimating lens 106; wherein, the second The focal length of the collimator lens 106 is 180mm.

3) The phase plate 107 is located at the back focal plane of the second collimator lens 106, adjust the position of the phase plate 107, so that the phase modulation area of the phase plate 107 is aligned with the zero frequency area of the object light wave spectrum, and passes through the zero frequency area (zero frequency component) and the light wave (high-frequency component) passing through the zero-frequency region has undergone different phase modulations, and a wrapping phase interference pattern is generated on the back focal plane of the third collimating lens 108; wherein, the third collimating lens 108 The focal length is 180mm.

3) The camera 109 is located at the back focal plane of the third collimating lens, and the background light intensity map and the package phase interference map are collected by the camera 109, and the collected image can be input into the computer 110 through a data line, or can be transmitted wirelessly The acquired image is input into the computer 110 in a manner, FIG. 2 is a noise-containing background light intensity map, and FIG. 3 is a noise-containing wrapped phase interferogram.

As shown in Fig. 4 and Fig. 5, the present embodiment also provides a kind of phase unwrapping method, and this method adopts the self-adaptive threshold flipping algorithm (SATR) to unwrap, and it is applied in the computer 110, comprises the following steps:

S501. Obtain a package phase interferogram.

The camera 109 collects the background light intensity map and the wrapped phase interferogram, and inputs them into the computer 110. The computer 110 obtains the wrapped phase interferogram, and unwraps the wrapped phase interferogram through subsequent steps.

S502. Perform preprocessing on the wrapped phase interferogram.

The wrapping phase interferogram is preprocessed, and the arccosine wrapping phase interferogram can be converted into an arctangent wrapping phase interferogram when necessary in the actual process.

S503. Determine a threshold.

Specifically, the threshold is recorded as W, 0.9≤W≤1, and the threshold determined for the first time in this embodiment is 0.9.

S504. Determine a concave boundary wrapping the phase matrix by using a threshold to form a flipping critical line.

Specifically, the threshold W is used as the basis for obtaining the concave boundary of the wrapped phase matrix, and the pixels with a phase value greater than W*phi(max) in the wrapped phase matrix are extracted, and the pixel area is set to 1, where phi(max) is the input The maximum value of the phase of the phase matrix, that is, the pixel area set to 1 is the concave part, while the rest of the pixels are set to 0, forming a "wall" with only the concave boundary value of 1, which is the flip critical line for subsequent automatic flip The boundary line of , and record the wrapped phase matrix as phi00, the implementation code is as follows:

S505. Automatically flip and replace the concave part of the wrapped phase matrix to obtain a first unwrapped phase matrix.

The realization of this step S505 adopts the automatic flip replacement algorithm, as shown in Figure 6, specifically includes:

S5051. Flip the concave part of the wrapped phase matrix, and replace the position of the concave part in the wrapped phase matrix with the flipped concave matrix to obtain a new phase matrix.

S5052, judge the concave matrix.

If the concave matrix is a non-zero matrix, go to step S5053, and if the concave matrix is a zero matrix, go to step S5054.

S5053. Flip the concave matrix, and replace the concave position in the current phase matrix with the flipped concave matrix to obtain a new phase matrix;

After the execution of this step is completed, return to step S5052, until it is judged in step S5052 that the concave matrix is a zero matrix, then the loop is terminated and the process enters step S5054.

S5054. Use the current phase matrix as the first unwrapped phase matrix, and output it.

The phase matrix in the step S505 is all recorded as phi00, the symmetric axis of the flip is π for the first time, 2π for the second time, 4π for the third time, and so on; the code to realize the first flip is as follows:

S506. Perform filtering and smoothing processing on the first unwrapped phase matrix to obtain a second unwrapped phase matrix, denoted as phi00T.

S507. Calculate and save the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix.

S508, judging the threshold.

If the threshold W does not reach the preset value, that is, the threshold W is smaller than the preset value, then return to step S503 to re-determine the threshold W; if the threshold W reaches the preset value, that is, equal to the preset value, then go to step S509.

The default value of this embodiment is 1, and re-determining the threshold W refers to adding 0.01 to the current threshold W, that is, the threshold W determined for the second time is 0.91, the threshold W determined for the third time is 0.92, and the threshold W determined for the fourth time is 0.91. The threshold W is 0.93...and so on, until the judgment threshold W is 1, the loop is terminated, that is, the last determined threshold W is 1, and a total of 11 thresholds W have to be calculated, that is, 11 automatic flip replacements have been performed.

S509. Output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix.

The minimum relative error is obtained by comparing the relative error stored in the threshold W each time, and the threshold W corresponding to the minimum relative error and the second unwrapped phase matrix phi00T are output, and the threshold W is the optimal threshold.

The above steps S502-S509 are implemented by using the findSunken function, which is the core function of the adaptive threshold flipping algorithm. When setting the threshold in the function, a variable W is defined. This value is the key to realize the subsequent automatic flipping replacement operation. Each threshold W corresponds to An automatic flip replacement, save the relative error between the first unwrapped phase matrix phi00 after each automatic flip replacement and the second unwrapped phase matrix phi00T after filtering and smoothing, and find the threshold W corresponding to the minimum relative error and the second solution Wrap the phase matrix phi00T and output it, so that the threshold W is constantly updated to ensure the accuracy of the operation.

S510. Output a reconstructed true phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

The real phase distribution obtained by unwrapping using the Adaptive Threshold Reversal Algorithm (SATR) of this embodiment, as shown in FIG. The distribution diagram is shown in Figure 8. The phase maximum value of a single microlens obtained by SATR inversion is about 16.35rad, and the thickness is about 3.62μm. Compared with the parameters of the microlens array, there is an absolute error of about 0.10μm. The relative error is 2.84%; the phase maximum value of a single microlens obtained by LSBLS inversion is about 15.22rad, and the thickness is about 3.37μm. Compared with the parameters of the microlens array, there is an absolute error of about 0.15μm, and a relative error of 4.16 %. It shows that the error between the reconstructed phase obtained by inversion and the real phase by the method of this embodiment is small, and the precision is high.

Those skilled in the art can understand that all or part of the steps in the method for implementing the above embodiments can be completed by instructing related hardware through a program, and the corresponding program can be stored in a computer-readable storage medium.

It should be noted that although method operations of the above-described embodiments are described in a particular order in the drawings, this does not require or imply that the operations must be performed in that particular order, or that all illustrated operations must be performed to achieve the desired results. . Rather, the depicted steps may be performed in an altered order. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and/or one step may be decomposed into multiple steps for execution.

Example 3:

As shown in FIG. 9, this embodiment provides a phase unwrapping device, which can be applied to a computer, and includes an acquisition module 901, a preprocessing module 902, a first determination module 903, a second determination module 904, an inversion Replacement module 905, processing module 906, calculation module 907, return module 908, first output module 909 and second output module 910, the specific functions of each module are as follows:

The acquiring module 901 is configured to acquire the wrapping phase interferogram.

The preprocessing module 902 is used to preprocess the wrapping phase interferogram, and convert the arccosine wrapping phase interferogram into an arctangent wrapping phase interferogram if necessary in the actual process.

The first determining module 903 is configured to determine a threshold.

The second determining module 904 is configured to determine a concave boundary wrapping the phase matrix through a threshold to form a flipping critical line.

The flip replacement module 905 is configured to automatically flip and replace the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix.

The processing module 906 is configured to perform filtering and smoothing processing on the first unwrapped phase matrix to obtain a second unwrapped phase matrix.

The calculation module 907 is configured to calculate and save the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix.

The return module 908 is configured to return to re-determine the threshold and perform subsequent operations when the threshold does not reach the preset value.

The first output module 909 is configured to output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix when the threshold reaches a preset value.

The second output module 910 is configured to output the reconstructed true phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

Further, the flip replacement module 905 is shown in Figure 10, specifically including:

The first inverting and replacing unit 9051 is configured to invert the concave part of the wrapped phase matrix, and replace the position of the depressed part in the wrapped phase matrix with the inverted concave matrix to obtain a new phase matrix.

The second inverting and replacing unit 9052 is configured to invert the notched matrix when the notched matrix is a non-zero matrix, and replace the position of the notched place in the current phase matrix with the inverted notched matrix to obtain a new phase matrix.

The output unit 9053 is configured to use the current phase matrix as the first unwrapped phase matrix and output it when the notch matrix is a zero matrix.

For the specific implementation of each module in this embodiment, please refer to the phase unwrapping method in the above-mentioned embodiment 1, which will not be repeated here; it should be noted that the device provided in this embodiment only uses the division of the above-mentioned functional modules as an example It should be noted that in practical applications, the above-mentioned function allocation can be completed by different functional modules according to needs, that is, the internal structure is divided into different functional modules, so as to complete all or part of the above-described functions.

It can be understood that the terms "first" and "second" used in the device of this embodiment can be used to describe various units, but these units are not limited by these terms. These terms are only used to distinguish the first module from another module. For example, without departing from the scope of the present invention, a first output module may be referred to as a second output module, and similarly, a second output module may be referred to as a first output module, the first output module and The second output modules are both output modules, but they are not the same output module.

Example 4:

This embodiment provides a computer device, which may be a computer, as shown in FIG. The device is used to provide computing and control capabilities, the memory includes a non-volatile storage medium 1106 and an internal memory 1107, the non-volatile storage medium 906 stores an operating system, computer programs and databases, and the internal memory 1107 is non-volatile The operating system in the storage medium and the computer program provide an environment for running. When the processor 1102 executes the computer program stored in the memory, the phase unwrapping method of the above-mentioned embodiment 1 is implemented, as follows:

Obtain the package phase interferogram;

determine the threshold;

Determine the concave boundary wrapping the phase matrix through the threshold to form a flipping critical line;

automatically flipping and replacing the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix;

Filtering and smoothing the first unwrapped phase matrix to obtain a second unwrapped phase matrix;

calculating and saving the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix;

When the threshold does not reach the preset value, return to re-determine the threshold and perform subsequent operations;

When the threshold reaches a preset value, output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix;

Output the reconstructed real phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

Further, after the acquisition of the wrapping phase interferogram, it also includes: preprocessing the wrapping phase interferogram, and converting the arccosine wrapping phase interferogram into an arctangent wrapping phase interferogram when necessary in the actual process.

Example 5:

This embodiment provides a storage medium, which is a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, when the processor executes the computer program stored in the memory, the first embodiment above is realized. The phase unwrapping method of is as follows:

Obtain the package phase interferogram;

determine the threshold;

Determine the concave boundary wrapping the phase matrix through the threshold to form a flipping critical line;

automatically flipping and replacing the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix;

Filtering and smoothing the first unwrapped phase matrix to obtain a second unwrapped phase matrix;

calculating and saving the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix;

When the threshold does not reach the preset value, return to re-determine the threshold and perform subsequent operations;

When the threshold reaches a preset value, output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix;

Output the reconstructed real phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error.

Further, after the acquisition of the wrapping phase interferogram, it also includes: preprocessing the wrapping phase interferogram, and converting the arccosine wrapping phase interferogram into an arctangent wrapping phase interferogram when necessary in the actual process.

The storage medium described in this embodiment may be a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a U disk, a mobile hard disk, and the like.

In summary, the present invention determines the threshold value after obtaining the wrapped phase interferogram, and determines the concave boundary of the wrapped phase matrix through the threshold to form a flipping critical line, automatically flips and replaces the concave part of the wrapped phase matrix, and automatically flips and replaces The phase matrix of the phase matrix is filtered and smoothed, and the relative error of the two phase matrices before and after the smoothing is calculated and saved. The threshold is re-determined, and the follow-up operation of determining the threshold is performed. The loop is not terminated until the threshold reaches the preset value. At this time, by comparing Each time the relative error saved by the threshold is determined, the minimum relative error is obtained, and the threshold corresponding to the minimum relative error and the phase matrix after filtering and smoothing are output. In the phase unwrapping, the method of phase inversion and recovery phase is adopted. The biggest advantage is to use the threshold to determine Flipping the critical line can solve the complete real phase with the smallest relative error, thereby improving the accuracy of phase unwrapping, and by automatically finding the threshold, it can effectively avoid setting the threshold manually, provide the correct threshold selection, and improve the phase restoration. efficiency and accuracy.

The above is only a preferred embodiment of the patent of the present invention, but the scope of protection of the patent of the present invention is not limited thereto. Equivalent replacements or changes to the technical solutions and their inventive concepts all fall within the scope of protection of the invention patent.

Claims (10)

1. A phase unwrapping method, characterized in that the method comprises: Obtain the package phase interferogram; determine the threshold; Determine the concave boundary wrapping the phase matrix through the threshold to form a flipping critical line; automatically flipping and replacing the concave part of the wrapped phase matrix to obtain the first unwrapped phase matrix; Filtering and smoothing the first unwrapped phase matrix to obtain a second unwrapped phase matrix; calculating and saving the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix; When the threshold does not reach the preset value, return to re-determine the threshold and perform subsequent operations; When the threshold reaches a preset value, output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix; Output the reconstructed real phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error. 2. The phase unwrapping method according to claim 1, wherein the threshold is a value between 0.9 and 1, wherein 0.9 is the first threshold, and 1 is the last threshold; the re-determined threshold is Refers to adding 0.01 to the current threshold; the preset value is 1. 3. The phase unwrapping method according to any one of claims 1-2, wherein the determination of the concave boundary wrapping the phase matrix through a threshold to form a flipping critical line specifically includes: The threshold W is used as the basis for obtaining the concave boundary of the wrapping phase matrix, and the pixels whose phase value is greater than W*phi(max) in the wrapping phase matrix are extracted, and the pixel area is set to 1, where phi(max) is the input phase matrix The maximum value of the phase, that is, the pixel area set to 1 is the concave part, and the rest of the pixels are set to 0. 4. The phase unwrapping method according to any one of claims 1-2, characterized in that, automatically flipping and replacing the concave part of the wrapping phase matrix to obtain the first unwrapping phase matrix, specifically comprising: Flip the concave part of the wrapped phase matrix, and replace the concave position of the wrapped phase matrix with the flipped concave matrix to obtain a new phase matrix; When the notch matrix is a non-zero matrix, the notch matrix is flipped, and the notch matrix obtained after the flip is replaced by the position of the notch in the current phase matrix to obtain a new phase matrix; When the concave matrix is a zero matrix, the current phase matrix is used as the first unwrapped phase matrix and output. 5. The phase unwrapping method according to any one of claims 1-2, wherein after said obtaining the wrapped phase interferogram, further comprising: Preprocess the wrapped phase interferogram. 6. A phase unwrapping device, characterized in that the device comprises: The acquisition module is used to acquire the package phase interferogram; a first determining module, configured to determine a threshold; The second determination module is used to determine the concave boundary wrapping the phase matrix through a threshold to form a flipping critical line; Flip replacement module, for automatically flipping and replacing the concave part of the wrapped phase matrix, to obtain the first unwrapped phase matrix; A processing module, configured to filter and smooth the first unwrapped phase matrix to obtain a second unwrapped phase matrix; A calculation module, used to calculate and save the relative error between the first unwrapped phase matrix and the second unwrapped phase matrix; A return module, used to return to re-determine the threshold and perform subsequent operations when the threshold does not reach the preset value; The first output module is configured to output the threshold corresponding to the minimum relative error and the second unwrapped phase matrix when the threshold reaches a preset value; The second output module is configured to output the reconstructed true phase distribution according to the second unwrapped phase matrix corresponding to the minimum relative error. 7. The phase unwrapping device according to claim 6, wherein the flip replacement module specifically comprises: The first flip replacement unit is used to flip the concave part of the wrapped phase matrix, and replace the flipped concave matrix with the position of the concave in the wrapped phase matrix to obtain a new phase matrix; The second flip replacement unit is used to flip the concave matrix when the concave matrix is a non-zero matrix, and replace the concave matrix obtained after the flip with the position of the concave in the current phase matrix to obtain a new phase matrix; The output unit is configured to use the current phase matrix as the first unwrapped phase matrix and output when the notch matrix is a zero matrix. 8. A phase unwrapping system, characterized in that the system comprises semiconductor lasers, adjustable attenuators, beam expanders, pinhole filters, the first collimating lens, the second collimating lens, phase plate, the third collimating lens, video camera and computer, the target object is placed between the first collimating lens and the second collimating lens, the target object is located at the front focal plane of the second collimating lens, the phase the plate is located at the back focal plane of the second collimating lens, and the camera is located at the back focal plane of the third collimating lens; The laser beam emitted by the semiconductor laser passes through the attenuator, the beam expander, the pinhole filter, and the first collimator lens in order to form a plane light wave to irradiate the target object; the object is obtained on the back focal plane of the second collimator lens The spectrum of the light wave, the phase plate makes the phase modulation area aligned with the zero frequency area of the object light wave spectrum, the light wave passing through the zero frequency area and the light wave passing outside the zero frequency area have undergone different phase modulations, at the back focus of the third collimating lens The package phase interferogram is generated on the surface, and the camera collects the package phase interferogram and inputs it into the computer; The computer is configured to execute the phase unwrapping method described in any one of claims 1-5. 9. A computer device, comprising a processor and a memory for storing a program executable by the processor, wherein when the processor executes the program stored in the memory, the phase described in any one of claims 1-5 is realized Unwrap method. 10. A storage medium storing a program, wherein when the program is executed by a processor, the phase unwrapping method according to any one of claims 1-5 is implemented.