Discontinuous region phase unwrapping method and apparatus

Abstract

The present application relates to the field of phase measurement, and discloses a discontinuous region phase unwrapping method and device, which is used for effectively unwrapping the phase jump region with phase exceeding 2pi.The method comprises the following steps: obtaining a multi-step fringe pattern formed by multi-step phase shift fringe light projected on an object to be measured; calculating an initial wrapped phase pattern according to the multi-step fringe pattern, and calculating a phase quality map according to the initial wrapped phase pattern, and calculating an edge vector according to the phase quality map; calculating a background light intensity map according to the multi-step fringe pattern, and calculating a horizontal direction light distance phase difference map and a vertical direction light distance phase difference map according to the background light intensity map; and unwrapping the wrapped phase by using the phase quality map, the edge vector, the horizontal direction light distance phase difference map and the vertical direction light distance phase difference map to guide the unwrapping, so as to obtain a discontinuous region phase unwrapping pattern.

Description

Technical Field

[0001] This invention relates to the field of phase measurement technology, and in particular to a method and apparatus for phase unfolding in discontinuous regions. Background Technology

[0002] Phase unwrapping is a key technique in phase measurement profilometry, and the accuracy of phase unwrapping determines the precise reconstruction of the 3D topography. Traditional phase unwrapping techniques are mainly divided into multi-frequency phase unwrapping and single-frequency spatial phase unwrapping. The multi-frequency approach can effectively unwrap the phase of complex topography, but it requires acquiring a large number of fringe images, which is time-consuming and not suitable for measurements in dynamic and fast-paced scenes. The single-frequency approach uses spatial phase unwrapping technology, which only requires acquiring fringe images of a single frequency. The phase unwrapping process requires integration over adjacent pixel paths, and it cannot successfully unwrap the phase in regions with phase discontinuities caused by abrupt changes or jumps.

[0003] Therefore, existing technologies still need improvement and development. Summary of the Invention

[0004] This invention provides a method and apparatus for phase unfolding of discontinuous regions, enabling accurate phase unfolding of isolated, discontinuous object surfaces without the use of additional auxiliary light, and for phase unfolding exceeding... The transition region can still undergo effective phase unfolding.

[0005] The first aspect of the present invention provides a phase unwrapping method for discontinuous regions, the phase unwrapping method for discontinuous regions comprising: Acquire the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test; An initial wrapping phase map is calculated based on the multi-step fringe map, a phase quality map is calculated based on the initial wrapping phase map, and a side vector is calculated based on the phase quality map. The background light intensity map is calculated based on the multi-step fringe map, and the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map are calculated based on the background light intensity map. The phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map are used to guide the unfolding of the wrapped phase, resulting in a phase unfolding map of the discontinuous region.

[0006] Preferably, the step of acquiring the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test includes: A 3D reconstruction system was built using cameras, light sources, and computers; The light source is controlled to generate multi-step phase-shifted fringe light and projected onto the surface of the object under test; The camera acquires a multi-step fringe pattern formed by projecting the multi-step phase-shifting fringe light onto the object under test.

[0007] Preferably, the step of using the phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map to guide the unfolding of the wrapped phase and obtain a discontinuous region phase unfolding map further includes: using the discontinuous region phase unfolding map and preset phase measurement profilometry system parameters to calculate and reconstruct the three-dimensional shape of the object under test.

[0008] Preferably, the background light intensity map Represented as:

[0009] In the formula, express The reflectivity of the morphology, Point Distance to the baseline plane, Indicates the system light intensity coefficient. Indicates background light. This indicates a multi-step stripe pattern at points. The light intensity at that location.

[0010] Preferably, the horizontal illumination distance phase difference diagram Represented as:

[0011] In the formula, This represents the spatial frequency of the fringe pattern on the surface of an object. Indicates the distance between the light source and the camera. Represents two horizontal points and boundary values, Represented as: .

[0012] Preferably, the vertical direction illumination distance phase difference diagram Represented as:

[0013] In the formula, This represents the spatial frequency of the fringe pattern on the surface of an object. Indicates the distance between the light source and the camera. Indicates two points perpendicular to each other. and boundary values, Represented as: .

[0014] Preferably, the step of using the phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map to collaboratively guide the unfolding of the wrapped phase to obtain a phase unfolded map of discontinuous regions includes: performing thresholding processing on the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map to extract regions with large phase differences, obtaining a jump phase mask map; performing contour lookup on the jump phase mask map and dividing it into multiple sub-regions, calculating the wrapped phase value of each sub-region; using the phase quality map and edge vector to perform quality-guided phase unfolding on the wrapped phase values ​​of each sub-region, obtaining unfolded phase maps of multiple sub-regions; finding the phase difference corresponding to the position of 1 in the jump phase mask map in the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map, using this phase difference as the phase difference between each sub-region, and fusing the unfolded phase maps of each sub-region according to the phase difference between each sub-region to obtain a phase unfolded map of discontinuous regions.

[0015] Preferably, the phase transition mask diagram Represented as:

[0016]

[0017] In the formula, Indicates the threshold. This represents the mask generated by the phase difference map of the illumination distance in the horizontal direction. This represents the mask generated by the phase difference map of the vertical illumination distance. This indicates the operation of taking the absolute value.

[0018] Preferably, the step of performing contour lookup on the phase-jumping mask image and dividing it into multiple sub-regions, and calculating the wrapping phase value of each sub-region, includes: extracting edge information of the phase-jumping mask image using the Canny edge detection algorithm; finding the contour information of the phase-jumping mask image based on the extracted edge information; dividing the phase-jumping mask image into multiple sub-regions based on the contour information of the phase-jumping mask image, and calculating the wrapping phase value of each sub-region.

[0019] A second aspect of the present invention provides a discontinuous region phase unfolding device, comprising: an acquisition module for acquiring a multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto a test object; a first calculation module for calculating an initial wrapped phase pattern based on the multi-step fringe pattern, calculating a phase quality pattern based on the initial wrapped phase pattern, and calculating a side vector based on the phase quality pattern; a second calculation module for calculating a background light intensity pattern based on the multi-step fringe pattern, and calculating a horizontal illumination distance phase difference pattern and a vertical illumination distance phase difference pattern based on the background light intensity pattern; and a phase unfolding module for using the phase quality pattern, the side vector, the horizontal illumination distance phase difference pattern, and the vertical illumination distance phase difference pattern to collaboratively guide the unfolding of the wrapped phase, thereby obtaining a discontinuous region phase unfolding pattern.

[0020] The technical solution provided by this invention requires only a single frequency stripe and, without the use of additional auxiliary light, can achieve accurate phase unfolding of isolated, discontinuous object surfaces, and can also perform phase unfolding for surfaces exceeding [a certain frequency]. Even in the transition region, effective phase unfolding can still be performed. This method can effectively expand the application scenarios of spatial phase unfolding algorithm in complex morphology and improve the measurement capability of phase measurement profilometry in fast scenarios. Attached Figure Description

[0021] Figure 1 A flowchart of a phase unfolding method for discontinuous regions provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a three-dimensional reconstruction system for the discontinuous region phase unfolding method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the phase quality edge diagram and the relationship between the edges provided in an embodiment of the present invention; Figure 4 The step-like steep deformation morphology to be tested is provided in an embodiment of the present invention; Figure 5 (a), (b), (c) and (d) in the figure are four-step fringe patterns formed by projecting four-step phase-shifting fringe light onto the object under test according to the embodiments of the present invention; Figure 6 An initial package phase map provided for an embodiment of the present invention; Figure 7 Background light intensity map provided for embodiments of the present invention; Figure 8 A phase difference diagram of horizontal illumination distance provided in an embodiment of the present invention; Figure 9 A phase difference diagram of vertical illumination distance provided in an embodiment of the present invention; Figure 10 This is a phase transition mask diagram provided in an embodiment of the present invention; Figure 11 (a), (b), (c), (d), and (e) in the figure are the unfolded phase diagrams of the plurality of sub-regions provided in the embodiments of the present invention; Figure 12 A phase unfolding diagram of discontinuous regions provided in an embodiment of the present invention; Figure 13 This is a schematic diagram of the discontinuous region phase unfolding device provided in an embodiment of the present invention. Detailed Implementation

[0022] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] For ease of understanding, the specific process of the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 1 An embodiment of the phase unwrapping method for discontinuous regions in this invention includes: S101. Obtain the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test. S102. Calculate the initial wrapped phase map based on the multi-step fringe map, calculate the phase quality map based on the initial wrapped phase map, and calculate the edge vector based on the phase quality map. S103. Calculate the background light intensity map based on the multi-step fringe map, and calculate the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map based on the background light intensity map. S104. Using the phase quality map, edge vector, horizontal illumination distance phase difference map and vertical illumination distance phase difference map to guide the unfolding of the wrapped phase, a phase unfolding map of the discontinuous region is obtained.

[0024] It is understood that the executing entity of this invention can be a phase unfolding device for discontinuous regions, or it can be a terminal or a server; no specific limitation is made here. This embodiment of the invention will be described using a server as an example.

[0025] In this embodiment, step S101, acquiring the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test, includes: building a three-dimensional reconstruction system using a camera, a light source, and a computer (such as...). Figure 2 (As shown); control the light source to generate multi-step phase-shifting fringe light and project it onto the surface of the object under test; use a camera to acquire the multi-step fringe pattern formed by the multi-step phase-shifting fringe light projected onto the object under test.

[0026] In this embodiment, the light source can be a projector.

[0027] In this embodiment, the multi-step phase-shifting stripe light can be a three-step phase-shifting stripe light, a four-step phase-shifting stripe light, or a five-step phase-shifting stripe light, etc.

[0028] In this embodiment, the multi-step stripe pattern is at the point Light intensity at the location Represented as: Formula (1) In the formula, express The reflectivity of the morphology, Point Distance to the baseline plane, Indicates the system light intensity coefficient. Indicates background light. Indicates contrast. This indicates the fringe frequency.

[0029] According to the inverse square law of light attenuation, the intensity of fringe light received by a certain area on the surface of an object is inversely proportional to the square of the distance from that area to the light source.

[0030] Based on the fundamental principles of phase profilometry, the approximate relationship between phase and height can be expressed as: Formula (2) In the formula, This represents the phase difference between point C and point D. This represents the spatial frequency of the fringe pattern on the surface of an object. This represents the distance between the light source and the camera. It can be determined that there is a magnification ratio between height and phase in the system. , Represented as: Formula (3).

[0031] In this embodiment, in step S102, the initial wrapping phase map is represented by the arctangent function:

[0032] Formula (4).

[0033] There are many methods to calculate the phase quality map from the initial package phase map, including pseudo-correlation quality map, phase derivative deviation quality map, and maximum phase gradient quality map. In the phase quality map, the higher the quality value of a point, the higher the phase accuracy. In algorithms that rely on path-based phase unrolling, unrolling is given priority.

[0034] Furthermore, phase quality maps can be used. The phase quality sidemap is constructed by analyzing the differences between adjacent pixels. This sidemap guides the phase unfolding process. The phase quality sidemap consists of vertical and horizontal quality sidemaps. There are many ways to calculate the phase quality sidemap, a simple and fast method being to average the values ​​of vertically or horizontally adjacent quality points. The calculation yields vertical and horizontal quality sidemaps, and the edge values ​​and corresponding position values ​​of these sidemaps are arranged in descending order and placed into the edge vector. For details on the phase-mass sidemap and the relationship between the edges, please refer to [link / reference]. Figure 3 .

[0035] In this embodiment, in step S103, the formula for summing the light intensity of the multi-step fringe pattern is expressed as: Formula (5).

[0036] Since the continuous integral of the cosine function over one period is 0, it is easy to conclude that the discrete integral of the cosine function over a single period is approximately 0. Therefore, the formula for summing the light intensity of a multi-step fringe pattern can be simplified to:

[0037]

[0038] Formula (6).

[0039] Therefore, the background intensity map is obtained by averaging the light intensity of the multi-step fringe pattern. Background light intensity map Represented as: Formula (7).

[0040] In this embodiment, the illumination distance mapping sidemap is used to characterize the geometry of an object and its surface reflection characteristics under illumination conditions. The illumination distance mapping sidemap can be constructed by comparing the illumination intensity between two adjacent pixels. The illumination distance mapping sidemap includes an illumination distance mapping horizontal sidemap. and illumination distance mapping vertical edge graph .

[0041] Light distance mapping horizontal side graph The calculation method and illumination distance mapping vertical edge graph The calculation method is the same; the following uses the illumination distance to map the horizontal edge map. The calculation method will be explained using an example.

[0042] Two horizontal points and The boundary values ​​are obtained by calculating the ratio between the two points; therefore, Represented as:

[0043] Formula (8).

[0044] When measuring the same object, the surface reflectivity of adjacent regions of the object remains almost constant. Therefore, the above formula (8) can be simplified to: Formula (9).

[0045] On point and points There are When there is a height difference, there is Substituting formula (2) into formula (9), we obtain formula (10), which is: Formula (10) In the formula, This represents the phase difference in horizontal illumination distance between two adjacent points.

[0046] Because the change in height on the object's surface is much smaller than the measured distance. Distance can be measured This means that formula (10) can be transformed into formula (11), which is:

[0047] Formula (11) In the formula, This represents a phase difference diagram showing the distance between the horizontal and central illumination points. This represents the spatial frequency of the fringe pattern on the surface of an object. The distance between the light source and the camera is represented by formula (11). It can be seen that the phase difference between two adjacent points is related to the illumination distance mapping side graph, and the horizontal illumination distance phase difference graph calculated by this method is also related to the phase difference between the light source and the camera. Not wrapped in Therefore, the horizontal illumination distance phase difference map generated by the illumination distance mapping sidemap is between [the two points]. Phase difference diagram of illumination distance in the vertical direction It has significant auxiliary value for phase expansion in isolated and discontinuous regions.

[0048] Understandably, the illumination distance maps to the vertical edge graph. It uses two perpendicular points and The boundary value calculation is obtained , Represented as:

[0049] Formula (12).

[0050] Vertical illumination distance phase difference diagram Represented as: Formula (13) . In this embodiment, step S104, which uses the phase quality map, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map to guide the unfolding of the packaged phase and obtain the discontinuous region phase unfolding map, specifically includes: Step S1041, using the horizontal illumination distance phase difference map Phase difference diagram of illumination distance in the vertical direction Thresholding is performed to extract regions with large phase differences, resulting in a phase transition mask image. ; Specifically, the threshold is taken as At that time, the phase difference diagram of the horizontal illumination distance is obtained according to formulas (14) and (15). Phase difference diagram of illumination distance in the vertical direction Thresholding is performed separately.

[0051] Formula (14) Formula (15) In the formula, This represents the mask generated by the phase difference map of the horizontal illumination distance. This represents the mask generated by the phase difference map of the vertical illumination distance. This indicates the operation of taking the absolute value.

[0052] Phase transition mask Represented as: Formula (16) It should be noted that phase transition mask is a technique used in digital image processing and computer vision to describe phase transitions in an image.

[0053] Step S1042, adjust the phase transition mask diagram. Perform contour lookup and divide the region into multiple sub-regions, then calculate the wrap phase value for each sub-region.

[0054] Specifically, the edge information of the phase-jumping mask is extracted using the Canny edge detection algorithm. Then, the contour information of the phase-jumping mask is found based on the extracted edge information. The phase-jumping mask is divided into multiple sub-regions based on the contour information of the phase-jumping mask, and the wrapping phase value of each sub-region is calculated.

[0055] Step S1043: Use the phase quality map and edge vectors to perform quality-guided phase expansion on the wrapping phase values ​​of each sub-region to obtain the expanded phase map of multiple sub-regions.

[0056] Specifically, a quality-oriented phase expansion algorithm (such as least squares phase expansion or Goldstein phase expansion algorithm) is applied to perform quality-oriented phase expansion to obtain the expanded phase map of each sub-region.

[0057] During the phase unfolding process, the wrapped phase can be unfolded one by one according to the edge values ​​and corresponding position values ​​of the vertical mass edge graph and the horizontal mass edge graph recorded in the edge vector.

[0058] Step S1044: Locate the horizontal illumination distance phase difference map. Phase difference diagram of illumination distance in the vertical direction In the transition phase mask diagram The phase difference corresponding to the position 1 is used as the phase difference between each sub-region. The unfolded phase maps of each sub-region are fused according to the phase difference between each sub-region to obtain the phase unfolded map of the discontinuous region.

[0059] In other words, the phase difference diagram of illumination distance in the horizontal direction and the phase difference diagram of illumination distance in the vertical direction. In the transition phase mask diagram The position with a value of 1 is the boundary position of each sub-region.

[0060] When fusing the unfolded phase maps of each sub-region based on the phase difference between them, methods such as weighted averaging of phase differences, interpolation, and boundary transition processing can be used to ensure that the unfolded phase maps of different sub-regions can be smoothly fused together.

[0061] Specifically, as an example, please refer to Figures 4-9 , Figure 4 The image shows the steep deformation morphology of the step to be tested. Figure 5 The four-step fringe pattern is formed by projecting four-step phase-shifting fringe light onto the object under test. Figure 6 The initial wrapping phase map is based on... Figure 5 The multi-step fringe pattern was calculated. Figure 7 This is the background light intensity map, based on... Figure 5 The multi-step stripe pattern was calculated; Figure 8This is a phase difference diagram of illumination distance in the horizontal direction, based on... Figure 7 The background light intensity map was calculated from the image. Figure 9 This is a phase difference diagram of illumination distance in the vertical direction, based on... Figure 7 The background light intensity map was calculated from the image. Figure 10 It is a phase transition mask diagram, based on Figure 8 Horizontal illumination distance phase difference diagram and Figure 9 The vertical direction illumination distance phase difference map is obtained by superimposing the map. Figure 11 To perform quality-guided phase unwrapping on the wrapper phase values ​​of each sub-region using the phase quality map and edge vectors, the unwrapped phase maps of multiple sub-regions are obtained; Figure 12 To fuse the unfolded phase maps of each sub-region based on the phase difference between each sub-region, a phase unfolded map of the discontinuous region is obtained.

[0062] In some embodiments, the discontinuous region phase unfolding method further includes: S105, using the discontinuous region phase unfolding map and preset phase measurement profilometry system parameters to reconstruct the three-dimensional shape of the object under test.

[0063] This embodiment provides a phase unwrapping method for discontinuous regions. It requires only a single-frequency fringe and, without the use of additional auxiliary light, can achieve accurate phase unwrapping of isolated, discontinuous object surfaces, and can handle phases exceeding... Even in the transition region, effective phase unfolding can still be performed. This method can effectively expand the application scenarios of spatial phase unfolding algorithm in complex morphology and improve the measurement capability of phase measurement profilometry in fast scenarios.

[0064] The discontinuous region phase unfolding method in the embodiments of the present invention has been described above. The apparatus in the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 13 The embodiments of the discontinuous region phase unfolding device in this invention include: The acquisition module 201 is used to acquire the multi-step fringe pattern formed by the projection of multi-step phase-shifting fringe light onto the object under test; The first calculation module 202 is used to calculate an initial wrapping phase map based on the multi-step fringe map, calculate a phase quality map based on the initial wrapping phase map, and calculate a side vector based on the phase quality map. The second calculation module 203 is used to calculate the background light intensity map based on the multi-step fringe map, and to calculate the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map based on the background light intensity map. The phase unfolding module 204 is used to guide the unfolding of the wrapped phase in coordination with the phase quality map, the edge vector, the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map to obtain a phase unfolding map of discontinuous regions.

[0065] In this embodiment, accurate phase unfolding of isolated, discontinuous object surfaces can be achieved without the use of additional auxiliary light, and phase unfolding can be performed on surfaces exceeding [a certain threshold]. The transition region can still be effectively phase-expanded, thus effectively expanding the application scenarios of spatial phase-expanding algorithms in complex morphological scenarios and improving the measurement capability of phase measurement profilometry in fast scenarios.

[0066] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system or device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0067] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0068] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phase unwrapping method for discontinuous regions, characterized in that, The discontinuous region phase unwrapping method includes: Acquire the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test; An initial wrapping phase map is calculated based on the multi-step fringe map, a phase quality map is calculated based on the initial wrapping phase map, and a side vector is calculated based on the phase quality map. The background light intensity map is calculated based on the multi-step fringe map, and the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map are calculated based on the background light intensity map. The phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map are used to guide the unfolding of the wrapped phase, resulting in a phase unfolding map of the discontinuous region.

2. The phase unfolding method for discontinuous regions according to claim 1, characterized in that, The acquisition of the multi-step fringe pattern formed by projecting multi-step phase-shifting fringe light onto the object under test includes: A 3D reconstruction system was built using cameras, light sources, and computers; The light source is controlled to generate multi-step phase-shifted fringe light and projected onto the surface of the object under test; The camera acquires a multi-step fringe pattern formed by projecting the multi-step phase-shifting fringe light onto the object under test.

3. The phase unfolding method for discontinuous regions according to claim 2, characterized in that, The method of using the phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map to guide the unfolding of the wrapped phase and obtain a phase unfolding map of the discontinuous region also includes: using the phase unfolding map of the discontinuous region and preset phase measurement profilometry system parameters to calculate and reconstruct the three-dimensional shape of the object under test.

4. The phase unfolding method for discontinuous regions according to claim 1, characterized in that, The background light intensity map Represented as: In the formula, express The reflectivity of the morphology, Point Distance to the baseline plane, Indicates the system light intensity coefficient. Indicates background light. This indicates a multi-step stripe pattern at points. The light intensity at that location.

5. The discontinuous region phase unfolding method according to claim 4, characterized in that, The horizontal illumination distance phase difference diagram Represented as: In the formula, This represents the spatial frequency of the fringe pattern on the surface of an object. Indicates the distance between the light source and the camera. Represents two horizontal points and boundary values, This indicates the magnification between height and phase. Represented as: 。 6. The phase unfolding method for discontinuous regions according to claim 5, characterized in that, The vertical direction illumination distance phase difference diagram Represented as: In the formula, This represents the spatial frequency of the fringe pattern on the surface of an object. Indicates the distance between the light source and the camera. Indicates two points perpendicular to each other. and boundary values, Represented as: 。 7. The discontinuous region phase unfolding method according to claim 6, characterized in that, The method of using the phase quality map, the edge vector, the horizontal illumination distance phase difference map, and the vertical illumination distance phase difference map to collaboratively guide the unfolding of the wrapped phase, resulting in a phase unfolding map of discontinuous regions, includes: Thresholding is performed using the horizontal and vertical illumination distance phase difference maps to extract regions with large phase differences, resulting in a phase transition mask map. The phase transition mask image is contour-finding and divided into multiple sub-regions. The wrapping phase value of each sub-region is calculated. The phase quality map and edge vectors are used to perform quality-guided phase expansion on the wrapping phase values ​​of each sub-region to obtain the expanded phase map of multiple sub-regions; Find the phase difference corresponding to the position where the phase transition mask is 1 in the horizontal and vertical illumination distance phase difference maps. Use this phase difference as the phase difference between each sub-region. Based on the phase difference between each sub-region, fuse the unfolded phase maps of each sub-region to obtain the phase unfolded map of the discontinuous region.

8. The discontinuous region phase unfolding method according to claim 7, characterized in that, The phase transition mask Represented as: In the formula, Indicates the threshold. This represents the mask generated by the phase difference map of the horizontal illumination distance. This represents the mask generated by the phase difference map of the vertical illumination distance. This indicates the operation of taking the absolute value.

9. The phase unfolding method for discontinuous regions according to claim 7, characterized in that, The process of contour finding of the phase transition mask image, dividing it into multiple sub-regions, and calculating the wrap-around phase value of each sub-region includes: The edge information of the phase transition mask image is extracted using the Canny edge detection algorithm; The contour information of the phase transition mask is found based on the extracted edge information; The phase transition mask is divided into multiple sub-regions based on the contour information of the phase transition mask, and the wrapping phase value of each sub-region is calculated.

10. A phase unfolding device for discontinuous regions, characterized in that, include: The acquisition module is used to acquire the multi-step fringe pattern formed by multi-step phase-shifting fringe light projected onto the object under test. The first calculation module is used to calculate an initial wrapped phase map based on the multi-step stripe map, calculate a phase quality map based on the initial wrapped phase map, and calculate a side vector based on the phase quality map. The second calculation module is used to calculate the background light intensity map based on the multi-step fringe map, and to calculate the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map based on the background light intensity map. The phase unfolding module is used to guide the unfolding of the wrapped phase in coordination with the phase quality map, the edge vector, the horizontal illumination distance phase difference map and the vertical illumination distance phase difference map to obtain a phase unfolding map of discontinuous regions.

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