Phase decoding method and device for dynamic object three-dimensional structured light imaging

Abstract

The application discloses a kind of phase decoding method and device for dynamic object three-dimensional structured light imaging, and the method steps include: capturing the image of two groups of modulation stripes projected on the measured object, two groups of modulation stripes are projected on the measured object after being generated in advance according to different frequencies, each group of modulation stripes includes multiple longitudinal stripes and a horizontal stripe, or includes multiple horizontal stripes and a longitudinal stripe;According to the captured modulation stripe image, solve longitudinal wrapped phase using n' step phase shift method, and calculate average light intensity and modulation light intensity, to solve horizontal wrapped phase, finally, difference method is used to unwrap longitudinal wrapped phase and horizontal wrapped phase to obtain longitudinal absolute phase and horizontal absolute phase.The application has the advantages of simple implementation method, low cost, high decoding efficiency and high precision.

Description

Technical Field

[0001] This invention relates to the field of spatial measurement technology for dynamic objects, and in particular to a phase decoding method and apparatus for three-dimensional structured light imaging of dynamic objects. Background Technology

[0002] Traditional methods for measuring static objects in 3D suffer from poor flexibility, significantly reducing production efficiency and failing to meet the current demands for measuring dynamic objects. Structured light 3D imaging technology utilizes auxiliary structured light illumination to acquire a 3D image of an object. This involves projecting a carrier frequency fringe onto the surface of the object, recording the deformed fringe image—modulated by the object's height—from another angle using an imaging device, and then reconstructing a 3D digital image of the object through phase decoding. The accuracy and efficiency of phase decoding directly determine the quality of the reconstructed 3D digital image.

[0003] Existing technologies for structured light 3D imaging of objects typically rely on multi-frequency, multi-step phase-shifting methods. However, these methods require a large number of projected fringes to ensure measurement accuracy. For example, it is usually necessary to measure fringe images with different projected frequencies (frequency number greater than or equal to 2) and different phase-shifting steps (phase-shifting steps greater than or equal to 3) in both directions (horizontal x and vertical y), requiring at least 2 × 3 × 2 = 12 fringe images. Then, the imaging device sequentially records the highly modulated deformed fringe images of the imaged object. Therefore, a large number of fringe images need to be processed, resulting in low measurement efficiency. Although the above methods are well-suited for static objects, they require extensive image processing calculations when applied to the measurement of dynamic objects, making them unsuitable for measuring dynamic objects, especially for the accurate and efficient measurement of a large number of dynamic objects.

[0004] Some practitioners have proposed improving measurement efficiency by changing the encoding method (RGB stripe encoding technology) and reducing stripe images when measuring dynamic objects using structured light 3D imaging technology. While such methods can improve measurement efficiency to some extent, they actually sacrifice imaging accuracy, resulting in low final imaging precision. Other methods, such as upgrading hardware (e.g., using high-frame-rate high-speed cameras to reduce recording time), would significantly increase implementation costs and are not suitable for acquiring large-scale stripe images. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a phase decoding method and apparatus for three-dimensional structured light imaging of dynamic objects that is simple to implement, low in cost, efficient in decoding, and highly accurate, in response to the technical problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] A phase decoding method for three-dimensional structured light imaging of dynamic objects, comprising the following steps:

[0008] Capture images of two sets of modulation stripes projected onto the object under test. The two sets of modulation stripes are generated in advance at different frequencies and then projected onto the object under test. Each set of modulation stripes includes multiple longitudinal stripes and one transverse stripe, or multiple transverse stripes and one longitudinal stripe.

[0009] The longitudinal wrapping phase is solved using the n′-step phase-shifting method based on the captured modulated stripe image, where n′≥3;

[0010] The average light intensity and the modulated light intensity are calculated based on the captured modulated stripe image, and the lateral wrapping phase is calculated based on the average light intensity and the modulated light intensity.

[0011] The longitudinal and transverse wrapping phases are expanded using the frequency difference method to obtain the longitudinal absolute phase and the transverse absolute phase.

[0012] Furthermore, the expression for the longitudinal stripes is:

[0013]

[0014] The expression for the horizontal stripes is:

[0015] Ih(x p ,y p ) = A p (x p ,y p )+B p (x p ,y p cos(2πf) j y p )

[0016] in, Vertical stripes, Ih p Horizontal stripes, f i For the i-th frequency, A p (x p ,y p B represents the amplitude value of the DC component signal. p (x p ,y p (x) represents the amplitude value of the AC component signal. p ,y p ) represents the pixel coordinates of the projector, n represents the phase shift index number, and N represents the total number of phase shift steps.

[0017] Furthermore, in the captured image of two sets of modulated stripes projected onto the object under test, each set of modulated stripes consists of n′ longitudinal stripes and one transverse stripe, or n′ transverse stripes and one longitudinal stripe.

[0018] Furthermore, when using the three-step phase-shift method to solve for the longitudinal wrapping phase, the calculation expression for the longitudinal wrapping phase is:

[0019]

[0020] Wherein, I0, I1, and I2 are the light intensities of the fringe patterns in steps 1, 2, and 3, respectively.

[0021] When the longitudinal wrapping phase is solved using three or more steps, the calculation expression for the longitudinal wrapping phase is:

[0022]

[0023] Where n is the phase shift index number, N is the phase shift step number, and I n The intensity of the fringe pattern at step n-1 is given.

[0024] Furthermore, when the longitudinal wrapping phase is obtained using the three-step phase-shifting method, the expressions for calculating the average light intensity and the modulated light intensity are as follows:

[0025]

[0026]

[0027] When solving the longitudinal wrapping phase using three or more steps, the expressions for calculating the average light intensity and the modulated light intensity are as follows:

[0028]

[0029]

[0030] Where A is the average light intensity, B is the modulated light intensity, n is the phase shift index number, and N is the phase shift step number.

[0031] Furthermore, based on the longitudinal and lateral wrapping phases, the dual-frequency heterodyne method is used to calculate the longitudinal absolute phase and lateral absolute phase, and the calculation expressions are as follows:

[0032]

[0033] or

[0034]

[0035] Φ1=2πm+φ1

[0036] Where, round() is the nearest integer, and m is the number of stripe periods to which the current point belongs;

[0037] φ 12 The phase difference between the two frequencies used to generate the modulation stripes is calculated as follows:

[0038]

[0039] Where Φ1 and Φ2 are the absolute phases corresponding to the two frequencies, and φ1 and φ2 are the two frequencies.

[0040] Furthermore, after calculating the longitudinal absolute phase and the transverse absolute phase according to the longitudinal wrapping phase and transverse wrapping phase frequency difference method, the method further includes obtaining the absolute phase values ​​calculated at different frequencies and fusing them to obtain the final absolute phase value.

[0041] Furthermore, the absolute phases calculated at different frequencies are weighted and fused to obtain the final absolute phase value, and the calculation expression is as follows:

[0042] Φ = w1Φ1 + w2Φ2 + ... + w n Φ n

[0043] Where Φ is the final absolute phase value, Φ1~Φ n The absolute phase values ​​calculated for each frequency are w1 to w2, respectively. n These are the weighting coefficients, and n is the number of frequencies.

[0044] A phase decoding device for three-dimensional structured light imaging of dynamic objects, comprising:

[0045] The capture module is used to capture images of two sets of modulation stripes projected onto the object under test. The two sets of modulation stripes are generated in advance according to different frequencies and then projected onto the object under test. Each set of modulation stripes includes multiple vertical stripes and one horizontal stripe, or multiple horizontal stripes and one vertical stripe.

[0046] The longitudinal wrapping phase solution module is used to solve the longitudinal wrapping phase using the n′-step phase shift method based on the captured modulation stripe image, where n′≥3;

[0047] The lateral wrapping phase solving module is used to calculate the average light intensity and the modulated light intensity based on the captured modulated stripe image, and to calculate the lateral wrapping phase based on the average light intensity and the modulated light intensity.

[0048] The absolute phase calculation module is used to calculate the longitudinal absolute phase and the transverse absolute phase based on the longitudinal wrapping phase and the transverse wrapping phase using the frequency difference method, thereby completing phase decoding.

[0049] A computer device includes a processor and a memory, the memory being used to store a computer program, and the processor being used to execute the computer program to perform the method described above.

[0050] Compared with the prior art, the advantages of the present invention are as follows:

[0051] 1. This invention addresses phase decoding for 3D structured light imaging of dynamic objects. It employs different methods to solve for the longitudinal and lateral wrapping phases. The longitudinal wrapping phase is solved using an n′-step phase shift method, while the lateral wrapping phase is calculated by first determining the average light intensity and modulated light intensity, and then using a single-step frequency difference method based on these indices to finally calculate the longitudinal and lateral absolute phases. This forms an n′+1-step phase decoding method. By calculating the variable values ​​of the lateral fringes to reduce the number of longitudinally projected fringes, or vice versa, the number of fringes required for projection can be effectively reduced. This significantly improves the efficiency of phase decoding while ensuring accuracy, achieving highly efficient phase decoding for 3D structured light imaging of dynamic objects.

[0052] 2. This invention further utilizes the characteristics of higher high-frequency phase accuracy and more stable low-frequency phase by performing multi-frequency fusion on the absolute phase obtained at different frequencies. This effectively evaluates the phase quality and solves the problems of poor high-frequency stability and poor low-frequency accuracy in traditional single-frequency phase measurement methods, thereby further improving the phase decoding accuracy and the quality of the generated absolute phase image. Attached Figure Description

[0053] Figure 1 This is a schematic diagram illustrating the implementation process of the phase decoding method for dynamic object three-dimensional structured light imaging in this embodiment.

[0054] Figure 2 This is a schematic diagram of the system structure for phase decoding of dynamic object three-dimensional structured light imaging in this embodiment.

[0055] Figure 3 This is a schematic diagram of the phase decoding process for realizing three-dimensional structured light imaging of dynamic objects in a specific application embodiment of the present invention. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0057] like Figure 1 As shown, the steps of the phase decoding method for dynamic object three-dimensional structured light imaging in this embodiment include:

[0058] S01. Capture images of two sets of modulation stripes projected onto the object under test. The two sets of modulation stripes are generated in advance according to different frequencies and then projected onto the object under test. Each set of modulation stripes includes multiple longitudinal stripes and one transverse stripe, or multiple transverse stripes and one longitudinal stripe.

[0059] S02. The longitudinal wrapping phase is solved using the n′-step phase-shifting method based on the captured modulated stripe image, where n′≥3;

[0060] S03. Calculate the average light intensity and modulated light intensity based on the captured modulated stripe image, and calculate the lateral wrapping phase based on the average light intensity and modulated light intensity;

[0061] S04. The longitudinal and transverse wrapped phases are expanded using the frequency difference method to obtain the longitudinal absolute phase and transverse absolute phase, thus completing the phase decoding.

[0062] This embodiment addresses phase decoding for 3D structured light imaging of dynamic objects. It employs different methods to solve for the longitudinal and lateral wrapping phases. The longitudinal wrapping phase is solved using an n′-step phase shift method, while the lateral wrapping phase is calculated by first determining the average and modulated light intensities, and then using these intensities to reduce the number of longitudinally projected fringes, or vice versa. Finally, a single-step frequency difference method is used to calculate the absolute longitudinal and lateral phases, forming an n′+1-step phase decoding method. This effectively reduces the number of fringes required for projection, significantly improving efficiency while maintaining accuracy, thus achieving highly efficient phase decoding for 3D structured light imaging of dynamic objects. For example, when using a three-step phase shift method combined with a dual-frequency heterodyne method, only eight fringe images at two frequencies are needed to solve for the bidirectional absolute phase. Compared to traditional bidirectional multi-frequency multi-step phase shift measurements, which require projecting and capturing at least 12 fringe images per measurement, this method improves efficiency by at least one-third.

[0063] In specific application embodiments, such as Figure 2As shown, the three-dimensional measurement system constructed in this embodiment specifically includes three parts: ① projection, ② acquisition, and ③ phase decoding. ① The projection stage includes a projection device to project coded stripes (modulated stripes) generated by a computer; ② The acquisition stage includes a camera that can capture the distorted stripes projected onto the surface of the dynamic object; ③ The phase decoding stage includes a computer that processes the distorted stripes acquired in ② using a phase decoding method to obtain periodic phase information, and then obtains absolute phase information using the phase decoding method described above in this embodiment. Based on this absolute phase information, the dynamic object is imaged, thereby obtaining the spatial position information, motion pattern information, etc., of the dynamic object.

[0064] Before performing phase decoding, modulation stripes are first generated and projected onto the object under test. In specific application embodiments, a computer can be used based on formula (1) at a frequency f i Three vertical stripe images are generated for i=1 and i=2 respectively. Based on formula (2) with frequency f j For j=1 and j=2, generate one horizontal stripe image Ih respectively. p (Horizontal and vertical axes can be interchanged.)

[0065]

[0066] Ih(x p ,y p ) = A p (x p ,y p )+B p (x p ,y p cos(2πf) j y p (2)

[0067] in, Vertical stripes, Ih p Horizontal stripes, f i For the i-th frequency, A p (x p ,y p B represents the amplitude value of the DC component signal. p (x p ,y p (x) represents the amplitude value of the AC component signal. p ,y p ) represents the pixel coordinates of the projector, n represents the phase shift index number, and N represents the total number of phase shift steps, N = 3.

[0068] All the generated fringe images (specifically 8 as mentioned above) are transmitted to the projection device. The projector receives the fringe images and projects them sequentially onto the object under test. The projected fringes are distorted upon reaching the object and, after reflection, are captured by the camera. The image corresponding to a single captured frequency can be represented as:

[0069] Iv n (x,y)=A(x,y)+B(x,y)cos(φ(x,y)-2πn / N), (3)

[0070] Ih(x,y)=A(x,y)+B(x,y)cos(θ(x,y)), (4)

[0071] Where A(x,y) is the average light intensity, B(x,y) is the modulated light intensity, and φ and θ are the longitudinal wrapping phase and the transverse wrapping phase, respectively.

[0072] In step S02 of this embodiment, the longitudinal wrapping phase is solved using n′-step phase shift methods, such as three-step phase shift and four-step phase shift, based on the captured modulation stripe image. The following explanation uses three-step phase shift as an example:

[0073] When using the three-step phase shift method to solve for the longitudinal wrapping phase, the calculation expression for the longitudinal wrapping phase is:

[0074]

[0075] Wherein, I0, I1, and I2 are the light intensities of the fringe patterns in steps 1, 2, and 3, respectively.

[0076] The expressions for calculating the average light intensity and the modulated light intensity are as follows:

[0077]

[0078]

[0079] After obtaining the average light intensity A and the modulated light intensity B, we can enter the formula (4) to obtain the transverse wrapping phase θ. Thus, the solution of the longitudinal wrapping phase φ and the transverse wrapping phase θ is completed. Similarly, the longitudinal wrapping phase and the transverse wrapping phase of other frequencies can be calculated.

[0080] After obtaining the longitudinal wrapping phase φ and the transverse wrapping phase θ at different frequencies, step S04 of this embodiment uses a dual-frequency or multi-frequency heterodyne method to calculate the longitudinal absolute phase Φ and the transverse absolute phase. The solution of the longitudinal absolute phase Φ using the dual-frequency heterodyne method will be explained as an example. 12 The phase difference between the two frequencies used to generate the modulation fringes is calculated using the following expression:

[0081]

[0082] Where Φ1 and Φ2 are the absolute phases corresponding to the two frequencies, and φ1 and φ2 are the two frequencies.

[0083] The absolute phases Φ1 and Φ2 and the periods T1 and T2 of the phase function have the following relationship:

[0084] Φ1T1=Φ2T2 (9)

[0085] By combining equations (8) and (9), the absolute phase corresponding to the principal phase value φ1 can be calculated:

[0086]

[0087] or

[0088]

[0089] Φ1=2πm+φ1 (12)

[0090] Where round() is the nearest integer and m is the number of stripe periods to which the current point belongs.

[0091] When solving for the longitudinal absolute phase Φ using the dual-frequency heterodyne method, the absolute phase Φ1 corresponding to the principal phase value can be calculated according to (10) or according to equations (11) and (12).

[0092] Besides solving the wrapping phase using the 3+1 (3 represents the three-step phase shift method) step phase shift method, other n′-step phase shift methods (n′>3) such as four-step phase shift method can also be used. If other n′-step phase shift methods are used, then in the above formulas (1) and (3), N=n′, n=0,1,...,n′-1, and the specific expression for calculating the longitudinal wrapping phase is as follows:

[0093]

[0094] Where n is the phase shift index number, N is the phase shift step number, and I n The intensity of the fringe pattern at step n-1 is given.

[0095] The specific expressions for calculating the average light intensity and the modulated light intensity are as follows:

[0096]

[0097]

[0098] Where A is the average light intensity, B is the modulated light intensity, n is the phase shift index number, and N is the phase shift step number.

[0099] For the fringes required for projection, if the three-step phase-shifting method is used to solve the longitudinal wrapping phase, each set of fringes can consist of 3 longitudinal fringes + 1 transverse fringe, or 3 transverse fringes + 1 longitudinal fringe. Correspondingly, if the n-step phase-shifting method is used, each set of fringes can consist of n longitudinal fringes + 1 transverse fringe, or n transverse fringes + 1 longitudinal fringe. As can be seen from the above, according to the method of this invention, a minimum of only 8 fringe images are needed to solve the bidirectional absolute phase.

[0100] Furthermore, in this embodiment, after calculating the longitudinal absolute phase and the lateral absolute phase using the longitudinal wrapping phase and lateral wrapping phase frequency difference methods, the method also includes acquiring and fusing absolute phase values ​​calculated at different frequencies to obtain the final phase value. The phase decoding quality is then evaluated based on the final phase value. By performing multi-frequency fusion on the absolute phases obtained at different frequencies, the higher accuracy of high-frequency phases and the more stable characteristics of low-frequency phases can be fully utilized, effectively evaluating the phase quality and solving the problems of poor high-frequency stability and poor low-frequency accuracy in traditional single-frequency phase measurement methods. This further improves the phase decoding accuracy and the quality of the generated absolute phase image.

[0101] In this embodiment, the absolute phase calculated at different frequencies is obtained using a weighted fusion method to arrive at the final phase value. This phase weighting method balances the phase quality at different frequencies.

[0102] Φ = w1Φ1 + w2Φ2 + ... + w n Φ n (16)

[0103] Where w is the weighting coefficient and n is the number of frequencies.

[0104] Understandably, in addition to weighted fusion, other fusion methods can be used for multi-frequency phase fusion according to actual needs.

[0105] like Figure 3 As shown, in a specific application embodiment, when using the above-described method of the present invention to realize phase decoding of dynamic object three-dimensional structured light imaging, firstly, a computer is used at a frequency f i Three vertical stripe images are generated for i=1 and i=2 respectively. n = 0, 1, 2, and with frequency f j For j=1 and j=2, generate one horizontal stripe image Ih respectively. pThe projector projects each stripe onto the object being measured in sequence. The camera captures the modulated stripe image and performs phase decoding. Based on the three-step phase shift method, the longitudinal wrapping phase φ is solved, the average light intensity A and the modulated light intensity B are calculated, and then the transverse wrapping phase θ is obtained. Then, based on the principle of multi-frequency heterodyne method, the longitudinal absolute phase Φ and the transverse absolute phase are calculated. Finally, multi-frequency fusion is performed on the absolute phases obtained at different frequencies to obtain the final absolute phase image.

[0106] This embodiment combines the n′+1 step phase solving method with a multi-frequency fusion strategy, which can improve efficiency while ensuring the accuracy of phase solving, and obtain a high-efficiency and high-precision absolute phase image, thereby efficiently realizing three-dimensional structured light imaging for dynamic objects.

[0107] The phase decoding device for dynamic object three-dimensional structured light imaging in this embodiment includes:

[0108] The capture module is used to capture images of two sets of modulation stripes projected onto the object under test. The two sets of modulation stripes are generated in advance according to different frequencies and then projected onto the object under test. Each set of modulation stripes includes multiple vertical stripes and one horizontal stripe, or multiple horizontal stripes and one vertical stripe.

[0109] The longitudinal wrapping phase solution module is used to solve the longitudinal wrapping phase using the n′-step phase shift method based on the captured modulation stripe image, where n′≥3;

[0110] The lateral wrapping phase solving module is used to calculate the average light intensity and the modulated light intensity based on the captured modulated stripe image, and to calculate the lateral wrapping phase based on the average light intensity and the modulated light intensity.

[0111] The absolute phase calculation module is used to expand the longitudinal and lateral wrapped phases using the frequency difference method to obtain the longitudinal and lateral absolute phases, thus completing the phase decoding.

[0112] In this embodiment, a stripe generation module is also included to generate modulated stripes, and a projection module is included to project the generated modulated stripes onto the object under test. Specifically, the stripe generation module can generate stripes according to equations (1) and (2).

[0113] The phase decoding device for dynamic object three-dimensional structured light imaging in this embodiment corresponds one-to-one with the phase decoding method for dynamic object three-dimensional structured light imaging described above, and will not be described in detail here.

[0114] This embodiment also provides a computer device, including a processor and a memory, wherein the memory is used to store a computer program and the processor is used to execute the computer program to perform the method described above.

[0115] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A phase decoding method for dynamic object three-dimensional structured light imaging, characterized in that, The steps comprise: capturing images of two groups of modulated fringes projected onto the measured object, the two groups of modulated fringes being generated in advance at different frequencies and then projected onto the measured object, each group of modulated fringes comprising a plurality of vertical fringes and one horizontal fringe or a plurality of horizontal fringes and one vertical fringe; According to the captured modulation fringe image employing The longitudinal wrapping phase is solved by step phase shifting method, wherein ; calculating average light intensity and modulated light intensity according to the captured modulated fringe images, and calculating a horizontal wrapped phase according to the average light intensity and the modulated light intensity; calculating a vertical absolute phase and a horizontal absolute phase by unwrapping the vertical wrapped phase and the horizontal wrapped phase using a frequency difference method.

2. The phase decoding method of dynamic object three-dimensional structured light imaging according to claim 1, characterized in that, The expression of the vertical fringe is: The expression of the horizontal fringe is: wherein, is a longitudinal stripe, is a transverse stripe, is a first i is a frequency, is an amplitude value of a direct current component signal, is an amplitude value of an alternating current component signal, is a pixel point coordinate of a projector, is a phase shift index number, is a total phase shift step number.

3. The phase decoding method of dynamic object three-dimensional structured light imaging according to claim 1, characterized in that, Each of the modulation stripes is a longitudinal stripe and one transverse stripe, or a transverse stripe and one longitudinal stripe.

4. The phase decoding method of dynamic object three-dimensional structured light imaging according to claim 1, characterized in that, When the three-step phase shift method is used to solve the vertical wrapped phase, the calculation expression of the vertical wrapped phase is: wherein , and are the light intensities of the 1st, 2nd, 3rd step fringe pattern, respectively. When more than three steps are used to solve the vertical wrapped phase, the calculation expression of the vertical wrapped phase is: wherein is the phase shift index number, is the number of phase shift steps, is the first n -1 step fringe pattern.

5. The phase decoding method of dynamic object three-dimensional structured light imaging according to claim 1, characterized in that, When the three-step phase shift method is used to solve the vertical wrapped phase, the calculation expressions of the average light intensity and the modulated light intensity are respectively: When more than three steps are used to solve the vertical wrapped phase, the calculation expressions of the average light intensity and the modulated light intensity are respectively: wherein is the average light intensity, is the modulated light intensity, , and are the light intensities of the 1st, 2nd, 3rd step fringe pattern, respectively, is the phase shift index number, is the number of phase shift steps.

6. The phase decoding method for dynamic object three-dimensional structured light imaging according to any one of claims 1-5, characterized in that, When the double-frequency heterodyne method is used to calculate the vertical absolute phase and the horizontal absolute phase according to the vertical wrapped phase and the horizontal wrapped phase, the calculation expression is: Or wherein, is the nearest integer, is the number of stripe periods to which the current point belongs; The phase difference between the two frequencies used to generate the modulated fringe, i.e. the calculation expression is: wherein, , are the absolute phases for the two frequencies, respectively, , are the two frequencies, respectively.

7. The phase decoding method for dynamic object three-dimensional structured light imaging according to any one of claims 1-5, characterized in that, After the vertical absolute phase and the horizontal absolute phase are calculated by the frequency difference method according to the vertical wrapped phase and the horizontal wrapped phase, the method further comprises obtaining absolute phase values calculated at different frequencies and fusing the absolute phase values to obtain a final absolute phase value.

8. The phase decoding method of dynamic object three-dimensional structured light imaging according to claim 7, characterized in that, The absolute phase values calculated at different frequencies are fused by a weighted fusion method to obtain the final absolute phase value, and the calculation expression is: wherein, is the final absolute phase value, ~ are absolute phase values calculated for each frequency, ~ are weighting factors, is the number of frequencies.

9. A phase decoding device for dynamic object three-dimensional structured light imaging, characterized in that, The method comprises: a capturing module configured to capture images of two groups of modulated fringes projected onto the measured object, the two groups of modulated fringes being generated in advance at different frequencies and then projected onto the measured object, each group of modulated fringes comprising a plurality of vertical fringes and one horizontal fringe or a plurality of horizontal fringes and one vertical fringe; a longitudinal wrapped phase solving module for solving longitudinal wrapped phase from the captured modulated fringe image using a step phase shifting method, wherein ; a horizontal wrapped phase solving module configured to calculate average light intensity and modulated light intensity according to the captured modulated fringe images, and calculate a horizontal wrapped phase according to the average light intensity and the modulated light intensity; an absolute phase calculating module configured to calculate a vertical absolute phase and a horizontal absolute phase by unwrapping the vertical wrapped phase and the horizontal wrapped phase using a frequency difference method, and complete phase decoding.

10. A computer apparatus comprising a processor and a memory for storing a computer program, characterised in that, The processor is configured to execute the computer program to perform the method of any one of claims 1-8.

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