WO2023142628A1 - Adaptive speckle interferometry method and system - Google Patents

Adaptive speckle interferometry method and system Download PDF

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WO2023142628A1
WO2023142628A1 PCT/CN2022/133154 CN2022133154W WO2023142628A1 WO 2023142628 A1 WO2023142628 A1 WO 2023142628A1 CN 2022133154 W CN2022133154 W CN 2022133154W WO 2023142628 A1 WO2023142628 A1 WO 2023142628A1
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speckle
fusion
images
deformation
phase shift
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PCT/CN2022/133154
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French (fr)
Chinese (zh)
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张东升
张涛
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上海大学绍兴研究院
上海大学
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge

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  • the invention relates to the technical field of optical measurement, in particular to an adaptive speckle interferometry method and system.
  • Speckle interferometry is a precision measurement technique based on the principle of optical interference. Depending on the specific optical arrangement, speckle interferometry can be used to measure full-field deformation both in-plane and out-of-plane. Shear imaging simplifies the optical setup by using a shear device to measure the derivative of the out-of-plane deformation by setting the shear amount and shear direction. Interferometers use the wave properties of coherent light to analyze surface properties, including in-plane and out-of-plane displacements and gradients. If a controllable phase shift is introduced in the interferometer, the optical path difference between the two beams produces a given constant phase. By introducing phase shift technology, the contrast of the interferogram has been greatly improved, and precise measurement becomes possible.
  • Phase shift can be introduced in two ways.
  • the spatial phase shift technique acquires only one fringe image with a spatial carrier. Since Fourier analysis is usually required to extract the frequency spectrum of interest, it is difficult to achieve real-time phase calculation.
  • the time phase shift technology directly acquires multiple interference images with known phase shifts, combined with parallel computing, real-time calculation of the phase difference representing physical information.
  • Speckle interferometry requires one or more beams of coherent light to illuminate the sample surface.
  • the illumination of the sample surface is uniform so that the pixel grayscale in the image is directly proportional to the light intensity. This requirement can usually be met provided that no overexposure or underexposure occurs.
  • Under laser beam illumination for planar samples, it is easy to avoid overexposure by tilting the sample at an angle to the light source to avoid direct reflections.
  • For curved samples however, specialized placement poses are often required to move bright spots out of the image. But for spherical or cylindrical surfaces, no matter how the object or light path is arranged, there will be overexposed areas.
  • Another method is to perform surface treatment before the reflectance reduction of the test sample surface. However, in the non-destructive inspection of rubber-coated structures that do not allow surface treatment, such strong reflection spots can lead to loss of measurement information in the overexposed regions of the speckle image.
  • the quality of the calculated phase image is often poor due to factors such as illumination arrangement, object surface curvature, and sample reflectivity, resulting in low applicability of existing methods and relatively complex arrangement, resulting in low accuracy of phase measurement.
  • the purpose of the present invention is to provide an adaptive speckle interferometry method and system, which improves the stability and applicability of phase measurement.
  • the present invention provides the following scheme:
  • An adaptive speckle interferometry method comprising:
  • each phase shift obtains a group of speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and number of exposures of the speckle images of each group of objects to be detected, and obtains four Groups of speckle images, denoted as four groups of reference speckle images;
  • each phase shift acquires a set of deformed speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and exposure of each group of deformed speckle images of the object to be detected The number of times, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
  • each set of reference speckle fusion images includes four reference speckle fusion images
  • each set of comparison speckle fusion images includes four contrasting speckle fusion images Speckle fusion image
  • Image fusion is performed on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four speckle fusion images before deformation;
  • Image fusion is performed on the contrasting speckle fusion images corresponding to the phases of the set number of comparison speckle fusion images respectively, and four deformed speckle fusion images are obtained;
  • the deformation phase of the object to be detected is determined according to four speckle fusion images before deformation and four speckle fusion images after deformation.
  • determining the deformation phase of the object to be detected according to four speckle fusion images before deformation and four speckle fusion images after deformation specifically includes:
  • R 01 represents the speckle fusion image corresponding to the first phase shift before deformation
  • R 02 represents the speckle fusion image corresponding to the second phase shift before deformation
  • R 03 represents the first phase shift before deformation
  • R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation
  • R 11 represents the speckle fusion image corresponding to the first phase shift after deformation
  • R 12 represents the speckle fusion image after deformation
  • R 13 represents the speckle fusion image corresponding to the third phase shift after deformation
  • R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  • the reference speckle fusion image is expressed as:
  • the contrastive speckle fusion image is expressed as:
  • k represents the exposure sequence number
  • N 1 and N 2 both represent the number of exposures
  • R 0i represents the reference speckle fusion image after the i-th phase shift
  • R 1i represents the comparison speckle fusion image after the i-th phase shift
  • i ⁇ [1,2,3,4] Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation
  • an adaptive speckle interferometry method further includes: using a computer to control piezoelectric ceramics to generate phase changes to implement the four-step phase shift in the four-step phase shift algorithm.
  • the invention also discloses an adaptive speckle interferometry system, including:
  • Four groups of reference speckle image acquisition modules are used to obtain a group of speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate the speckle images of each group of objects to be detected
  • the exposure time and the number of exposures of the speckle images are used to obtain four sets of speckle images, which are recorded as four sets of reference speckle images;
  • the acquisition module of four reference speckle fusion images is used to perform image fusion on each set of reference speckle images respectively to obtain four reference speckle fusion images;
  • comparison speckle image acquisition module used to obtain a set of deformed speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate each group of objects to be detected
  • the exposure time and number of exposures of the deformed speckle image, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
  • the acquisition module of four contrasting speckle fusion images is used to perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images;
  • a reference speckle fusion image with a set number of groups and a comparison speckle fusion image obtaining module configured to obtain a reference speckle fusion image with a set number of groups and a contrastive speckle fusion image with a set number of groups, and each set of reference speckle fusion images
  • the images all include four reference speckle fusion images, and each group of comparison speckle fusion images includes four comparison speckle fusion images;
  • the pre-deformation speckle fusion image determination module is used to perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four pre-deformation speckle fusion images;
  • the post-deformation speckle fusion image determination module is used to perform image fusion on the comparison speckle fusion images corresponding to the phases in the set number of comparison speckle fusion images respectively, to obtain four post-deformation speckle fusion images;
  • the phase determination module is configured to determine the deformation phase of the object to be detected based on parallel computing according to four speckle fusion images before deformation and four speckle fusion images after deformation.
  • phase determination module specifically includes:
  • the phase determination unit is used for GPU-based parallel computing, according to the formula calculating the phase of deformation of the object to be detected;
  • R 01 represents the speckle fusion image corresponding to the first phase shift before deformation
  • R 02 represents the speckle fusion image corresponding to the second phase shift before deformation
  • R 03 represents the first phase shift before deformation
  • R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation
  • R 11 represents the speckle fusion image corresponding to the first phase shift after deformation
  • R 12 represents the speckle fusion image after deformation
  • R 13 represents the speckle fusion image corresponding to the third phase shift after deformation
  • R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  • the reference speckle fusion image is expressed as:
  • the contrastive speckle fusion image is expressed as:
  • k represents the exposure sequence number
  • N 1 and N 2 both represent the number of exposures
  • R 0i represents the reference speckle fusion image after the i-th phase shift
  • R 1i represents the comparison speckle fusion image after the i-th phase shift
  • i ⁇ [1,2,3,4] Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation
  • an adaptive speckle interferometry system further includes: using a computer to control piezoelectric ceramics to generate phase changes to implement the four-step phase shift in the four-step phase shift algorithm.
  • the invention discloses the following technical effects:
  • An adaptive speckle interferometry method and system by fusing pre-deformed reference speckle images and deformed speckle images obtained at different exposure times, improves the performance of speckle images obtained by four-step phase shift algorithm at different phases Quality, through image fusion of speckle images with different exposure levels, adaptive speckle interferometry is performed under the condition of uneven exposure brightness, so as to improve the stability and applicability of phase measurement.
  • Fig. 1 is a schematic flow chart of an adaptive speckle interferometry method according to the present invention
  • Fig. 2 is a schematic diagram of distribution characteristics of multiple exposure image intensity regions within a period of exposure time in the present invention
  • Fig. 3 is the schematic diagram of HDRPR real-time detection method of the present invention.
  • FIG. 4 is a schematic diagram of the test and detection environment for the test piece according to the embodiment of the present invention.
  • Fig. 5 is the schematic diagram of test result of the embodiment of the present invention.
  • Fig. 6 is a schematic structural diagram of an adaptive speckle interferometry system according to the present invention.
  • the purpose of the present invention is to provide an adaptive speckle interferometry method and system, which improves the stability and applicability of phase measurement.
  • Fig. 1 is a schematic flow chart of an adaptive speckle interferometry method according to the present invention. As shown in Fig. 1, an adaptive speckle interferometry method includes:
  • Step 101 Based on the four-step phase shift algorithm, each phase shift acquires a group of speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and number of exposures of the speckle images of each group of objects to be detected , to obtain four sets of speckle images, which are recorded as four sets of reference speckle images.
  • step 101 specifically includes: based on the computer controlling the piezoelectric ceramics to generate a phase change, and adopting a four-step phase shift algorithm to obtain four reference speckle fusion images of the object to be detected.
  • a set of speckle images of the object to be detected includes speckle images with different exposure levels. As the exposure time gradually increases, the speckle image changes from underexposed areas larger than normal exposure areas to underexposed areas decreasing, overexposed areas increasing, until underexposed The area is reduced to 0.
  • the normal exposure area is an image grayscale value between 0 and 255; when the image grayscale value is greater than or equal to 255, it is an overexposed area, and when the image grayscale value is less than or equal to 0, it is an underexposed area.
  • Step 102 performing image fusion on each set of reference speckle images respectively, to obtain four reference speckle fusion images.
  • step 102 specifically includes: performing image fusion on each set of reference speckle images respectively at the CPU end to obtain four reference speckle fusion images.
  • Step 103 Based on the four-step phase shift algorithm, each phase shift acquires a set of deformed speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure of each group of deformed speckle images of the object to be detected Time and number of exposures, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images.
  • a set of deformed speckle images of the object to be detected includes speckle images with different exposure levels. As the exposure time gradually increases, the speckle image changes from underexposed areas larger than normal exposure areas to underexposed areas decreasing and overexposed areas increasing until The underexposed areas are reduced to 0.
  • the number of exposures and a set of exposure times are calibrated from short to long.
  • the exposure is generally adjusted by the exposure time of the digital camera. Because the selection of original images is directly related to fusion quality and computational efficiency, the determination of exposure time is crucial for image fusion. Since the overexposed or underexposed areas are often found to be local spots in the speckle image, the speckle image can be divided into three parts, namely the normal exposure area A, the overexposed area V and the underexposed area U.
  • the camera's exposure time is initially set to zero.
  • the image is overall darker in the underexposed state.
  • bright areas in the field of view become visible and gradually saturate as the exposure time increases.
  • the corresponding exposure time of the first speckle image I (1) is determined.
  • Figure 2(a) only the area A (1) inside the circle is normally exposed in the image, and the rest of the area U (1) is still underexposed (shaded area).
  • Figure 2(b) determines the corresponding exposure time for the second speckle image I (2) .
  • the image is divided into three regions, including the overexposed region V (1) , the normal exposed region A (2) and the underexposed region U (2) .
  • the exposure time is continuously adjusted until the underexposed areas are reduced. Following such a procedure, a series of exposure times is determined. Once a series of exposure times is determined, a series of speckle images of the same phase shift step can be obtained before and after deformation.
  • the speckle image fusion of the present invention is an efficient and stable image fusion algorithm that can be used for time phase shift.
  • the present invention adopts a real-time detection strategy: use the computer to control the piezoelectric ceramics to control the moving step of the driving mirror, under each phase shift, expose multiple times according to the standard, and use the proposed fusion algorithm to fuse multiple Exposure of the speckle image.
  • image fusion is done on the CPU side, and the fused speckle image is sent to the GPU side for filtering and phase calculation.
  • the present invention adopts four-step phase shift, and the phase shift range is cycled from small to large, and a phase image is output for each phase shift.
  • Step 104 Perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images.
  • step 104 specifically includes: performing image fusion on each group of contrasting speckle images respectively at the CPU end to obtain four contrasting speckle fusion images.
  • Step 105 Obtain reference speckle fusion images with a set number of groups and comparison speckle fusion images with a set number of groups, each set of reference speckle fusion images includes four reference speckle fusion images, and each set of comparison speckle fusion images Four contrasting speckle fusion images are included.
  • Step 106 Perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images respectively, to obtain four speckle fusion images before deformation.
  • Step 107 Perform image fusion on the contrasting speckle fusion images of the corresponding phases in the set number of contrasting speckle fusion images, respectively, to obtain four deformed speckle fusion images.
  • Step 108 Based on parallel calculation, determine the deformation phase of the object to be detected according to the four speckle fusion images before deformation and the four speckle fusion images after deformation.
  • step 108 specifically includes: based on GPU parallel computing, determining the deformation phase of the object to be detected according to four speckle fusion images before deformation and four speckle fusion images after deformation; four speckle fusion images after deformation and four speckle fusion images before deformation All speckle fusion images are stored in GPU memory.
  • R 01 represents the speckle fusion image corresponding to the first phase shift before deformation
  • R 02 represents the speckle fusion image corresponding to the second phase shift before deformation
  • R 03 represents the first phase shift before deformation
  • R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation
  • R 11 represents the speckle fusion image corresponding to the first phase shift after deformation
  • R 12 represents the speckle fusion image after deformation
  • R 13 represents the speckle fusion image corresponding to the third phase shift after deformation
  • R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  • the reference speckle fusion image is expressed as:
  • the contrastive speckle fusion image is expressed as:
  • k represents the exposure sequence number
  • N 1 and N 2 both represent the number of exposures
  • R 0i represents the reference speckle fusion image after the i-th phase shift
  • R 1i represents the comparison speckle fusion image after the i-th phase shift
  • i ⁇ [1,2,3,4] Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation
  • the process of calculating the phase by four-step phase shift needs to record four images before deformation and four images after deformation:
  • a is the background intensity of the speckle image
  • b is the modulation item of the speckle image
  • i is the ordinal number of the phase shift step.
  • I 0i and I 1i denote the speckle image before and after deformation, respectively.
  • the present invention records multiple speckle images with a given exposure level under each phase shift step, and the speckle image intensity at this time can be described as:
  • the speckle images with different exposures have a monotonic relationship.
  • HDRPR High Dynamic Range Phase Reconstruction
  • HDRPR is a non-contact optical method that can be applied to submicron deformation detection on shiny surfaces. This technique is more time-consuming than traditional methods.
  • the present invention proposes a stable and effective implementation strategy. This strategy is a technical solution that combines multi-exposure image acquisition with cameras, piezoelectric ceramic control and CPU-GPU programming.
  • the piezoceramic is controlled to produce a phase change of ⁇ /2 by inputting a specific DC voltage, and the phase cycles from small to large in the range of 0 to 3 ⁇ /2.
  • the formula (2) in step 2 is fused to obtain a speckle image.
  • the speckle image is stored in the memory of the host. At this time, copy the fused speckle image to the memory of the client. This process is repeated continuously during the measurement.
  • the GPU application formula (4) is called to calculate the phase CUDA is an efficient computing platform that can be used to call GPU.
  • the thread blocks are arranged in a one-dimensional form and the GPU thread warp equal to the image resolution is predefined to ensure high concurrency of dephasing and filtering.
  • the calculated phase image is copied back to the host and displayed in real-time in a threaded manner. It should be noted that in a measurement, the memory block storing R 0i is only updated once, and the memory block storing R 1i is updated cyclically.
  • Figure 3 presents a schematic diagram of this strategy.
  • An adaptive speckle interferometry method of the present invention is applied to detect the debonding defect detection of the inner wall of the rubber-metal bonded cylindrical shell, and the measurement process is as follows:
  • test results are shown in Figure 5.
  • the upper images of (a), (b) and (c) in Figure 5 are speckle images, and the lower images are the corresponding phase images.
  • the phase image calculated based on HDRPR is well integrated with the phase information encoded by speckle images with different exposures, and can realize real-time detection requirements.
  • Fig. 6 is a schematic structural diagram of an adaptive speckle interferometry system according to the present invention. As shown in Fig. 6, an adaptive speckle interferometry system includes:
  • the four-group reference speckle image acquisition module 201 is configured to acquire a group of speckle images of the object to be detected according to the exposure time from short to long for each phase shift based on the four-step phase shift algorithm, and calibrate each group of the object to be detected
  • the exposure time and number of exposures of the speckle image, four sets of speckle images are obtained, and recorded as four sets of reference speckle images;
  • the four reference speckle fusion image acquisition module 202 is configured to perform image fusion on each set of reference speckle images respectively, and acquire four reference speckle fusion images;
  • the four-group comparison speckle image acquisition module 203 is used to obtain a group of deformed speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate each group of speckle images to be detected
  • the exposure time and number of exposures of the speckle image after the deformation of the object, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
  • the acquisition module 204 of four contrasting speckle fusion images is configured to perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images;
  • a reference speckle fusion image with a set number of groups and a comparison speckle fusion image obtaining module 205 configured to obtain a reference speckle fusion image with a set number of groups and a comparison speckle fusion image with a set number of groups, each group of reference speckle fusion
  • the fused images all include four reference speckle fusion images, and each group of contrasting speckle fusion images includes four contrasting speckle fusion images;
  • the pre-deformation speckle fusion image determination module 206 is configured to perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four pre-deformation speckle fusion images;
  • Deformed speckle fusion image determination module 207 configured to perform image fusion on contrasting speckle fusion images of corresponding phases in the set number of comparison speckle fusion images respectively, to obtain four deformed speckle fusion images;
  • the phase determining module 208 is configured to determine the phase of deformation of the object to be detected based on parallel computing according to four speckle fusion images before deformation and four speckle fusion images after deformation.
  • the phase determination module 208 specifically includes:
  • the phase determination unit is used for GPU-based parallel computing, according to the formula calculating the phase of deformation of the object to be detected;
  • R 01 represents the speckle fusion image corresponding to the first phase shift before deformation
  • R 02 represents the speckle fusion image corresponding to the second phase shift before deformation
  • R 03 represents the first phase shift before deformation
  • R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation
  • R 11 represents the speckle fusion image corresponding to the first phase shift after deformation
  • R 12 represents the speckle fusion image after deformation
  • R 13 represents the speckle fusion image corresponding to the third phase shift after deformation
  • R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  • the reference speckle fusion image is expressed as:
  • the contrastive speckle fusion image is expressed as:
  • k represents the exposure sequence number
  • N 1 and N 2 both represent the number of exposures
  • R 0i represents the reference speckle fusion image after the i-th phase shift
  • R 1i represents the deformed speckle fusion image after the i-th phase shift
  • i ⁇ [1,2,3,4] Indicates the speckle image at the kth exposure after the ith phase shift before deformation
  • An adaptive speckle interferometry system further includes: a phase change driving module, which is used to use a computer to control piezoelectric ceramics to generate phase changes to realize the four-step phase shift in the four-step phase shift algorithm.
  • each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.
  • the description is relatively simple, and for the related information, please refer to the description of the method part.

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Abstract

An adaptive speckle interferometry method, comprising: on the basis of a four-step phase-shifting algorithm, acquiring a group of speckle images of an object to be detected for each phase shift according to exposure time from short to long, and acquiring four groups of reference speckle images (101); performing image fusion on each group of reference speckle images, to acquire four reference speckle fused images (102); on the basis of the four-step phase-shifting algorithm, acquiring four groups of speckle images after deformation (103); performing image fusion on each group of speckle images after deformation, to acquire four speckle fused images after deformation (104); storing the four speckle fused images after deformation and the four reference speckle fused images in a GPU memory, determining a phase of deformation of the object to be detected according to the four speckle fused images after deformation and the four reference speckle fused images by means of parallel calculations (108), and completing real-time display. The stability and applicability of phase measurement are improved. Further provided is an adaptive speckle interferometry system.

Description

一种自适应散斑干涉测量方法及系统An adaptive speckle interferometry method and system 技术领域technical field
本发明涉及光学测量技术领域，特别是涉及一种自适应散斑干涉测量方法及系统。The invention relates to the technical field of optical measurement, in particular to an adaptive speckle interferometry method and system.
背景技术Background technique
散斑干涉计量法是一种基于光学干涉原理的精密测量技术。根据特定的光学布置，散斑干涉测量可用于测量面内和面外的全场变形。剪切成像通过使用剪切装置简化了光学布置，通过设置剪切量和剪切方向测量平面外变形的导数。干涉仪利用相干光的波动特性分析表面特性，包括平面内和平面外的位移以及梯度。如果在干涉仪中引入可控相移，则两光束之间的光程差会产生给定的恒定相位。通过引入相移技术，干涉图的对比度得到了很大的提高，精密测量成为可能。相移可以通过两种方式引入。空间相移技术仅获取一个带有空间载波的条纹图像。由于通常需要傅里叶分析来提取目标频谱，因此很难实现实时相位计算。而时间相移技术直接获取具有已知相移的多个干涉图像，结合并行计算，实时计算代表物理信息的相位差。Speckle interferometry is a precision measurement technique based on the principle of optical interference. Depending on the specific optical arrangement, speckle interferometry can be used to measure full-field deformation both in-plane and out-of-plane. Shear imaging simplifies the optical setup by using a shear device to measure the derivative of the out-of-plane deformation by setting the shear amount and shear direction. Interferometers use the wave properties of coherent light to analyze surface properties, including in-plane and out-of-plane displacements and gradients. If a controllable phase shift is introduced in the interferometer, the optical path difference between the two beams produces a given constant phase. By introducing phase shift technology, the contrast of the interferogram has been greatly improved, and precise measurement becomes possible. Phase shift can be introduced in two ways. The spatial phase shift technique acquires only one fringe image with a spatial carrier. Since Fourier analysis is usually required to extract the frequency spectrum of interest, it is difficult to achieve real-time phase calculation. The time phase shift technology directly acquires multiple interference images with known phase shifts, combined with parallel computing, real-time calculation of the phase difference representing physical information.
散斑干涉测量需要一束或多束相干光来照亮样品表面。为了获得高质量的干涉图，通常样品表面的照明是均匀的，以便图像中的像素灰度与光强度呈正比关系。在没有发生过度曝光或曝光不足的情况下，通常可以满足此要求。在激光束照射下，对于平面样品，很容易通过将样品倾斜到与光源成一定角度以避免直接反射来避免过度曝光。而对于曲面样本，通常需要专门的放置姿态才能将亮点移出图像。但是对于球面或圆柱面，无论物体或光路如何布置，都会出现过度曝光区域。另一种方法是在测试样品表面的反射率降低之前进行表面处理。然而，在不允许表面处理的橡胶涂层结构的无损检测中，这类强反射光斑会导致散斑图像的过度曝光区域丢失测量信息。Speckle interferometry requires one or more beams of coherent light to illuminate the sample surface. In order to obtain high-quality interferograms, usually the illumination of the sample surface is uniform so that the pixel grayscale in the image is directly proportional to the light intensity. This requirement can usually be met provided that no overexposure or underexposure occurs. Under laser beam illumination, for planar samples, it is easy to avoid overexposure by tilting the sample at an angle to the light source to avoid direct reflections. For curved samples, however, specialized placement poses are often required to move bright spots out of the image. But for spherical or cylindrical surfaces, no matter how the object or light path is arranged, there will be overexposed areas. Another method is to perform surface treatment before the reflectance reduction of the test sample surface. However, in the non-destructive inspection of rubber-coated structures that do not allow surface treatment, such strong reflection spots can lead to loss of measurement information in the overexposed regions of the speckle image.
综上所述，因光照布置、物体表面曲率和样品反射率的因素常导致计算出的相位图像质量差，导致现有的方法适用性不高，布置相对复杂，从而造成相位测量准确性低。To sum up, the quality of the calculated phase image is often poor due to factors such as illumination arrangement, object surface curvature, and sample reflectivity, resulting in low applicability of existing methods and relatively complex arrangement, resulting in low accuracy of phase measurement.
发明内容Contents of the invention
本发明的目的是提供一种自适应散斑干涉测量方法及系统，提高了相位测量的稳定性和适用性。The purpose of the present invention is to provide an adaptive speckle interferometry method and system, which improves the stability and applicability of phase measurement.
为实现上述目的，本发明提供了如下方案：To achieve the above object, the present invention provides the following scheme:
一种自适应散斑干涉测量方法，包括：An adaptive speckle interferometry method, comprising:
基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像；Based on the four-step phase shift algorithm, each phase shift obtains a group of speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and number of exposures of the speckle images of each group of objects to be detected, and obtains four Groups of speckle images, denoted as four groups of reference speckle images;
分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像；Perform image fusion on each group of reference speckle images respectively, and obtain four reference speckle fusion images;
基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像；Based on the four-step phase shift algorithm, each phase shift acquires a set of deformed speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and exposure of each group of deformed speckle images of the object to be detected The number of times, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像；Perform image fusion on each group of contrasting speckle images respectively to obtain four contrasting speckle fusion images;
获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像；Obtain reference speckle fusion images with a set number of groups and comparison speckle fusion images with a set number of groups, each set of reference speckle fusion images includes four reference speckle fusion images, and each set of comparison speckle fusion images includes four contrasting speckle fusion images Speckle fusion image;
分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像；Image fusion is performed on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four speckle fusion images before deformation;
分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图像融合，获得四幅变形后散斑融合图像；Image fusion is performed on the contrasting speckle fusion images corresponding to the phases of the set number of comparison speckle fusion images respectively, and four deformed speckle fusion images are obtained;
基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。Based on parallel computing, the deformation phase of the object to be detected is determined according to four speckle fusion images before deformation and four speckle fusion images after deformation.
可选地，所述基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位，具体包括：Optionally, based on parallel computing, determining the deformation phase of the object to be detected according to four speckle fusion images before deformation and four speckle fusion images after deformation specifically includes:
基于GPU并行计算，根据公式
Figure PCTCN2022133154-appb-000001
计算所述待检测物体变形的相位； Based on GPU parallel computing, according to the formula
Figure PCTCN2022133154-appb-000001
calculating the phase of deformation of the object to be detected;
其中，
Figure PCTCN2022133154-appb-000002
表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。 in,
Figure PCTCN2022133154-appb-000002
Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
可选地，所述参考散斑融合图像表示为：
Figure PCTCN2022133154-appb-000003
Optionally, the reference speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000003
所述对比散斑融合图像表示为：
Figure PCTCN2022133154-appb-000004
The contrastive speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000004
其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的对比散斑融合图像，i∈[1,2,3,4]，
Figure PCTCN2022133154-appb-000005
表示变形前第i次相移后的第k次曝光时的散斑图像，
Figure PCTCN2022133154-appb-000006
表示变形后第i次相移后的第k次曝光时的散斑图像。 Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the comparison speckle fusion image after the i-th phase shift, i ∈[1,2,3,4],
Figure PCTCN2022133154-appb-000005
Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation,
Figure PCTCN2022133154-appb-000006
Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
可选地，一种自适应散斑干涉测量方法还包括：利用计算机控制压电陶瓷产生相位变化实现所述四步相移算法中的四步相移。Optionally, an adaptive speckle interferometry method further includes: using a computer to control piezoelectric ceramics to generate phase changes to implement the four-step phase shift in the four-step phase shift algorithm.
本发明还公开了一种自适应散斑干涉测量系统，包括：The invention also discloses an adaptive speckle interferometry system, including:
四组参考散斑图像获取模块，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像；Four groups of reference speckle image acquisition modules are used to obtain a group of speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate the speckle images of each group of objects to be detected The exposure time and the number of exposures of the speckle images are used to obtain four sets of speckle images, which are recorded as four sets of reference speckle images;
四幅参考散斑融合图像获取模块，用于分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像；The acquisition module of four reference speckle fusion images is used to perform image fusion on each set of reference speckle images respectively to obtain four reference speckle fusion images;
四组对比散斑图像获取模块，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像；Four sets of comparison speckle image acquisition module, used to obtain a set of deformed speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate each group of objects to be detected The exposure time and number of exposures of the deformed speckle image, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
四幅对比散斑融合图像获取模块，用于分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像；The acquisition module of four contrasting speckle fusion images is used to perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images;
设定组数的参考散斑融合图像和对比散斑融合图像获得模块，用于获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像；A reference speckle fusion image with a set number of groups and a comparison speckle fusion image obtaining module, configured to obtain a reference speckle fusion image with a set number of groups and a contrastive speckle fusion image with a set number of groups, and each set of reference speckle fusion images The images all include four reference speckle fusion images, and each group of comparison speckle fusion images includes four comparison speckle fusion images;
变形前散斑融合图像确定模块，用于分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像；The pre-deformation speckle fusion image determination module is used to perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four pre-deformation speckle fusion images;
变形后散斑融合图像确定模块，用于分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图像融合，获得四幅变形后散斑融合图像；The post-deformation speckle fusion image determination module is used to perform image fusion on the comparison speckle fusion images corresponding to the phases in the set number of comparison speckle fusion images respectively, to obtain four post-deformation speckle fusion images;
相位确定模块，用于基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。The phase determination module is configured to determine the deformation phase of the object to be detected based on parallel computing according to four speckle fusion images before deformation and four speckle fusion images after deformation.
可选地，所述相位确定模块，具体包括：Optionally, the phase determination module specifically includes:
相位确定单元，用于基于GPU并行计算，根据公式
Figure PCTCN2022133154-appb-000007
计算 所述待检测物体变形的相位； The phase determination unit is used for GPU-based parallel computing, according to the formula
Figure PCTCN2022133154-appb-000007
calculating the phase of deformation of the object to be detected;
其中，
Figure PCTCN2022133154-appb-000008
表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。 in,
Figure PCTCN2022133154-appb-000008
Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
可选地，所述参考散斑融合图像表示为：
Figure PCTCN2022133154-appb-000009
Optionally, the reference speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000009
所述对比散斑融合图像表示为：
Figure PCTCN2022133154-appb-000010
The contrastive speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000010
其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的对比散斑融合图像，i∈[1,2,3,4]，
Figure PCTCN2022133154-appb-000011
表示变形前第i次相移后的第k次曝光时的散斑图像，
Figure PCTCN2022133154-appb-000012
表示变形后第i次相移后的第k次曝光时的散斑图像。 Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the comparison speckle fusion image after the i-th phase shift, i ∈[1,2,3,4],
Figure PCTCN2022133154-appb-000011
Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation,
Figure PCTCN2022133154-appb-000012
Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
可选地，一种自适应散斑干涉测量系统，还包括：利用计算机控制压电陶瓷产生相位变化实现所述四步相移算法中的四步相移。Optionally, an adaptive speckle interferometry system further includes: using a computer to control piezoelectric ceramics to generate phase changes to implement the four-step phase shift in the four-step phase shift algorithm.
根据本发明提供的具体实施例，本发明公开了以下技术效果：According to the specific embodiments provided by the invention, the invention discloses the following technical effects:
本发明一种自适应散斑干涉测量方法及系统，通过融合不同曝光时间获得的变形前的参考散斑图像和变形后的散斑图像，提高四步相移算法获取不同相位时散斑图像的质量，通过对不同曝光程度的散斑图像进行图像融合，在曝光亮度不均条件下进行自适应散斑干涉测量，从而提高相位测量的稳定性和适用性。An adaptive speckle interferometry method and system according to the present invention, by fusing pre-deformed reference speckle images and deformed speckle images obtained at different exposure times, improves the performance of speckle images obtained by four-step phase shift algorithm at different phases Quality, through image fusion of speckle images with different exposure levels, adaptive speckle interferometry is performed under the condition of uneven exposure brightness, so as to improve the stability and applicability of phase measurement.
附图说明Description of drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。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 accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.
图1为本发明一种自适应散斑干涉测量方法流程示意图；Fig. 1 is a schematic flow chart of an adaptive speckle interferometry method according to the present invention;
图2为本发明一段曝光时间内多张曝光图像强度区域分布特征示意图；Fig. 2 is a schematic diagram of distribution characteristics of multiple exposure image intensity regions within a period of exposure time in the present invention;
图3为本发明HDRPR实时检测方法示意图；Fig. 3 is the schematic diagram of HDRPR real-time detection method of the present invention;
图4为本发明实施例针对试件的试验检测环境示意图；4 is a schematic diagram of the test and detection environment for the test piece according to the embodiment of the present invention;
图5为本发明实施例试验结果示意图；Fig. 5 is the schematic diagram of test result of the embodiment of the present invention;
图6为本发明一种自适应散斑干涉测量系统结构示意图。Fig. 6 is a schematic structural diagram of an adaptive speckle interferometry system according to the present invention.
具体实施方式Detailed ways
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.
本发明的目的是提供一种自适应散斑干涉测量方法及系统，提高了相位测量的稳定性和适用性。The purpose of the present invention is to provide an adaptive speckle interferometry method and system, which improves the stability and applicability of phase measurement.
为使本发明的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本发明作进一步详细的说明。In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
图1为本发明一种自适应散斑干涉测量方法流程示意图，如图1所示，一种自适应散斑干涉测量方法，包括：Fig. 1 is a schematic flow chart of an adaptive speckle interferometry method according to the present invention. As shown in Fig. 1, an adaptive speckle interferometry method includes:
步骤101：基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像。Step 101: Based on the four-step phase shift algorithm, each phase shift acquires a group of speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and number of exposures of the speckle images of each group of objects to be detected , to obtain four sets of speckle images, which are recorded as four sets of reference speckle images.
其中，步骤101具体包括:基于计算机控制压电陶瓷产生相位变化，采用四步相移算法获取待检测物体的四幅参考散斑融合图像。Wherein, step 101 specifically includes: based on the computer controlling the piezoelectric ceramics to generate a phase change, and adopting a four-step phase shift algorithm to obtain four reference speckle fusion images of the object to be detected.
一组待检测物体的散斑图像包括不同曝光程度的散斑图像，随着逐渐增加曝光时间，散斑图像从曝光不足区域大于正常曝光区域到曝光不足区域减少、曝光过度区域增加，直到曝光不足区域减少到0。A set of speckle images of the object to be detected includes speckle images with different exposure levels. As the exposure time gradually increases, the speckle image changes from underexposed areas larger than normal exposure areas to underexposed areas decreasing, overexposed areas increasing, until underexposed The area is reduced to 0.
正常曝光区域为图像灰度值在0到255之间；当图像灰度值大于或等于255时为曝光过度区域，当图像灰度值小于或等于0时为曝光不足区域。The normal exposure area is an image grayscale value between 0 and 255; when the image grayscale value is greater than or equal to 255, it is an overexposed area, and when the image grayscale value is less than or equal to 0, it is an underexposed area.
步骤102：分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像。Step 102: performing image fusion on each set of reference speckle images respectively, to obtain four reference speckle fusion images.
其中，步骤102具体包括：在CPU端分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像。Wherein, step 102 specifically includes: performing image fusion on each set of reference speckle images respectively at the CPU end to obtain four reference speckle fusion images.
步骤103：基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像。Step 103: Based on the four-step phase shift algorithm, each phase shift acquires a set of deformed speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure of each group of deformed speckle images of the object to be detected Time and number of exposures, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images.
一组待检测物体变形后的散斑图像包括不同曝光程度的散斑图像，随着逐渐增加曝光时间，散斑图像从曝光不足区域大于正常曝光区域到曝光不足区域减少、曝光过度区域增加，直到曝光不足 区域减少到0。A set of deformed speckle images of the object to be detected includes speckle images with different exposure levels. As the exposure time gradually increases, the speckle image changes from underexposed areas larger than normal exposure areas to underexposed areas decreasing and overexposed areas increasing until The underexposed areas are reduced to 0.
利用数码相机曝光量和曝光时间之间的关系，根据成像强度的区域分布特征，从短到长标定曝光次数和一组曝光时间。Using the relationship between exposure amount and exposure time of a digital camera, according to the regional distribution characteristics of imaging intensity, the number of exposures and a set of exposure times are calibrated from short to long.
曝光量一般通过数字相机的曝光时间来调整。因为原始图像的选择直接关系到融合质量和计算效率，曝光时间的确定对于图像融合至关重要。由于在散斑图像中经常发现曝光过度或曝光不足的区域是局部斑点，因此散斑图像可以分为三个部分，即正常曝光区域A、曝光过度区域V和曝光不足区域U。The exposure is generally adjusted by the exposure time of the digital camera. Because the selection of original images is directly related to fusion quality and computational efficiency, the determination of exposure time is crucial for image fusion. Since the overexposed or underexposed areas are often found to be local spots in the speckle image, the speckle image can be divided into three parts, namely the normal exposure area A, the overexposed area V and the underexposed area U.
开始多曝光图像采集，相机的曝光时间最初设置为零。在这种情况下，图像在曝光不足的状态下整体较暗。通过逐渐增加曝光时间，视野中的明亮区域变得可见，并随着曝光时间的增加逐渐饱和。就在这种饱和发生之前，确定第一张散斑图像I (1)的相应曝光时间。如图2(a)所示，图像中只有圆圈内区域A (1)正常曝光，其余区域U (1)仍然曝光不足(阴影区域)。随着曝光时间的增加，饱和发生并且饱和区域扩大直到其边界达到A (1)。图2(b)为第二张散斑图像I (2)确定相应的曝光时间。在这种情况下图2(c)，图像被分为三个区域，包括过度曝光区域V (1)、正常曝光区域A (2)和曝光不足区域U (2)。曝光时间不断调整，直到曝光不足区域减少。在这样的程序之后，确定一系列曝光时间。一旦确定了一系列曝光时间，就可以在变形前后获得同一相移步骤的一系列散斑图像。 To start multi-exposure image acquisition, the camera's exposure time is initially set to zero. In this case, the image is overall darker in the underexposed state. By gradually increasing the exposure time, bright areas in the field of view become visible and gradually saturate as the exposure time increases. Just before this saturation occurs, the corresponding exposure time of the first speckle image I (1) is determined. As shown in Figure 2(a), only the area A (1) inside the circle is normally exposed in the image, and the rest of the area U (1) is still underexposed (shaded area). As the exposure time increases, saturation occurs and the saturated region expands until its boundary reaches A (1) . Figure 2(b) determines the corresponding exposure time for the second speckle image I (2) . In this case Fig. 2(c), the image is divided into three regions, including the overexposed region V (1) , the normal exposed region A (2) and the underexposed region U (2) . The exposure time is continuously adjusted until the underexposed areas are reduced. Following such a procedure, a series of exposure times is determined. Once a series of exposure times is determined, a series of speckle images of the same phase shift step can be obtained before and after deformation.
本发明的散斑图像融合为一种高效的稳定的可用于时间相移的图像融合算法。The speckle image fusion of the present invention is an efficient and stable image fusion algorithm that can be used for time phase shift.
本发明采用实时的检测策略：利用计算机控制压电陶瓷控制驱动镜的移动步长，在每一个相移下，根据标准曝光多次，并利用提出的融合算法，融合同一个光场下多个曝光量的散斑图像。为了避免CPU和GPU间频繁的数据交互，图像融合是在CPU端完成的，融合的散斑图像被发送到GPU端，执行滤波和相位计算。本发明采用四步相移，相移范围内从小到大循环，每相移一次，输出一张相位图像。The present invention adopts a real-time detection strategy: use the computer to control the piezoelectric ceramics to control the moving step of the driving mirror, under each phase shift, expose multiple times according to the standard, and use the proposed fusion algorithm to fuse multiple Exposure of the speckle image. In order to avoid frequent data interaction between the CPU and GPU, image fusion is done on the CPU side, and the fused speckle image is sent to the GPU side for filtering and phase calculation. The present invention adopts four-step phase shift, and the phase shift range is cycled from small to large, and a phase image is output for each phase shift.
步骤104：分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像。Step 104: Perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images.
其中，步骤104具体包括：在CPU端分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像。Wherein, step 104 specifically includes: performing image fusion on each group of contrasting speckle images respectively at the CPU end to obtain four contrasting speckle fusion images.
步骤105：获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像。Step 105: Obtain reference speckle fusion images with a set number of groups and comparison speckle fusion images with a set number of groups, each set of reference speckle fusion images includes four reference speckle fusion images, and each set of comparison speckle fusion images Four contrasting speckle fusion images are included.
步骤106：分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像。Step 106: Perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images respectively, to obtain four speckle fusion images before deformation.
步骤107：分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图 像融合，获得四幅变形后散斑融合图像。Step 107: Perform image fusion on the contrasting speckle fusion images of the corresponding phases in the set number of contrasting speckle fusion images, respectively, to obtain four deformed speckle fusion images.
步骤108：基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。Step 108: Based on parallel calculation, determine the deformation phase of the object to be detected according to the four speckle fusion images before deformation and the four speckle fusion images after deformation.
其中，步骤108具体包括：基于GPU并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位；四幅变形后散斑融合图像和四幅变形前散斑融合图像均存放到GPU内存中。Wherein, step 108 specifically includes: based on GPU parallel computing, determining the deformation phase of the object to be detected according to four speckle fusion images before deformation and four speckle fusion images after deformation; four speckle fusion images after deformation and four speckle fusion images before deformation All speckle fusion images are stored in GPU memory.
根据公式
Figure PCTCN2022133154-appb-000013
计算待检测物体变形的相位。 According to the formula
Figure PCTCN2022133154-appb-000013
Calculate the phase of the deformation of the object to be detected.
其中，
Figure PCTCN2022133154-appb-000014
表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。 in,
Figure PCTCN2022133154-appb-000014
Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
参考散斑融合图像表示为：
Figure PCTCN2022133154-appb-000015
The reference speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000015
对比散斑融合图像表示为：
Figure PCTCN2022133154-appb-000016
The contrastive speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000016
其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的对比散斑融合图像，i∈[1,2,3,4]，
Figure PCTCN2022133154-appb-000017
表示变形前第i次相移后的第k次曝光时的散斑图像，
Figure PCTCN2022133154-appb-000018
表示变形后第i次相移后的第k次曝光时的散斑图像。 Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the comparison speckle fusion image after the i-th phase shift, i ∈[1,2,3,4],
Figure PCTCN2022133154-appb-000017
Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation,
Figure PCTCN2022133154-appb-000018
Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
下面详细说明本发明一种自适应散斑干涉测量方法。An adaptive speckle interferometry method of the present invention will be described in detail below.
四步相移计算相位的过程需要记录变形前的四幅图像以及变形后的四幅图像：The process of calculating the phase by four-step phase shift needs to record four images before deformation and four images after deformation:
Figure PCTCN2022133154-appb-000019
Figure PCTCN2022133154-appb-000019
其中，a是散斑图像的背景强度，b是散斑图像的调制项；
Figure PCTCN2022133154-appb-000020
是未知的随机相位；i是相移步骤的序数。I 0i和I 1i分别表示变形前和变形后的散斑图像。
Figure PCTCN2022133154-appb-000021
是编码物体表面变形的参数(相位)，
Figure PCTCN2022133154-appb-000022
的计算公式可由上式求得： Among them, a is the background intensity of the speckle image, and b is the modulation item of the speckle image;
Figure PCTCN2022133154-appb-000020
is the unknown random phase; i is the ordinal number of the phase shift step. I 0i and I 1i denote the speckle image before and after deformation, respectively.
Figure PCTCN2022133154-appb-000021
is the parameter (phase) that encodes the deformation of the surface of the object,
Figure PCTCN2022133154-appb-000022
The calculation formula of can be obtained from the above formula:
Figure PCTCN2022133154-appb-000023
Figure PCTCN2022133154-appb-000023
该技术用于光强分布较合理的情况，具有良好的性能。当光强分布超出允许范围后，相位图像的质量明显下降。本发明在每一次相移步骤下记录多个给定曝光度水平的散斑图像，此时散斑图像强度可描述为：This technology is used in situations where the light intensity distribution is reasonable and has good performance. When the light intensity distribution exceeds the allowable range, the quality of the phase image decreases obviously. The present invention records multiple speckle images with a given exposure level under each phase shift step, and the speckle image intensity at this time can be described as:
Figure PCTCN2022133154-appb-000024
Figure PCTCN2022133154-appb-000024
k是曝光序数；N是总共的曝光次数。当明暗变化较大的表面呈现在相机的视场中时，不同曝光度的散斑图像只能编码图像亮度适当的区域，因此融合不同曝光度的散斑图像可以大幅扩张散斑图像的有效编码区域。实时检测要求融合算法的复杂度应尽量低并能有效计算出高质量的相位图像。所以本发明根据四步相移原理，构造图像融合算法，融合的散斑图像可表示为：k is the exposure sequence number; N is the total number of exposures. When a surface with large changes in brightness and darkness appears in the camera's field of view, speckle images with different exposures can only encode areas with appropriate brightness, so fusing speckle images with different exposures can greatly expand the effective encoding of speckle images area. Real-time detection requires that the complexity of the fusion algorithm should be as low as possible and can effectively calculate high-quality phase images. Therefore, the present invention constructs an image fusion algorithm based on the four-step phase shift principle, and the fused speckle image can be expressed as:
Figure PCTCN2022133154-appb-000025
Figure PCTCN2022133154-appb-000025
由于在测量过程中，光照状态几乎保持不变，且曝光次数和曝光时间是预定义的，可以认为不同曝光度的散斑图像具有单调的关系。Since the illumination state remains almost constant during the measurement process, and the number of exposures and the exposure time are predefined, it can be considered that the speckle images with different exposures have a monotonic relationship.
Figure PCTCN2022133154-appb-000026
Figure PCTCN2022133154-appb-000026
当光强分布处于图像灰度值可表征的动态范围内时，α i,i＝1,2…N是一系列的比例系数。当图像过曝光或欠曝光时，8位的图像灰度值分别是255和0。将式(2)和(3)带入式(1)，从融合的散斑图像计算出的相位可表达为： When the light intensity distribution is within the dynamic range that can be represented by the gray value of the image, α i , i=1, 2...N is a series of proportional coefficients. When the image is overexposed or underexposed, the 8-bit image grayscale values are 255 and 0, respectively. Substituting equations (2) and (3) into equation (1), the phase calculated from the fused speckle image can be expressed as:
Figure PCTCN2022133154-appb-000027
Figure PCTCN2022133154-appb-000027
可以发现，只要控制不同相移步骤下的α i始终对齐，最后的相位计算形式和式(1)是一致 的，所以公式(2)构建的融合算法可用于相位计算。 It can be found that as long as the αi under different phase shift steps are always aligned, the final phase calculation form is consistent with formula (1), so the fusion algorithm constructed by formula (2) can be used for phase calculation.
HDRPR(高动态范围相位重建)将多曝光的散斑图像融合成一张编码更高动态范围相位信息的单个图像，HDRPR一种非接触的光学方法，可应用于光亮表面的亚微米变形检测。该技术相对于传统的方法较为耗时。本发明根据实时检测要求，提出一种稳定有效的实现策略，该策略是一种结合了相机多曝光采图、压电陶瓷控制和CPU-GPU编程的技术方案，GPU主要用于并行计算相位图像，因此在程序执行前，预定义了8块GPU内存，4块用于存放参考图R 0i，4块用于存放变形图R 1i，i＝1,2,3,4。 HDRPR (High Dynamic Range Phase Reconstruction) fuses multiple-exposure speckle images into a single image that encodes higher dynamic range phase information. HDRPR is a non-contact optical method that can be applied to submicron deformation detection on shiny surfaces. This technique is more time-consuming than traditional methods. According to the requirements of real-time detection, the present invention proposes a stable and effective implementation strategy. This strategy is a technical solution that combines multi-exposure image acquisition with cameras, piezoelectric ceramic control and CPU-GPU programming. GPU is mainly used for parallel calculation of phase images. , so before the program is executed, 8 GPU memory blocks are predefined, 4 blocks are used to store the reference image R 0i , and 4 blocks are used to store the deformed image R 1i , i=1,2,3,4.
首先，通过输入特定的直流电压控制压电陶瓷产生π/2的相位变化，相位从小到大在0到3π/2范围内循环。在该相位下，利用步骤1标定的曝光规则多次曝光记录当前光场。基于CPU多线程技术并行技术应用步骤2中的式(2)融合得到一张散斑图像，散斑图像保存在主机端的内存中，此时，拷贝融合的散斑图像到客户端的内存中。测量中该过程不断重复，当客户端内存中同时存在R 0i和R 1i时，i＝1,2,3,4，此时调用GPU应用式(4)计算相位
Figure PCTCN2022133154-appb-000028
CUDA是一种有效的可用于调用GPU的计算平台。利用该平台上，按照一维的形式排列线程块并预定义了与图像分辨率等同的GPU线程束，以确保解相位和滤波的高并发性。计算得到的相位图像复制回主机端分线程实时显示。需要注意的是，在一次测量中，保存R 0i的内存块只更新一次，保存R 1i的内存块循环更新。图3展示了该策略的示意图。 First, the piezoceramic is controlled to produce a phase change of π/2 by inputting a specific DC voltage, and the phase cycles from small to large in the range of 0 to 3π/2. At this phase, use the exposure rule calibrated in step 1 to record the current light field with multiple exposures. Based on the parallel technology of CPU multi-threading technology, the formula (2) in step 2 is fused to obtain a speckle image. The speckle image is stored in the memory of the host. At this time, copy the fused speckle image to the memory of the client. This process is repeated continuously during the measurement. When R 0i and R 1i exist in the client memory at the same time, i=1, 2, 3, 4, at this time, the GPU application formula (4) is called to calculate the phase
Figure PCTCN2022133154-appb-000028
CUDA is an efficient computing platform that can be used to call GPU. On this platform, the thread blocks are arranged in a one-dimensional form and the GPU thread warp equal to the image resolution is predefined to ensure high concurrency of dephasing and filtering. The calculated phase image is copied back to the host and displayed in real-time in a threaded manner. It should be noted that in a measurement, the memory block storing R 0i is only updated once, and the memory block storing R 1i is updated cyclically. Figure 3 presents a schematic diagram of this strategy.
下面以具体实施例说明本发明一种自适应散斑干涉测量方法。An adaptive speckle interferometry method of the present invention will be described below with specific embodiments.
将本发明一种自适应散斑干涉测量方法应用于检测橡胶金属粘接圆柱壳内壁的脱粘缺陷检测，测量过程如下：An adaptive speckle interferometry method of the present invention is applied to detect the debonding defect detection of the inner wall of the rubber-metal bonded cylindrical shell, and the measurement process is as follows:
a)将圆柱壳放置在检测平台上，架设剪切散斑干涉设备于被测物前方。调整探头位姿，直到被测物成像在视场中间(图4)。a) Place the cylindrical shell on the detection platform, and set up the shear speckle interference device in front of the measured object. Adjust the pose of the probe until the object under test is imaged in the middle of the field of view (Figure 4).
b)打开激光器，让激光散斑覆盖被测物。调整相机光圈，焦距，曝光时间，直到被测物清晰成像，并尽量充满相机视场。根据检测经验设置剪切量。b) Turn on the laser and let the laser speckle cover the measured object. Adjust the camera aperture, focal length, and exposure time until the object under test is imaged clearly and fills the field of view of the camera as much as possible. Set the shear amount according to the detection experience.
c)设置最小曝光时间。开始相机曝光量标定流程。曝光标定完成后，开始实时高动态范围相位重建，并刷新参考图。利用卤素灯或热风机，加热试件表面。c) Set the minimum exposure time. Start the camera exposure calibration process. After exposure calibration is completed, start real-time high dynamic range phase reconstruction and refresh the reference image. Use a halogen lamp or a hot air blower to heat the surface of the test piece.
试验结果如图5所示，图5中(a)、(b)和(c)的上方图为散斑图像，下方为对应的相位图像。通过对比可以清晰的看到基于HDRPR计算得到的相位图像，很好的融合了不同曝光度的散斑图像编码的相位信息，并可以实现实时的检测需求。The test results are shown in Figure 5. The upper images of (a), (b) and (c) in Figure 5 are speckle images, and the lower images are the corresponding phase images. Through comparison, it can be clearly seen that the phase image calculated based on HDRPR is well integrated with the phase information encoded by speckle images with different exposures, and can realize real-time detection requirements.
图6为本发明一种自适应散斑干涉测量系统结构示意图，如图6所示，一种自适应散斑 干涉测量系统，包括：Fig. 6 is a schematic structural diagram of an adaptive speckle interferometry system according to the present invention. As shown in Fig. 6, an adaptive speckle interferometry system includes:
四组参考散斑图像获取模块201，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像；The four-group reference speckle image acquisition module 201 is configured to acquire a group of speckle images of the object to be detected according to the exposure time from short to long for each phase shift based on the four-step phase shift algorithm, and calibrate each group of the object to be detected The exposure time and number of exposures of the speckle image, four sets of speckle images are obtained, and recorded as four sets of reference speckle images;
四幅参考散斑融合图像获取模块202，用于分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像；The four reference speckle fusion image acquisition module 202 is configured to perform image fusion on each set of reference speckle images respectively, and acquire four reference speckle fusion images;
四组对比散斑图像获取模块203，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像；The four-group comparison speckle image acquisition module 203 is used to obtain a group of deformed speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate each group of speckle images to be detected The exposure time and number of exposures of the speckle image after the deformation of the object, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
四幅对比散斑融合图像获取模块204，用于分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像；The acquisition module 204 of four contrasting speckle fusion images is configured to perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images;
设定组数的参考散斑融合图像和对比散斑融合图像获得模块205，用于获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像；A reference speckle fusion image with a set number of groups and a comparison speckle fusion image obtaining module 205, configured to obtain a reference speckle fusion image with a set number of groups and a comparison speckle fusion image with a set number of groups, each group of reference speckle fusion The fused images all include four reference speckle fusion images, and each group of contrasting speckle fusion images includes four contrasting speckle fusion images;
变形前散斑融合图像确定模块206，用于分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像；The pre-deformation speckle fusion image determination module 206 is configured to perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four pre-deformation speckle fusion images;
变形后散斑融合图像确定模块207，用于分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图像融合，获得四幅变形后散斑融合图像；Deformed speckle fusion image determination module 207, configured to perform image fusion on contrasting speckle fusion images of corresponding phases in the set number of comparison speckle fusion images respectively, to obtain four deformed speckle fusion images;
相位确定模块208，用于基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。The phase determining module 208 is configured to determine the phase of deformation of the object to be detected based on parallel computing according to four speckle fusion images before deformation and four speckle fusion images after deformation.
相位确定模块208，具体包括：The phase determination module 208 specifically includes:
相位确定单元，用于基于GPU并行计算，根据公式
Figure PCTCN2022133154-appb-000029
计算所述待检测物体变形的相位； The phase determination unit is used for GPU-based parallel computing, according to the formula
Figure PCTCN2022133154-appb-000029
calculating the phase of deformation of the object to be detected;
其中，
Figure PCTCN2022133154-appb-000030
表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。 in,
Figure PCTCN2022133154-appb-000030
Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
参考散斑融合图像表示为：
Figure PCTCN2022133154-appb-000031
The reference speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000031
对比散斑融合图像表示为：
Figure PCTCN2022133154-appb-000032
The contrastive speckle fusion image is expressed as:
Figure PCTCN2022133154-appb-000032
其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的变形后散斑融合图像，i∈[1,2,3,4]，
Figure PCTCN2022133154-appb-000033
表示变形前第i次相移后的第k次曝光时的散斑图像，
Figure PCTCN2022133154-appb-000034
表示变形后第i次相移后的第k次曝光时的散斑图像。 Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the deformed speckle fusion image after the i-th phase shift, i∈[1,2,3,4],
Figure PCTCN2022133154-appb-000033
Indicates the speckle image at the kth exposure after the ith phase shift before deformation,
Figure PCTCN2022133154-appb-000034
Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
一种自适应散斑干涉测量系统，还包括：相位变化驱动模块，用于利用计算机控制压电陶瓷产生相位变化实现所述四步相移算法中的四步相移。An adaptive speckle interferometry system further includes: a phase change driving module, which is used to use a computer to control piezoelectric ceramics to generate phase changes to realize the four-step phase shift in the four-step phase shift algorithm.
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。对于实施例公开的系统而言，由于其与实施例公开的方法相对应，所以描述的比较简单，相关之处参见方法部分说明即可。Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.
本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想；同时，对于本领域的一般技术人员，依据本发明的思想，在具体实施方式及应用范围上均会有改变之处。综上所述，本说明书内容不应理解为对本发明的限制。In this paper, specific examples have been used to illustrate the principle and implementation 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; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in specific implementation methods and application ranges. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

  1. 一种自适应散斑干涉测量方法，其特征在于，包括：An adaptive speckle interferometry method, characterized in that it comprises:
    基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像；Based on the four-step phase shift algorithm, each phase shift obtains a group of speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and number of exposures of the speckle images of each group of objects to be detected, and obtains four Groups of speckle images, denoted as four groups of reference speckle images;
    分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像；Perform image fusion on each group of reference speckle images respectively, and obtain four reference speckle fusion images;
    基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像；Based on the four-step phase shift algorithm, each phase shift acquires a set of deformed speckle images of the object to be detected according to the exposure time from short to long, and calibrates the exposure time and exposure of each group of deformed speckle images of the object to be detected The number of times, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
    分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像；Perform image fusion on each group of contrasting speckle images respectively to obtain four contrasting speckle fusion images;
    获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像；Obtain reference speckle fusion images with a set number of groups and comparison speckle fusion images with a set number of groups, each set of reference speckle fusion images includes four reference speckle fusion images, and each set of comparison speckle fusion images includes four contrasting speckle fusion images Speckle fusion image;
    分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像；Image fusion is performed on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four speckle fusion images before deformation;
    分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图像融合，获得四幅变形后散斑融合图像；Image fusion is performed on the contrasting speckle fusion images corresponding to the phases of the set number of comparison speckle fusion images respectively, and four deformed speckle fusion images are obtained;
    基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。Based on parallel computing, the deformation phase of the object to be detected is determined according to four speckle fusion images before deformation and four speckle fusion images after deformation.
  2. 根据权利要求1所述的自适应散斑干涉测量方法，其特征在于，所述基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位，具体包括：The adaptive speckle interferometry method according to claim 1, wherein the phase of deformation of the object to be detected is determined based on parallel computing based on four speckle fusion images before deformation and four speckle fusion images after deformation , including:
    基于GPU并行计算，根据公式
    Figure PCTCN2022133154-appb-100001
    计算所述待检测物体变形的相位；     Based on GPU parallel computing, according to the formula
    Figure PCTCN2022133154-appb-100001
    calculating the phase of deformation of the object to be detected;
    其中，
    Figure PCTCN2022133154-appb-100002
    表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。     in,
    Figure PCTCN2022133154-appb-100002
    Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  3. 根据权利要求1所述的自适应散斑干涉测量方法，其特征在于，所述参考散斑融合图像表示为：
    Figure PCTCN2022133154-appb-100003
    The adaptive speckle interferometry method according to claim 1, wherein the reference speckle fusion image is expressed as:
    Figure PCTCN2022133154-appb-100003
    所述对比散斑融合图像表示为：
    Figure PCTCN2022133154-appb-100004
    The contrastive speckle fusion image is expressed as:
    Figure PCTCN2022133154-appb-100004
    其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的对比散斑融合图像，i∈[1,2,3,4]，
    Figure PCTCN2022133154-appb-100005
    表示变形前第i次相移后的第k次曝光时的散斑图像，
    Figure PCTCN2022133154-appb-100006
    表示变形后第i次相移后的第k次曝光时的散斑图像。     Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the comparison speckle fusion image after the i-th phase shift, i ∈[1,2,3,4],
    Figure PCTCN2022133154-appb-100005
    Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation,
    Figure PCTCN2022133154-appb-100006
    Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
  4. 根据权利要求1所述的自适应散斑干涉测量方法，其特征在于，还包括：利用计算机控制压电陶瓷产生相位变化实现所述四步相移算法中的四步相移。The adaptive speckle interferometry method according to claim 1, further comprising: using a computer to control piezoelectric ceramics to generate phase changes to realize the four-step phase shift in the four-step phase shift algorithm.
  5. 一种自适应散斑干涉测量系统，其特征在于，包括：An adaptive speckle interferometry system, characterized in that it comprises:
    四组参考散斑图像获取模块，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体的散斑图像，并标定每组待检测物体的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组参考散斑图像；Four groups of reference speckle image acquisition modules are used to obtain a group of speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate the speckle images of each group of objects to be detected The exposure time and the number of exposures of the speckle images are used to obtain four sets of speckle images, which are recorded as four sets of reference speckle images;
    四幅参考散斑融合图像获取模块，用于分别对各组参考散斑图像进行图像融合，获取四幅参考散斑融合图像；The acquisition module of four reference speckle fusion images is used to perform image fusion on each set of reference speckle images respectively to obtain four reference speckle fusion images;
    四组对比散斑图像获取模块，用于基于四步相移算法，每一次相移均按照曝光时间从短到长获取一组待检测物体变形后的散斑图像，并标定每组待检测物体变形后的散斑图像的曝光时间和曝光次数，获取四组散斑图像，记为四组对比散斑图像；Four sets of comparison speckle image acquisition module, used to obtain a set of deformed speckle images of the object to be detected based on the four-step phase shift algorithm, each phase shift according to the exposure time from short to long, and calibrate each group of objects to be detected The exposure time and number of exposures of the deformed speckle image, four sets of speckle images are obtained, which are recorded as four sets of comparison speckle images;
    四幅对比散斑融合图像获取模块，用于分别对各组对比散斑图像进行图像融合，获取四幅对比散斑融合图像；The acquisition module of four contrasting speckle fusion images is used to perform image fusion on each group of contrasting speckle images respectively, and obtain four contrasting speckle fusion images;
    设定组数的参考散斑融合图像和对比散斑融合图像获得模块，用于获得设定组数的参考散斑融合图像和设定组数的对比散斑融合图像，每组参考散斑融合图像均包括四幅参考散斑融合图像，每组对比散斑融合图像均包括四幅对比散斑融合图像；A reference speckle fusion image with a set number of groups and a comparison speckle fusion image obtaining module, configured to obtain a reference speckle fusion image with a set number of groups and a contrastive speckle fusion image with a set number of groups, and each set of reference speckle fusion images The images all include four reference speckle fusion images, and each group of comparison speckle fusion images includes four comparison speckle fusion images;
    变形前散斑融合图像确定模块，用于分别对设定组数参考散斑融合图像中对应相位的参考散斑融合图像进行图像融合，获得四幅变形前散斑融合图像；The pre-deformation speckle fusion image determination module is used to perform image fusion on the reference speckle fusion images corresponding to the phases in the set number of reference speckle fusion images, respectively, to obtain four pre-deformation speckle fusion images;
    变形后散斑融合图像确定模块，用于分别对设定组数对比散斑融合图像中对应相位的对比散斑融合图像进行图像融合，获得四幅变形后散斑融合图像；The post-deformation speckle fusion image determination module is used to perform image fusion on the comparison speckle fusion images corresponding to the phases in the set number of comparison speckle fusion images respectively, to obtain four post-deformation speckle fusion images;
    相位确定模块，用于基于并行计算，根据四幅变形前散斑融合图像和四幅变形后散斑融合图像确定所述待检测物体变形的相位。The phase determination module is configured to determine the deformation phase of the object to be detected based on parallel computing according to four speckle fusion images before deformation and four speckle fusion images after deformation.
  6. 根据权利要求5所述的自适应散斑干涉测量系统，其特征在于，所述相位确定模块，具体包括：The adaptive speckle interferometry system according to claim 5, wherein the phase determination module specifically includes:
    相位确定单元，用于基于GPU并行计算，根据公式
    Figure PCTCN2022133154-appb-100007
    计算所述待检测物体变形的相位；     The phase determination unit is used for GPU-based parallel computing, according to the formula
    Figure PCTCN2022133154-appb-100007
    calculating the phase of deformation of the object to be detected;
    其中，
    Figure PCTCN2022133154-appb-100008
    表示所述待检测物体变形的相位，R 01表示变形前第一次相移对应的散斑融合图像，R 02表示变形前第二次相移对应的散斑融合图像，R 03表示变形前第三次相移对应的散斑融合图像，R 04表示变形前第四次相移对应的散斑融合图像，R 11表示变形后第一次相移对应的散斑融合图像，R 12表示变形后第二次相移对应的散斑融合图像，R 13表示变形后第三次相移对应的散斑融合图像，R 14表示变形后第四次相移对应的散斑融合图像。     in,
    Figure PCTCN2022133154-appb-100008
    Indicates the phase of the deformation of the object to be detected, R 01 represents the speckle fusion image corresponding to the first phase shift before deformation, R 02 represents the speckle fusion image corresponding to the second phase shift before deformation, R 03 represents the first phase shift before deformation The speckle fusion image corresponding to three phase shifts, R 04 represents the speckle fusion image corresponding to the fourth phase shift before deformation, R 11 represents the speckle fusion image corresponding to the first phase shift after deformation, R 12 represents the speckle fusion image after deformation The speckle fusion image corresponding to the second phase shift, R 13 represents the speckle fusion image corresponding to the third phase shift after deformation, and R 14 represents the speckle fusion image corresponding to the fourth phase shift after deformation.
  7. 根据权利要求5所述的自适应散斑干涉测量系统，其特征在于，所述参考散斑融合图像表示为：
    Figure PCTCN2022133154-appb-100009
    The adaptive speckle interferometry system according to claim 5, wherein the reference speckle fusion image is expressed as:
    Figure PCTCN2022133154-appb-100009
    所述对比散斑融合图像表示为：
    Figure PCTCN2022133154-appb-100010
    The contrastive speckle fusion image is expressed as:
    Figure PCTCN2022133154-appb-100010
    其中，k表示曝光序数，N 1和N 2均表示曝光次数，R 0i表示第i次相移后的参考散斑融合图像，R 1i表示第i次相移后的对比散斑融合图像，i∈[1,2,3,4]，
    Figure PCTCN2022133154-appb-100011
    表示变形前第i次相移后的第k次曝光时的散斑图像，
    Figure PCTCN2022133154-appb-100012
    表示变形后第i次相移后的第k次曝光时的散斑图像。     Among them, k represents the exposure sequence number, N 1 and N 2 both represent the number of exposures, R 0i represents the reference speckle fusion image after the i-th phase shift, R 1i represents the comparison speckle fusion image after the i-th phase shift, i ∈[1,2,3,4],
    Figure PCTCN2022133154-appb-100011
    Indicates the speckle image at the k-th exposure after the i-th phase shift before deformation,
    Figure PCTCN2022133154-appb-100012
    Denotes the speckle image at the k-th exposure after the i-th phase shift after deformation.
  8. 根据权利要求5所述的自适应散斑干涉测量系统，其特征在于，还包括：利用计算机控制压电陶瓷产生相位变化实现所述四步相移算法中的四步相移。The adaptive speckle interferometry system according to claim 5, further comprising: using a computer to control piezoelectric ceramics to generate phase changes to realize the four-step phase shift in the four-step phase shift algorithm.
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