Three-dimensional measurement method and system

Abstract

The application provides a three-dimensional measurement method and system. After an electronic device obtains multiple reflection images of an object surface, in addition to determining full-field phase information through the multiple reflection images, light intensity modulation information is determined according to the multiple reflection images, and the full-field phase information is filtered according to a filtering parameter determined according to the light intensity modulation information. Finally, the three-dimensional information of the object surface is determined using the filtered full-field phase information, thereby reducing the noise in the full-field phase information, avoiding the noise contained in the full-field phase information due to external interference factors, and further improving the measurement accuracy and stability when performing three-dimensional measurement.

Description

Technical Field

[0001] This application relates to the field of image processing technology, and in particular to a three-dimensional measurement method and system. Background Technology

[0002] In 3D Automatic Optic Inspection (3D AOI) technology, 3DAOI technology uses optical projection to non-contactly inspect the three-dimensional data of an object's surface.

[0003] In existing technologies, three-dimensional measurement is achieved by electronic devices. The electronic devices first project a sinusoidal phase-shifted fringe image onto the surface of an object through a transmitting device, and then acquire the image of the object's surface through a data acquisition device. Since the unevenness of the object's surface causes light to bend, the phase-shifted fringe image acquired by the data acquisition device includes information on the deformation of the object's surface. The full-field phase information determined by the electronic devices based on the phase-shifted fringe image can be used to further determine information such as the location and height of the unevenness of the surface.

[0004] Using existing technologies, the phase information of the entire field contains a large amount of noise due to various interference factors such as ambient light, vibration, and thermal noise during the operation of the transmitting and acquiring devices, which reduces the measurement accuracy and stability when performing three-dimensional measurements. Summary of the Invention

[0005] This application provides a three-dimensional measurement method and system to overcome the impact of noise included in the full-field phase information on the measurement accuracy and stability of three-dimensional measurements.

[0006] A first aspect of this application provides a three-dimensional measurement method, comprising: sequentially projecting multiple projection images onto the surface of an object to be detected using visible light, wherein each projection image includes multiple sinusoidal fringes; acquiring multiple reflection images obtained by the surface of the object to be detected reflecting light from the multiple projection images; determining full-field phase information and light intensity modulation information corresponding to the multiple reflection images based on the sinusoidal fringes of the multiple reflection images; filtering the full-field phase information using filtering parameters determined based on the light intensity modulation information; and determining the three-dimensional information of the surface of the object to be detected based on the filtered full-field phase information.

[0007] In one embodiment of the first aspect of this application, the step of filtering the full-field phase information using filtering parameters determined according to the intensity modulation information includes: transforming the full-field phase information from phase space to intensity space to obtain intensity space information of the full-field phase information; determining filtering parameters according to the intensity modulation information; using the filtering parameters to filter the intensity space information to obtain filtering response information of the full-field phase information in the intensity space; and transforming the filtering response information from intensity space to phase space to obtain the filtering result of the full-field phase information.

[0008] In one embodiment of the first aspect of this application, determining the filtering parameters based on the light intensity modulation information includes: determining the filtering parameters based on the relationship between the value of each element in the light intensity modulation information and a preset threshold; the filtering parameters include: a filtering mask matrix, wherein the elements in the filtering mask matrix are used to indicate whether to perform masking processing on the corresponding elements in the light intensity spatial information.

[0009] In one embodiment of the first aspect of this application, determining the filtering parameters based on the relationship between the value of each element in the light intensity modulation information and a preset threshold includes: taking the position of the element in the light intensity modulation information whose value is greater than or equal to the preset threshold as the position of element 1 in the filtering mask matrix; and taking the position of the element in the light intensity modulation information whose value is less than the preset threshold as the position of element 0 in the filtering mask matrix.

[0010] In one embodiment of the first aspect of this application, the step of using the filtering parameters to filter the light intensity spatial information to obtain the filtered response information of the full-field phase information within the light intensity space includes: taking each element in the full-field phase information as the center of the filtering kernel, obtaining multiple elements in the full-field phase information within a preset size corresponding to each filtering kernel; determining at least one element participating in the filtering process within each filtering kernel based on the numerical values ​​of the corresponding positions of the multiple elements in the filtering mask matrix; and using the at least one element participating in the filtering within each filtering kernel to perform filtering processing within each filtering kernel to obtain the filtered response information of the full-field phase information.

[0011] In one embodiment of the first aspect of this application, transforming the filter response matrix from the intensity space to the phase space to obtain the filtering result of the full-field phase information includes: performing arctangent processing on the filter response information to obtain the filtering result of the full-field phase information.

[0012] In one embodiment of the first aspect of this application, the step of using at least one element participating in filtering within each filtering kernel to perform filtering processing within each filtering kernel includes:

[0013] Through formula The filter response elements within each of the filter kernels are obtained, and the filter response matrix is ​​obtained based on all the filter response elements; wherein the size of the filter kernel is (z, z), I c (x+i, y+j) and I s (x+i, y+j) represents the value of the element (x+i, y+j) in the light intensity spatial information of the full-field phase information, and M(x+i, y+j) represents the value of the element (x+i, y+j) in the filter mask matrix.

[0014] In one embodiment of the first aspect of this application, the step of using at least one element participating in filtering within each filter kernel to perform filtering processing in each filter kernel to obtain the filtering response information of the full-field phase information includes: using a sliding window method, taking each element in the full-field phase information as the center of the filter kernel, and sequentially using at least one element participating in filtering within each filter kernel to perform filtering processing in each filter kernel to obtain the filtering response information of the full-field phase information; or, taking each element in the full-field phase information as the center of the filter kernel, and simultaneously using at least one element participating in filtering within each filter kernel to perform filtering processing in each filter kernel to obtain the filtering response information of the full-field phase information.

[0015] In one embodiment of the first aspect of this application, the filtering process includes: mean filtering.

[0016] A second aspect of this application provides a three-dimensional measurement system, comprising: an electronic device, a transmitting device, and a acquiring device, wherein the transmitting device and the acquiring device are respectively connected to the electronic device; wherein the electronic device is configured to perform a three-dimensional measurement method as provided in any of the first aspects of this application, for example, controlling the transmitting device to sequentially project multiple projection images onto the surface of an object to be detected, controlling the acquiring device to acquire multiple reflection images obtained after the surface of the object to be detected reflects light from the multiple projection images; determining full-field phase information and light intensity modulation information corresponding to the multiple reflection images based on the sinusoidal fringes of the multiple reflection images; determining filtering parameters based on the light intensity modulation information; filtering the full-field phase information using the filtering parameters; and determining the three-dimensional information of the surface of the object to be detected based on the filtered full-field phase information.

[0017] In summary, the three-dimensional measurement method and system provided in this application, after the electronic device obtains multiple reflection images of the object's surface, not only determines the full-field phase information based on the multiple reflection images, but also determines the light intensity modulation information based on the multiple reflection images. Furthermore, it filters the full-field phase information using filtering parameters determined by the light intensity modulation information, and finally uses the filtered full-field phase information to determine the three-dimensional information of the object's surface. Therefore, by filtering the full-field phase information, this application reduces noise in the full-field phase information, avoids noise contained in the full-field phase information due to external interference factors, and improves the measurement accuracy and stability during three-dimensional measurement. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram illustrating one application scenario of this application;

[0020] Figure 2 A schematic diagram of the processing performed on the launching device;

[0021] Figure 3 A schematic diagram of the processing performed by the data acquisition device;

[0022] Figure 4 This is a flowchart illustrating an embodiment of the three-dimensional measurement method provided in this application;

[0023] Figure 5 This is a schematic diagram illustrating the processing of a reflected image provided in this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “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.

[0026] Before formally introducing the embodiments of this application, the application scenario will be described in conjunction with the accompanying drawings. Specifically, this application is applied in 3D Automatic Optic Inspection (3D AOI) technology. 3D AOI technology measures the three-dimensional coordinates and surface features of an object's surface non-contactly through optical projection. For example, it can be applied to high-speed, high-precision quantitative defect detection of the surface of products produced on a production line. 3D automatic optical inspection can also be referred to as three-dimensional surface imaging technology, three-dimensional topography scanning, topography measurement, distance imaging, and depth imaging, etc.

[0027] For example, Figure 1 This is a schematic diagram of one application scenario of this application, in which... Figure 1In the illustrated scenario, a three-dimensional measurement system comprised of an electronic device 40, a transmitting device 20, and a data acquisition device 30 is used to measure the three-dimensional information of the surface of the object 10 to be inspected. The transmitting device 20 and the data acquisition device 30 can be controlled by the same electronic device 40, or they can be controlled by separately connected electronic devices. To measure the three-dimensional information of the surface of the object 10, the electronic device 40 first projects a sinusoidal phase-shifted fringe projection image onto the surface of the object 10 through the transmitting device 20, which can be a projector or similar device. Subsequently, after the light from the projected image on the surface of the object 10 is reflected, the electronic device 40 then collects the reflected light from the surface of the object 10 through the data acquisition device 30, which can be a camera or similar device. Because the unevenness of the surface of object 10 causes light to bend, the sinusoidal fringes in the projected image projected onto the surface of object 10 by the transmitting device 20 undergo a phase shift as they pass through the uneven area of ​​object 10. This results in the acquisition device 30 acquiring a phase value in the reflected image that includes information about the deformation of the surface of the object 10. Therefore, the electronic device 40 can obtain the phase change through the reflected image acquired by the acquisition device 30, and thus determine the three-dimensional information of the object's surface.

[0028] In some technologies, three-dimensional surface imaging techniques based on fringe phase measurement (PMP) are widely used. Figure 1 In the scene shown, the acquired reflection image is detected. Specifically, in order to implement the above-mentioned PMP-based 3D surface imaging technology, Figure 2 This is a schematic diagram of the processing performed by the transmitting device. Before transmitting the projected image, the transmitting device generates multiple sinusoidal phase-shifted fringe projection images of different frequencies using electronic equipment. The multiple projection images at each frequency are phase-modulated, and then the generated projection images are sequentially transmitted to the surface of the object via the transmitting device. For example, in... Figure 2 In step S11 shown, the electronic device generates three projected images of frequency ① and three projected images of frequency ② as an example. In each of the three projected images of frequency ①, the phase is modulated according to a certain step size. That is to say, in each of the three projected images of frequency ②, the three projected images have the same frequency but different phases.

[0029] In some embodiments, the projected image can be represented by the following formula: I n (x,y)=C(x,y){A(x,y)+B(x,y)cos[φ(x,y)+2πn / K]} Formula 1

[0030] Where x∈[1,M], y∈[1,N], M and N represent the number of columns and rows of pixels in the projected image, respectively. n (x, y) represents the light intensity at pixel position (x, y) in the nth projected image, i.e., the image coding intensity, n = 0, 1, ..., K, A(x, y) is the background light intensity, or light intensity bias value, B(x, y) is the light intensity modulation amplitude, or sine amplitude value, B(x, y) / A(x, y) is the contrast of the striped grating in the projected image, and K is the phase shift step of the grating stripes in the projected image.

[0031] Subsequently, when the electronic device will Figure 2 Multiple projection images of various frequencies generated in the process are sequentially projected onto the surface of an object through a transmitting device in the form of visible light. The electronic device then collects the reflection image of each image on the object surface through a collection device. The number of reflection images is the same as the number of projection images. Subsequently, the electronic device uses the acquired images to calculate the phase information corresponding to the stripes in the reflection image from Formula 1.

[0032] For example, Figure 3 A schematic diagram of the processing performed by the acquisition device, wherein, Figure 3 In step S21 shown, the electronic device obtains the information from the transmitting device through the acquisition device. Figure 2 The same number of reflected images are emitted from the surface of the object, and it can be seen that the unevenness of the object's surface has an effect. Figure 2 The vertical stripes in the reflected image are reoriented. Then, in S22, the electronic device decodes the reflected image using an arctangent function to obtain a multi-frequency deformable phase map corresponding to each frequency, for example, in... Figure 3 In the example shown, a multi-frequency deformable phase map can be obtained from the three reflection images of frequency ①, and another multi-frequency deformable phase map can be obtained from the three reflection images of frequency ②. Then, in S23, the electronic device performs heterodyne processing on the multiple deformable phase maps from S22 to obtain φ(x, y), which is the phase distribution modulated by the object's height, also known as the equivalent phase or wrapping phase. For example, the equivalent phase φ(x, y) in the reflection image obtained by the k-step phase shift method is shown in Formula 2:

[0033]

[0034] And the intensity modulation amplitude B(x, y) is obtained through Formula 3:

[0035]

[0036] However, in Formula 2 above, since the arctangent function can only obtain the wrapped phase in the range (-π, π) during phase decoding, the resulting equivalent phase φ(x, y) is discontinuous, equivalent to performing a 2π modulo operation on the true phase. This makes the equivalent phase φ(x, y) non-unique, leading to phase ambiguity. Therefore, it is necessary to perform phase expansion on the equivalent phase φ(x, y) obtained in S23 to make it continuous. This process can also be called phase unwrapping. By using the correspondence between the deformed phase in S23 and the original phase in S11, after obtaining the wrapped phase in S23, the true full-field phase in S24 can be recovered. The correspondence between the wrapped phase in S23 and the full-field phase in S24 can be expressed by the following Formula 4:

[0037]

[0038] Where w(x, y) is the phase series or fringe order, etc., which is calculated by the ablation algorithm based on multi-frequency, multi-wavelength, and number theory. For example, using the dual-frequency ablation algorithm, w(x, y) can be calculated by the following formula:

[0039]

[0040] Where, λ l ,λ h φ represents the period of the high-frequency and low-frequency fringes, respectively. l ,φ h This indicates the principal phase value corresponding to the high and low frequency stripes.

[0041] Therefore, by unwrapping the equivalent phase φ(x,y) using Formulas 5 and 4 above, the full-field phase can be obtained by combining the equivalent phase φ(x,y).

[0042] In summary, through the above... Figures 2-3 In the PMP-based three-dimensional optical measurement method shown, although the electronic device can determine the phase value of the image after reflection from the object by transmitting and receiving sinusoidal fringe images, and thus determine the three-dimensional information, the full-field phase calculated in the above process is affected by various interference factors such as ambient light, vibration, and thermal noise during the operation of the transmitting and acquiring devices. It contains a lot of noise, that is, there is incorrect phase information. If the full-field phase is used directly... Determining the three-dimensional information of an object's surface can lead to errors in measurement results, thereby reducing the accuracy and stability of three-dimensional optical measurements.

[0043] Therefore, this application provides a three-dimensional measurement method and system. After the electronic device obtains multiple reflection images of an object's surface, in addition to determining the full-field phase information from the multiple reflection images, it also determines the light intensity modulation information based on the multiple reflection images. Furthermore, it filters the full-field phase information using filtering parameters determined by the light intensity modulation information, and finally uses the filtered full-field phase information to determine the three-dimensional information of the object's surface. The technical solution of this application will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0044] Figure 4 This is a flowchart illustrating an embodiment of the three-dimensional measurement method provided in this application, as shown below. Figure 1 The method shown can be applied to, for example Figure 1 The 3D measurement system in the scene shown consists of an electronic device 40, a transmitting device 20, and a data acquisition device 30, which together measure the 3D information of the object 10 to be detected. Specifically, as shown... Figure 4 The three-dimensional measurement methods shown include:

[0045] S101: Electronic device 40 determines multiple projected images to be projected.

[0046] S102: Electronic device 40, through transmitting device 20, projects multiple projection images determined in S101 onto the surface of object 10 to be detected by visible light in sequence.

[0047] In this embodiment, S101-S102 can be configured as follows: Figure 4 The specific method of projecting the projected image in the projection part of P1 can refer to the prior art, and the embodiments of this application do not limit it.

[0048] S103: Electronic device 40, through acquisition device 30, sequentially acquires multiple reflected images obtained after the object to be detected reflects the light from multiple projected images emitted by the transmitting device 20 in S102.

[0049] S103 can be configured as follows: Figure 4 The acquisition part of P2 in the process is executed in accordance with the steps S102-S103. For example, after the electronic device determines multiple projection images in S101, it sends the first projection image to the object to be detected through S102, and then acquires the first reflection image corresponding to the first projection image through S103. Then, it sends the second projection image to the object to be detected through S102, and continues to acquire the second reflection image corresponding to the second projection image through S103, and so on, until multiple reflection images are finally obtained.

[0050] Subsequently, after the P1 projection and P2 acquisition processes, the electronic device 40 acquires multiple reflection images, which can then be processed as follows: Figure 4 The filtering section of P3 filters the full-field phase information obtained from multiple reflection images, and then... Figure 4 The P4 detection section measures the three-dimensional information of the object's surface based on the filtered full-field phase information. For example... Figure 4 The filtering section of P3 shown specifically includes:

[0051] S104: Determine the full-field phase information corresponding to the multiple reflection images based on the sinusoidal fringes of the multiple reflection images acquired in S103.

[0052] After obtaining multiple reflection images, the electronic device can determine the equivalent phase information φ(x, y) in the reflection images using methods such as multi-step phase shifting, according to Formula 2. Then, by using methods such as multi-frequency extension, the equivalent phase is unwrapped according to Formula 4 to obtain the full-field phase information. Figure 5 This application provides a schematic diagram of processing a reflected image, wherein the process of processing the reflected image is illustrated through a visual image example, such as... Figure 5 The multiple reflection images acquired in S31 shown can be processed by a multi-step phase shifting method to obtain the full-field phase information in S32. After the equivalent phase information is unwrapped, the full-field phase information in S33 can be obtained.

[0053] It should be noted that the methods for determining equivalent phase information and unpacking to obtain full-field phase information provided in the embodiments of this application are merely examples, and other methods can also be used to obtain this information.

[0054] S105: Based on the sinusoidal fringes of the multiple reflection images acquired in S103, determine the light intensity modulation information corresponding to the multiple reflection images.

[0055] After obtaining multiple reflected images, the electronic device can calculate the light intensity modulation amplitude information B(x, y) using a method similar to Formula 3. Figure 5 Taking the example shown, the light intensity modulation information in S34 can be obtained based on the equivalent full-field phase information in S32. In this embodiment, the order of S104 and S105 is not limited, and they can be executed simultaneously.

[0056] S106: The electronic device performs filtering processing on the full-field phase information determined in S104 based on the filtering parameters determined by the light intensity modulation information determined in S105.

[0057] Specifically, since the light intensity modulation parameters in this embodiment are urgently needed to filter the full-field phase information, when the full-field phase information is obtained through S105... Then, in S106, the full-field phase information can first be transformed into the intensity space using the following formula six:

[0058]

[0059]

[0060] Subsequently, a filter mask matrix M(x, y) determined based on the relationship between the value of each element in the light intensity modulation information B(x, y) and a preset threshold is used as the filtering parameter. The filter mask matrix M(x, y) and the light intensity modulation information B(x, y) have the same matrix size and contain the same element distribution. Each element in the filter mask matrix indicates whether to mask the elements of the light intensity modulation information B(x, y) in the light intensity spatial information.

[0061] In some embodiments, when generating the filter mask matrix based on the light intensity modulation information, a preset threshold t can be set. The positions of elements in the light intensity modulation information B(x, y) whose values ​​are greater than or equal to the preset threshold t are taken as the positions of elements 1 in the filter mask matrix M(x, y); and the positions of elements in the light intensity modulation information B(x, y) whose values ​​are less than the preset threshold t are taken as the positions of elements 0 in the filter mask matrix M(x, y). The above process can be represented by the following formula:

[0062]

[0063] The preset threshold t can be manually set or a decimal between 0 and 1 obtained through an adaptive algorithm based on historical results of light intensity modulation information. When the value of an element in the light intensity modulation information B(x, y) is greater than or equal to the preset threshold t, it indicates that the value of the element is relatively accurate and an accurate filtering result can be obtained in the subsequent filtering process. Therefore, the value at the corresponding position of the element in the filter mask matrix is ​​set to 1, and no masking processing is performed on the element thereafter. When the value of an element is less than the preset threshold t, it indicates that the value of the element is inaccurate and may affect the subsequent filtering result. Therefore, the value at the corresponding position of the element in the filter mask matrix is ​​set to 0, and masking processing is performed on the element thereafter.

[0064] Subsequently, the determined filter mask matrix M(x, y) is used to filter the phase information across the entire field. Spatial information of light intensity I s (x, y) and I cThe filter response information f(x, y) is obtained by filtering the phase information of the entire field in the intensity space. Specifically, the above filtering process can be to perform mean filtering on the intensity space information Is(x, y) and Ic(x, y) of the entire field phase information in the intensity space.

[0065] In some embodiments, the above-mentioned mean filtering process specifically includes setting a filter kernel of a preset size (z, z), using each element (x, y) as the center of the filter kernel, and determining at least one element within the filter kernel that participates in the filtering process in conjunction with the filter mask matrix M(x, y). Specifically, elements within the filter kernel corresponding to a value of 0 in the filter mask matrix M(x, y) do not participate in the filtering process, while elements within the filter kernel corresponding to a value of 1 in the filter mask matrix M(x, y) participate in the filtering process. Subsequently, using the following formula (Equation 8), the at least one element within the filter kernel participating in the filtering process is distributed within each filter kernel for filtering.

[0066]

[0067] Where int() is the integer rounding operation, I c (x+i, y+j) and I s (x+i, y+j) represents the value of the element (x+i, y+j) in the intensity spatial information of the full-field phase information, and M(x+i, y+j) represents the value of the element (x+i, y+j) in the filter mask matrix. Therefore, using the above formula eight, each element (x, y) in the full-field phase information is sequentially used as the center of the filter kernel, resulting in the filter response element f(x, y) of the filter kernel centered on that element. The filter response elements f(x, y) of all element-centered filter kernels constitute the filter response information T1(x, y). The size and distribution of the filter response information matrix are the same as those of the full-field phase information matrix.

[0068] In some embodiments, the electronic device can use a sliding window method, taking each element of the full-field phase information as the center of a filter kernel, and sequentially obtaining the filter response element f(x, y) of the filter kernel centered on each element using Equation 8. Alternatively, due to the independence of the calculation of each filter kernel, the electronic device can also use parallel processing, taking each element of the full-field phase information as the center of a filter kernel, and using at least one element participating in filtering within each filter kernel to perform filtering processing simultaneously within each filter kernel, thereby simultaneously calculating the filter response information of the full-field phase information.

[0069] Finally, the obtained filtered response information T1(x, y) is processed by arctangent using the following formula (Equation 9) to transform the filtered response information T1(x, y) from the intensity space to the phase space, thus obtaining the filtered result of the full-field phase information.

[0070]

[0071] S107: Using the filtered full-field phase information from S106, determine the three-dimensional information of the surface of the object to be detected.

[0072] In some embodiments, the electronic device can specifically determine the three-dimensional information of the surface of the object to be detected, such as its height, based on the numerical value of the full-field phase information through phase-height mapping. This application emphasizes the method of filtering the full-field phase information, but does not limit the method of obtaining the three-dimensional information of the surface of the object to be detected from the filtered full-field phase information.

[0073] by Figure 5 Taking the example shown, the full-field phase information in S33 can be filtered according to the filtering parameters in S34 to obtain the filtered and de-denoised full-field phase information in S35. Subsequently, the depth data representing the three-dimensional information of the object surface in S36 is obtained through phase-height mapping.

[0074] In summary, the three-dimensional measurement method provided in this application involves an electronic device obtaining multiple reflection images of an object's surface. In addition to determining the full-field phase information through these multiple reflection images, it also determines the light intensity modulation information based on the multiple reflection images. Furthermore, it filters the full-field phase information using the filtering parameters determined by the light intensity modulation information, and finally uses the filtered full-field phase information to determine the three-dimensional information of the object's surface.

[0075] Therefore, this embodiment of the application reduces noise in the full-field phase information by filtering the full-field phase information, avoids noise contained in the full-field phase information due to external interference factors, and improves the measurement accuracy and stability when performing three-dimensional measurements.

[0076] Furthermore, in the embodiments of this application, the filtering parameters obtained through the light intensity modulation information can determine at least one element in the filtering kernel that participates in the filtering operation during filtering, and perform masking processing on other elements. Therefore, it can filter out spike noise in the full-field phase information and has good robustness against spike noise.

[0077] Furthermore, the three-dimensional measurement method provided in this application can be applied to the field of industrial measurement. By processing all filter kernels in the full-field phase information in parallel, it can filter the full-field phase information without increasing the filtering time excessively, thus simultaneously meeting the requirements of accuracy and speed in three-dimensional measurement and improving the efficiency of three-dimensional measurement.

[0078] It should be noted that the division of various devices / devices in the three-dimensional measurement system described above in this embodiment is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. For example, the transmitting device and the acquisition device can be integrated into an electronic device. These modules can be implemented entirely in software through processing elements; they can also be fully implemented in hardware; or some modules can be implemented by processing elements calling software, while others are implemented in hardware. A processing element can be a separate entity, or it can be integrated into a chip within the aforementioned device. Alternatively, it can be stored as program code in the memory of the aforementioned device, and called and executed by a processing element of the aforementioned device. The implementation of other modules is similar. Furthermore, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element described here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed through integrated logic circuits in the hardware of the processor element or through software instructions.

[0079] For example, these modules / units can be one or more integrated circuits configured to implement the above methods, such as one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs). As another example, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together to implement a system-on-a-chip (SOC).

[0080] In the above embodiments, the method steps executed by the electronic device in the three-dimensional measurement system, whether all or part of them, can be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks (SSDs)).

[0081] This application also provides an electronic device, including: a processor and a memory; wherein, the memory stores a computer program, and when the processor executes the computer program, the processor can be used to perform any of the three-dimensional measurement methods as described in the foregoing embodiments of this application.

[0082] This application also provides a computer-readable storage medium storing a computer program, which, when executed, can be used to perform any of the three-dimensional measurement methods described in the foregoing embodiments of this application.

[0083] This application also provides a chip for executing instructions, the chip being used to perform a three-dimensional measurement method executed by an electronic device as described in any of the foregoing embodiments of this application.

[0084] This application also provides a program product, which includes a computer program stored in a storage medium. At least one processor can read the computer program from the storage medium. When the at least one processor executes the computer program, it can implement the three-dimensional measurement method performed by an electronic device as in any of the foregoing embodiments of this application.

[0085] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A three-dimensional measurement method characterized by, The method comprises the following steps: projecting a plurality of projection images on the surface of the object to be detected in sequence by visible light, wherein each of the projection images comprises a plurality of sinusoidal fringes; collecting a plurality of reflection images obtained by reflecting the plurality of projection images on the surface of the object to be detected; determining full-field phase information and light intensity modulation information corresponding to the plurality of reflection images according to the sinusoidal fringes of the plurality of reflection images; transforming the full-field phase information from a phase space to a light intensity space to obtain light intensity space information of the full-field phase information; determining a filtering parameter according to the light intensity modulation information, wherein the filtering parameter comprises a filtering mask matrix, and elements in the filtering mask matrix are used to indicate whether corresponding elements in the light intensity space information are subjected to mask processing; performing filtering processing on the light intensity space information by using the filtering parameter to obtain filtering response information of the full-field phase information in the light intensity space; transforming the filtering response information from the light intensity space to the phase space to obtain a filtering result of the full-field phase information. determining three-dimensional information of the surface of the object to be detected according to the filtered full-field phase information.

2. The method of claim 1, wherein, The method further comprises the following steps: determining the filtering parameter according to a relationship between a value of each element in the light intensity modulation information and a preset threshold.

3. The method of claim 2, wherein, The method further comprises the following steps: taking a position of an element with a value greater than or equal to the preset threshold in the light intensity modulation information as a position of element 1 in the filtering mask matrix; taking a position of an element with a value less than the preset threshold in the light intensity modulation information as a position of element 0 in the filtering mask matrix.

4. The method of claim 3, wherein, The method further comprises the following steps: taking each element in the full-field phase information as a center of a filtering kernel to obtain a plurality of elements in the full-field phase information in a preset size corresponding to each filtering kernel; determining at least one element in each filtering kernel participating in filtering processing according to values of positions of the plurality of elements in the filtering mask matrix; performing filtering processing in each filtering kernel by using the at least one element participating in filtering in each filtering kernel to obtain the filtering response information of the full-field phase information.

5. The method of claim 4, wherein, The method further comprises the following steps: performing arctangent processing on the filtering response information to obtain the filtering result of the full-field phase information.

6. The method of claim 5, wherein, The method further comprises the following steps: The filter response information is obtained by formula The filter response information is obtained by formula wherein the size of the filter kernel is (z, z), I c (x+i, y+j) and I s (x+i, y+j) is the value of the (x+i, y+j) element in the spatial intensity information of the full-field phase information, M(x+i, y+j) is the value of the (x+i, y+j) element in the filter mask matrix, int() is the rounding operation , , is the full-field phase information.

7. The method of claim 6, wherein, performing filtering processing in each filtering kernel by using the at least one element participating in filtering in each filtering kernel to obtain the filtering response information of the full-field phase information. The method further comprises the following steps: By using the sliding window method, each element in the full-field phase information is taken as the center of the filter kernel, and at least one element in each filter kernel is used to perform filtering processing in each filter kernel in turn to obtain the filtering response information of the full-field phase information. Alternatively, each element in the full-field phase information can be used as the center of a filter kernel, and at least one element participating in the filtering within each filter kernel can be used simultaneously for filtering to obtain the filtered response information of the full-field phase information.

8. The method according to any one of claims 1-7, characterized in that, The filtering process includes: mean filtering.

9. A three-dimensional measurement system, characterized by include: An electronic device, a transmitting device, and a data acquisition device, wherein the transmitting device and the data acquisition device are respectively connected to the electronic device; The electronic device is used to control the transmitting device to sequentially project multiple projection images onto the surface of the object to be detected, wherein each projection image includes multiple sinusoidal fringes; The electronic device is also used to control the acquisition device to acquire multiple reflected images obtained after the surface of the object to be detected reflects light from the multiple projected images; The electronic device is further configured to: determine the full-field phase information and light intensity modulation information corresponding to the plurality of reflected images based on the sinusoidal fringes of the plurality of reflected images; transform the full-field phase information from phase space to light intensity space to obtain the light intensity space information of the full-field phase information; determine filtering parameters based on the light intensity modulation information; the filtering parameters include: a filtering mask matrix, the elements of the filtering mask matrix being used to indicate whether to perform masking processing on the corresponding elements in the light intensity space information; perform filtering processing on the light intensity space information using the filtering parameters to obtain the filtering response information of the full-field phase information in the light intensity space; transform the filtering response information from light intensity space to phase space to obtain the filtering result of the full-field phase information; and determine the three-dimensional information of the surface of the object to be detected based on the filtered full-field phase information.

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