WO2018119771A1

WO2018119771A1 - Efficient phase-three-dimensional mapping method and system based on fringe projection profilometry

Info

Publication number: WO2018119771A1
Application number: PCT/CN2016/112697
Authority: WO
Inventors: 彭翔; 蔡泽伟; 刘晓利
Original assignee: 深圳大学
Priority date: 2016-12-28
Filing date: 2016-12-28
Publication date: 2018-07-05

Abstract

The present invention is applicable to the technical field of optical three-dimensional digital imaging. Provided is an efficient phase-three-dimensional mapping method based on fringe projection profilometry. The fringe projection profilometry is based on a binocular system, and the binocular system comprises a projection device and an imaging device. The method comprises: step S1, projecting, by using a projection device, a fringe sequence to the surface of an object to be measured, collecting, by an imaging device, a deformed fringe pattern modulated by the surface of the object to be measured, and computing phases of all pixels on an image of the imaging device according to the deformed fringe pattern; and step S2, searching for a phase-three-dimensional mapping coefficient corresponding to each pixel in a preset phase-three-dimensional mapping coefficient lookup table, and plugging the phase of each pixel and the corresponding phase-three-dimensional mapping coefficient into a phase-three-dimensional mapping function, so as to compute three-dimensional coordinates of an object point corresponding to each pixel on the image of the imaging device. By means of the method provided in the present invention, efficient three-dimensional reconstruction of the fringe projection profilometry can be implemented.

Description

Efficient phase-three-dimensional mapping method and system based on stripe projection profilometry

Technical field

The invention belongs to the field of optical three-dimensional digital imaging technology, and in particular relates to an efficient phase-three-dimensional mapping method and system based on stripe projection profilometry.

Background technique

Stripe projection profilometry is a non-contact, full-field optical 3D digital imaging and measurement method; it is based on a binocular system, which typically includes a camera and a projector, where the projector projects a set of sine The stripe sequence is applied to the surface of the object to be measured, and the camera collects the deformed fringe pattern modulated by the surface of the object; the modulation phase of the deformed fringe pattern is obtained by the stripe analysis technique, and the three-dimensional shape of the measured object is recovered from the modulation phase by the scene reconstruction method.

There are two typical three-dimensional reconstruction methods based on fringe projection profilometry: phase-height mapping and stereo vision; among them, phase-height mapping directly maps the phase to height according to the phase and height modulation principle, achieving efficient three-dimensional reconstruction. . However, in practical applications, the phase-height mapping method has some limitations, such as the optical axis of the camera or projector needs to be perpendicular to the reference plane, the line connecting the camera and the projector center is parallel to the reference plane, and the reference plane limits the measurement space and the like. In addition, the phase-height mapping method usually requires the use of a precision displacement platform or gauge block to obtain accurate height values, which is not suitable for field calibration.

The stereo vision method is based on the principle of triangulation for three-dimensional reconstruction. In contrast, due to the binocular system structure, the stereo vision method overcomes the application limitations in the phase-height mapping method; and the calibration process of the stereo vision method is more flexible, and it is only necessary to place the target in the measurement space. The location of the system can be completed. However, in the reconstruction process, the stereo vision method needs to perform a series of coordinate transformations, especially the corresponding points between the search camera and the projector, which greatly increases the computational complexity and time cost, and significantly reduces the efficiency of the three-dimensional reconstruction.

Summary of the invention

The technical problem to be solved by the present invention is to provide an efficient phase-three-dimensional mapping method and system based on fringe projection profilometry, which aims to directly map the phase to the three-dimensional coordinates of the spatial point, thereby realizing efficient three-dimensional reconstruction of the object to be tested.

The present invention provides an efficient phase-three-dimensional mapping method based on fringe projection profilometry based on a binocular system, the binocular system comprising a projection device and an imaging device, the method comprising:

Step S1, using a projection device to project a stripe sequence onto the surface of the object to be tested, and using an imaging device to acquire a deformed fringe pattern modulated by the surface of the object to be tested, and calculating a phase of all pixel points on the image of the imaging device according to the deformed fringe pattern. ;

Step S2, searching for a phase-three-dimensional mapping coefficient corresponding to each pixel point in a preset phase-three-dimensional mapping coefficient lookup table, and substituting the phase of each pixel point and the corresponding phase-three-dimensional mapping coefficient into a preset The phase-three-dimensional mapping function calculates the three-dimensional coordinates of the object points corresponding to each pixel on the image of the imaging device.

Further, the phase-three-dimensional mapping function is:

Where (X _c (φ _c ), Y _c (φ _c ), Z _c (φ _c )) is the three-dimensional coordinate of the spatial point of the object to be measured, φ _c is the phase corresponding to the pixel point, a _n , b _n , c _n , c _X , c _Y , c _Z are phase-to-three-dimensional mapping coefficients, wherein a _n , b _n , c _n are phase-three-dimensional mapping functions X _c (φ _c ), Y _c (φ _c ), respectively. , the coefficient of the polynomial in Z _c (φ _c ), c _X , c _Y , c _Z are the constants in the phase-three-dimensional mapping function X _c (φ _c ), Y _c (φ _c ), Z _c (φ _c ), respectively item.

Further, before the step S1, the method further includes:

Step S01, the system parameters of the binocular system are calibrated by a ray re-projection strategy;

Step S02, combining the system parameters, calibrating the phase-three-dimensional mapping coefficients by using a sampling mapping strategy, and obtaining a phase-three-dimensional mapping coefficient lookup table.

Further, the step S01 specifically includes:

Step S011, placing a target marked with a marker point in a calibration space, acquiring an image of the imaging device of the target by using the imaging device, and then projecting an orthogonal stripe sequence onto the target by using a projection device, An imaging device acquires an orthogonal fringe pattern modulated by a target surface on which the marker point is printed;

Step S012, extracting coordinates of the pixel points of the marker point on the image of the imaging device;

Step S013, calculating a quadrature phase by the orthogonal fringe pattern, and determining coordinates of the pixel points of the marker point on the image of the projection device by using the quadrature phase;

Step S014, by backprojecting the stereoscopic vision model, combining the system parameters to determine the spatial ray of the pixel point on the image of the imaging device and the coordinates of the pixel on the projection device image, respectively, and back projection by the preset ray re-projection. The policy adjusts the system parameter, and uses the system parameter when the sum of the distances of the marker points to the corresponding two spatial rays is the minimum as the system parameter of the binocular system.

Further, the step S02 specifically includes:

Step S021, determining, by using the calibrated system parameters, a spatial ray of a reverse projection of coordinates of any pixel on the image of the imaging device;

Step S022, sampling along the spatial ray in the calibration space, obtaining a series of spatial sampling points, respectively projecting the series of spatial sampling points onto the image of the projection device to obtain a corresponding phase value;

Step S023, using the phase values corresponding to the series of sampling points and the three-dimensional coordinates of the series of sampling points to fit the phase-three-dimensional mapping coefficient of the any pixel point;

Step S024, repeating steps S021-S023 for each pixel on the image of the imaging device to obtain a phase-three-dimensional mapping coefficient of each pixel, and generating a phase-three-dimensional mapping coefficient lookup table.

The present invention also provides an efficient phase-three-dimensional mapping system based on fringe projection profilometry based on a binocular system comprising a projection device and an imaging device, the phase-three-dimensional mapping system include:

a phase acquisition module, configured to project a stripe sequence to a surface of the object to be tested by using a projection device, and acquire a deformed fringe pattern modulated by the surface of the object to be tested by using an imaging device, and calculate all pixels on the image of the imaging device according to the deformed fringe pattern The phase of the point;

a three-dimensional coordinate acquiring module, configured to find a phase-three-dimensional mapping coefficient corresponding to each pixel point in a preset phase-three-dimensional mapping coefficient lookup table, and map the phase and corresponding phase-three-dimensional mapping of each pixel point The coefficients are substituted into a preset phase-three-dimensional mapping function to calculate the three-dimensional coordinates of the object points corresponding to each pixel on the image of the imaging device.

Further, the phase-three-dimensional mapping function is:

Further, the phase-three-dimensional mapping system further includes a calibration module, the calibration module is configured to calibrate the phase-three-dimensional mapping coefficient, and the calibration module includes a first standard stator module and a second standard stator module;

The first standard stator module is configured to calibrate system parameters of the binocular system by a ray re-projection strategy;

The second standard stator module is configured to combine the system parameters, calibrate the phase-three-dimensional mapping coefficient by using a sampling mapping strategy, and obtain a phase-three-dimensional mapping coefficient lookup table.

Further, the first standard stator module specifically includes:

a collection sub-module, configured to place a target marked with a marker point in a calibration space, acquire an image of the imaging device of the target by using the imaging device, and then project an orthogonal stripe sequence onto the target by using a projection device, Acquiring, by the imaging device, an orthogonal fringe pattern modulated by a target surface on which the marker point is printed;

a first coordinate acquisition sub-module, configured to extract coordinates of a pixel point of the marker point on the image of the imaging device;

a second coordinate acquisition submodule, configured to calculate a quadrature phase by using the orthogonal fringe pattern, and determine coordinates of the pixel point of the marker point on the image of the projection device by using the quadrature phase;

The system parameter standard stator module is configured to determine the spatial ray of the pixel point on the image of the imaging device and the coordinates of the pixel on the projection device image by the back projection stereoscopic vision model, combined with the system parameters, and pass the pre-projection The set ray re-projection strategy adjusts the system parameters, and uses the system parameter when the sum of the distances of the marker points to the corresponding two spatial rays is the minimum as the system parameter of the binocular system.

Further, the second standard stator module specifically includes:

a spatial ray projection sub-module for determining a spatial ray of a reverse projection of coordinates of any pixel on the image of the imaging device by using the calibrated system parameter;

a phase value acquisition sub-module, configured to sample along the spatial ray in the calibration space, to obtain a series of spatial sampling points, and respectively project the series of spatial sampling points onto the image of the projection device to obtain a corresponding phase value;

The phase-three-dimensional mapping coefficient standard stator module is configured to fit the phase-three-dimensional mapping coefficient of the any pixel point by using the phase value corresponding to the series of sampling points and the three-dimensional coordinates of the series of sampling points;

The phase-three-dimensional mapping coefficient lookup table acquisition sub-module is configured to process each pixel on the image of the imaging device to obtain a phase-three-dimensional mapping coefficient of each pixel, and generate a phase-three-dimensional mapping coefficient lookup table.

Compared with the prior art, the present invention has the beneficial effects that the high-efficiency phase-three-dimensional mapping method and system based on fringe projection profilometry are first found in a preset phase-three-dimensional mapping coefficient lookup table. The phase-three-dimensional mapping coefficient corresponding to each pixel point, and then the phase of each pixel point and the corresponding phase-three-dimensional mapping coefficient are substituted into the phase-three-dimensional mapping function, and the three-dimensional coordinates of the object point corresponding to each pixel point can be obtained. The three-dimensional coordinates of the surface of the object to be tested are obtained; the high-efficiency three-dimensional reconstruction of the object to be tested can be achieved by the above method, and the method satisfies the requirements of high-efficiency and high-precision three-dimensional digital imaging and measurement based on fringe projection profilometry.

DRAWINGS

FIG. 1 is a phase-to-three-dimensional mapping coefficient of a phase-three-dimensional mapping function according to an embodiment of the present invention. Schematic diagram of the process of calibration;

2 is a schematic flow chart of an efficient phase-to-three-dimensional mapping method based on fringe projection profilometry according to an embodiment of the present invention;

3 is a back projection stereo vision model of a binocular system constructed by an imaging device-projection device according to an embodiment of the present invention;

4 is a schematic diagram showing coordinate distribution of a planar target mark point on a camera image and a projector image according to an embodiment of the present invention;

Figure 5 is a phase diagram of a plaster image provided by an embodiment of the present invention;

6 is a three-dimensional model diagram of a plaster image provided by an embodiment of the present invention;

7 is a schematic block diagram of an efficient phase-three-dimensional mapping system based on fringe projection profilometry according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a module for calibrating a phase-three-dimensional mapping coefficient of a phase-three-dimensional mapping function according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The main implementation idea of the present invention is: deriving the mapping relationship between phase and three-dimensional coordinates based on the back projection stereo vision model, that is, deriving the phase-three-dimensional mapping function; based on the phase-three-dimensional mapping function, a pre-designed one A two-step calibration algorithm, including ray re-projection calibration and sampling mapping calibration, to obtain phase-three-dimensional mapping coefficients; and bringing phase and the phase-three-dimensional mapping coefficients into the phase-three-dimensional mapping function to obtain a surface of the object to be tested The three-dimensional coordinates, and in turn achieve efficient three-dimensional reconstruction of the object to be measured.

The high-efficiency phase-three-dimensional mapping method based on fringe projection profilometry is specifically described below, and the fringe projection profiling is based on a binocular system including a projection device and an imaging device; As shown, before performing the method, there is also a pre-processing step; that is, before step S1, further comprising:

Step S0, calibrating the phase-three-dimensional mapping coefficient of the phase-three-dimensional mapping function;

Specifically, the mapping coefficient of the phase-three-dimensional mapping function is a flexible and accurate calibration of the phase-three-dimensional mapping coefficient realized by pre-designing a two-step calibration algorithm including ray re-projection calibration and sampling mapping calibration; The purpose is to determine the phase-three-dimensional mapping coefficient of each pixel in the image of the imaging device, and to generate a phase-three-dimensional mapping coefficient lookup table of the pixel index.

The step S0 includes:

Specifically, the ray re-projection refers to: projecting the coordinates of the pixel point back to a spatial ray through the system parameters of the binocular system; the ray re-projection strategy refers to: minimizing the ray re-projection error, that is, adjusting the binocular The system parameters of the system minimize the error distance from the object point to the back projection ray.

Specifically, the step S01 specifically includes:

Step S011, placing a target marked with a marker point in a calibration space, acquiring an image of the imaging device of the target by using the imaging device, and then projecting an orthogonal stripe sequence onto the target by using a projection device, The imaging device acquires an orthogonal fringe pattern modulated by the target surface on which the marker points are printed.

Specifically, if the target is a planar target, the planar target is placed at different positions, and the imaging device image of the target is acquired by the imaging device at each position, and then projected by the projection device. An orthogonal stripe sequence is applied to the target, and an orthogonal fringe pattern modulated by the target surface on which the marker point is printed is acquired by the imaging device.

Step S014, by backprojecting the stereoscopic vision model, combining the system parameters to determine the spatial ray of the pixel point on the image of the imaging device and the coordinates of the pixel on the projection device image, respectively, and back projection by the preset ray re-projection. The policy adjusts the system parameters to correspond to the flag points The system parameter when the sum of the distances of the two spatial rays is the smallest is used as a system parameter for calibrating the binocular system.

Specifically, the binocular system composed of the projection device and the imaging device employs a back projection stereoscopic vision model; the model means, in an ideal case, the coordinates of the pixel points on the image of the projection device corresponding to the same object point and the image of the imaging device The coordinates of the upper pixel point intersect the object point through the back projection of the two spatial rays, which conforms to the physical process of stereoscopic three-dimensional imaging.

Specifically, sampling mapping refers to sampling on a reverse projection ray of any pixel on the image of the imaging device to obtain a series of spatial sampling points, and mapping the series of sampling points onto the image of the projection device to obtain a corresponding image. Phase value; the sampling mapping strategy refers to fitting the phase-three-dimensional mapping coefficient of the pixel point by using the phase value corresponding to the series of sampling points and the three-dimensional coordinates corresponding to the series of sampling points.

The step S02 specifically includes:

Specifically, the phase-three-dimensional mapping coefficient of each pixel in the image of the imaging device is determined by the above calibration process; the phase corresponding to each pixel on the image of the imaging device can be detected by the phase-three-dimensional mapping coefficient lookup table. The mapping coefficient, the phase-three-dimensional mapping coefficient corresponding to each pixel point mentioned here refers to the phase-three-dimensional mapping coefficient corresponding to the coordinates of each pixel point.

The following is a detailed description of the implementation of this efficient fringe-three-dimensional mapping method based on fringe projection profilometry. Steps, as shown in FIG. 2, the method includes:

Specifically, the phase-three-dimensional mapping coefficient lookup table is a phase-three-dimensional mapping coefficient lookup table of a pixel point index; in the phase-three-dimensional mapping coefficient lookup table, the corresponding phase-three-dimensional mapping coefficient is found by a pixel point index.

The phase-three-dimensional mapping function is:

The following describes the derivation process of the above formula (1), ie, the phase-three-dimensional mapping function:

The phase-three-dimensional mapping function is based on the mapping relationship between the phase and the three-dimensional coordinates derived from the back projection stereo vision model. As shown in FIG. 3, the back projection stereo vision model is expressed as:

Where X _w and X _c are the coordinates of the object point in the world coordinate system and the imaging device coordinate system, respectively, and x _c and x _p are the pixel points of the object point on the imaging device image and the projection device image, respectively, x' _d and x' _p is the distortion coordinate corresponding to x _c and x _p respectively, and m _c and m _p are the coordinates of the pixel on the imaging device image and the projection device image, respectively, and R _c and t _c are the coordinate of the world coordinate system to the imaging device, respectively. The rotation matrix and the translation vector of the system, R _s and t _s are the rotation matrix and the translation vector of the imaging device coordinate system to the projection device coordinate system, respectively, and K _c and K _p are the projection matrix of the imaging device and the projection device, respectively, k _c and k _p is the lens distortion coefficient vector of the imaging device and the projection device, respectively, λ _c and λ _p are scale factors, I represents the identity matrix, and 0 is the zero vector.

Indicates homogeneous coordinates. Usually, R, t represents an external parameter, and K, k represents an internal parameter.

In the present invention, assuming that vertical stripes are projected, the phase value φ _p on the image of the projection device is proportional to the abscissa u _p . For a pair of corresponding points m _c and m _{p of the} imaging device and the projection device, their phase values are equal, that is, φ _p = φ _c . Therefore φ _c to u _p is a linear mapping:

Among them, the superscript L represents a linear mapping relationship. According to the polar line geometry constraint, the pixel point m _c on the image of the imaging device corresponds to a line I _p on the image of the projection device. Due to lens distortion, the actual polar line is a curved curve I' _p . Since _I'p is a continuous curve, the curve can be approximated as a polynomial curve according to the Weierstrass approximation theorem. Since m _{p is} on I' _p , the image coordinates u _p to v _p are polynomial mappings:

Among them, the superscript P represents a polynomial mapping relationship. According to formula (2), the image point m _{p is} converted into the projection device coordinate system, that is, x' _p = (x' _p , y' _p ) ^T , expressed as

Equation (5) contains a linear mapping from (u _p , v _p ) to x′ _p and y′ _p , expressed as:

Correction from the distorted image point x' _p to the undistorted image point x _p is a polynomial mapping process, expressed as:

The two spatial rays projecting back from the image points x _c and x _p meet at the spatial point X _c . According to the back projection stereo vision model, ie equation (2), the ray intersection is expressed as:

From the formula (8), the three-dimensional coordinates of the spatial point can be solved, expressed as:

Where r _ij and t _i are elements of R _s and t _s , respectively.

In the present invention, the binocular system remains stationary, and the pixel points on the image of a particular imaging device, R _s , t _s and image coordinates x _c and y _c are determined. Therefore, the spatial coordinates X _c , Y _c and Z _c are functions of x _p , respectively, expressed as:

Substituting equations (3), (4), (6), and (7) into (10), equation (1) can be derived.

By obtaining the three-dimensional coordinates of the object point on the surface of the object to be tested by the above method, the three-dimensional shape of the object to be tested can be reconstructed.

The implementation process of the above-described stripe projection profiling-based efficient phase-three-dimensional mapping method is described in the following. In the embodiment of the present invention, the imaging device is a camera, the projection device is a projector, and the object to be tested is a plaster image:

Before calculating the three-dimensional coordinates of the object point, the phase-three-dimensional mapping coefficient is first calibrated. Specifically, the binocular system consisting of the camera and the projector is calibrated according to steps S011-S014 using the planar target, and the system parameters are optimized; The system parameters are fitted to the phase-three-dimensional mapping coefficients according to steps S021-S024 to generate a phase-three-dimensional mapping coefficient lookup table of the pixel point index, that is, the calibration step is completed. When calculating the three-dimensional coordinates of the object point, the sinusoidal stripe sequence is first projected onto the surface of the plaster image, and the deformed fringe pattern is acquired by the camera, and the phase of all the pixel points on the camera image is calculated according to the deformed fringe pattern; then, the phase-three-dimensional mapping coefficient is obtained. The corresponding phase-three-dimensional mapping coefficient is found by the pixel index in the lookup table, and the phase value of the pixel and the corresponding phase-three-dimensional mapping coefficient are substituted into the formula (1) to calculate the three-dimensional coordinates, and finally the three-dimensional model is generated.

4 is a coordinate distribution of the planar target mark point on the camera image and the projector image in one position, FIG. 5 is a phase diagram of the plaster image, and FIG. 6 is a three-dimensional model diagram of the plaster image.

The efficient phase-three-dimensional mapping method based on fringe projection profilometry provided by the invention satisfies the requirements of high-efficiency and high-precision three-dimensional digital imaging and measurement.

The high-efficiency phase-three-dimensional mapping system based on fringe projection profilometry is described in detail below. The fringe projection profiling is based on a binocular system comprising a projection device and an imaging device; the phase-three-dimensional mapping system is working Previously, calibration is required; therefore, as shown in FIG. 7, the phase-three-dimensional mapping system includes a calibration module 1 for calibrating phase-three-dimensional mapping coefficients, the calibration module including the first a standard stator module 11 and a second standard stator module 12;

The first standard stator module 11 is configured to calibrate system parameters of the binocular system by a ray re-projection strategy;

As shown in FIG. 8, the first standard stator module 11 specifically includes:

a collection sub-module 111, configured to place a target marked with a marker point in a calibration space, acquire an image of the imaging device of the target by using the imaging device, and then project an orthogonal stripe sequence onto the target by using a projection device Obtaining, by the imaging device, an orthogonal fringe pattern modulated by a target surface on which the marker point is printed;

a first coordinate acquisition sub-module 112, configured to extract an image of the marker point on the image of the imaging device The coordinates of the prime point;

a second coordinate acquisition sub-module 113, configured to calculate a quadrature phase by using the orthogonal fringe pattern, and determine coordinates of the pixel points of the marker point on the image of the projection device by using the quadrature phase;

The system parameter standard stator module 114 is configured to determine, by the back projection stereo vision model, the spatial ray of the pixel point on the image of the imaging device and the coordinates of the pixel point on the image of the projection device, respectively, by using the system parameter to determine the spatial ray of the marker point on the image of the imaging device. The preset ray re-projection strategy adjusts the system parameters, and uses the system parameter when the sum of the distances of the marker points to the corresponding two spatial rays is the minimum as the system parameter of the binocular system.

The second standard stator module 12 is configured to combine the system parameters, calibrate the phase-three-dimensional mapping coefficients by using a sampling mapping strategy, and obtain a phase-three-dimensional mapping coefficient lookup table.

The second standard stator module 12 specifically includes:

a spatial ray projection sub-module 121, configured to determine, by using the calibrated system parameters, a spatial ray of a reverse projection of coordinates of any pixel on the image of the imaging device;

The phase value acquisition sub-module 122 is configured to sample along the spatial ray in the calibration space to obtain a series of spatial sampling points, and respectively project the series of spatial sampling points onto the image of the projection device to obtain a corresponding phase value;

The phase-three-dimensional mapping coefficient standard stator module 123 is configured to fit the phase-three-dimensional mapping coefficient of the any pixel point by using the phase value corresponding to the series of sampling points and the three-dimensional coordinates of the series of sampling points;

The phase-three-dimensional mapping coefficient lookup table acquisition sub-module 124 is configured to process each pixel point on the image of the imaging device to obtain a phase-three-dimensional mapping coefficient of each pixel point, and generate a phase-three-dimensional mapping coefficient lookup table. .

The phase-three-dimensional mapping system further includes:

The phase acquisition module 2 is configured to project a stripe sequence onto the surface of the object to be tested by using the projection device, and acquire a deformed fringe pattern modulated by the surface of the object to be tested by using an imaging device, and calculate all the images on the image of the imaging device according to the deformed fringe pattern. The phase of the pixel;

a three-dimensional coordinate acquiring module 3, configured to find each in a preset phase-three-dimensional mapping coefficient lookup table a phase-three-dimensional mapping coefficient corresponding to one pixel, and substituting the phase of each pixel and the corresponding phase-three-dimensional mapping coefficient into a preset phase-three-dimensional mapping function, thereby calculating each pixel on the image of the imaging device The corresponding three-dimensional coordinates of the object point.

Specifically, the phase-three-dimensional mapping function is:

The high-efficiency phase-three-dimensional mapping system based on fringe projection profilometry provided by the invention satisfies the requirements of high-efficiency and high-precision three-dimensional digital imaging and measurement.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

An efficient phase-three-dimensional mapping method based on fringe projection profilometry, the fringe projection profiling based on a binocular system, the binocular system comprising a projection device and an imaging device, wherein the method comprises:

Step S1, using a projection device to project a stripe sequence onto the surface of the object to be tested, and using an imaging device to acquire a deformed fringe pattern modulated by the surface of the object to be tested, and calculating a phase of all pixel points on the image of the imaging device according to the deformed fringe pattern. ;

Step S2, searching for a phase-three-dimensional mapping coefficient corresponding to each pixel point in a preset phase-three-dimensional mapping coefficient lookup table, and substituting the phase of each pixel point and the corresponding phase-three-dimensional mapping coefficient into a preset The phase-three-dimensional mapping function calculates the three-dimensional coordinates of the object points corresponding to each pixel on the image of the imaging device.
The efficient phase-to-three-dimensional mapping method according to claim 1, wherein the phase-three-dimensional mapping function is:

Where (X c (φ c ), Y c (φ c ), Z c (φ c )) is the three-dimensional coordinate of the spatial point of the object to be measured, φ c is the phase corresponding to the pixel point, a n , b n , c n , c X , c Y , c Z are phase-to-three-dimensional mapping coefficients, wherein a n , b n , c n are phase-three-dimensional mapping functions X c (φ c ), Y c (φ c ), respectively. , the coefficient of the polynomial in Z c (φ c ), c X , c Y , c Z are the constants in the phase-three-dimensional mapping function X c (φ c ), Y c (φ c ), Z c (φ c ), respectively item.
The high-efficiency phase-three-dimensional mapping method according to claim 1, wherein before the step S1, the method further comprises:

Step S01, the system parameters of the binocular system are calibrated by a ray re-projection strategy;

Step S02, combining the system parameters, calibrating the phase-three-dimensional mapping coefficients by using a sampling mapping strategy, and obtaining a phase-three-dimensional mapping coefficient lookup table.
The efficient phase-to-three-dimensional mapping method according to claim 3, wherein said step S01 specifically includes:

Step S011, placing a target marked with a marker point in a calibration space, acquiring an image of the imaging device of the target by using the imaging device, and then projecting an orthogonal stripe sequence onto the target by using a projection device, An imaging device acquires an orthogonal fringe pattern modulated by a target surface on which the marker point is printed;

Step S012, extracting coordinates of the pixel points of the marker point on the image of the imaging device;

Step S013, calculating a quadrature phase by the orthogonal fringe pattern, and determining coordinates of the pixel points of the marker point on the image of the projection device by using the quadrature phase;

Step S014, by backprojecting the stereoscopic vision model, combining the system parameters to determine the spatial ray of the marker point on the image of the imaging device and the coordinates of the pixel on the projection device image, respectively, and back projection by the preset ray re-projection. The policy adjusts the system parameter, and uses the system parameter when the sum of the distances of the marker points to the corresponding two spatial rays is the minimum as the system parameter of the binocular system.
The high-efficiency phase-three-dimensional mapping method according to claim 3 or 4, wherein the step S02 specifically includes:

Step S021, determining, by using the calibrated system parameters, a spatial ray of a reverse projection of coordinates of any pixel on the image of the imaging device;

Step S022, sampling along the spatial ray in the calibration space, obtaining a series of spatial sampling points, respectively projecting the series of spatial sampling points onto the image of the projection device to obtain a corresponding phase value;

Step S023, using the phase values corresponding to the series of sampling points and the three-dimensional coordinates of the series of sampling points to fit the phase-three-dimensional mapping coefficient of the any pixel point;

Step S024, repeating steps S021-S023 for each pixel on the image of the imaging device to obtain a phase-three-dimensional mapping coefficient of each pixel, and generating a phase-three-dimensional mapping coefficient lookup table.
An efficient phase-three-dimensional mapping system based on fringe projection profilometry based on a binocular system, the binocular system comprising a projection device and an imaging device, wherein the phase-three-dimensional mapping system comprises :

a phase acquisition module for projecting a stripe sequence onto a surface of the object to be tested by using a projection device, and utilizing The imaging device collects a deformed fringe pattern modulated by the surface of the object to be tested, and calculates a phase of all pixel points on the image of the imaging device according to the deformed fringe pattern;

a three-dimensional coordinate acquiring module, configured to find a phase-three-dimensional mapping coefficient corresponding to each pixel point in a preset phase-three-dimensional mapping coefficient lookup table, and map the phase and corresponding phase-three-dimensional mapping of each pixel point The coefficients are substituted into a preset phase-three-dimensional mapping function to calculate the three-dimensional coordinates of the object points corresponding to each pixel on the image of the imaging device.
The high efficiency phase-to-three-dimensional mapping system of claim 6 wherein said phase-to-three-dimensional mapping function is:

Where (X c (φ c ), Y c (φ c ), Z c (φ c )) is the three-dimensional coordinate of the spatial point of the object to be measured, φ c is the phase corresponding to the pixel point, a n , b n , c n , c X , c Y , c Z are phase-to-three-dimensional mapping coefficients, wherein a n , b n , c n are phase-three-dimensional mapping functions X c (φ c ), Y c (φ c ), respectively. , the coefficient of the polynomial in Z c (φ c ), c X , c Y , c Z are the constants in the phase-three-dimensional mapping function X c (φ c ), Y c (φ c ), Z c (φ c ), respectively item.
The high-efficiency phase-three-dimensional mapping system according to claim 6, wherein the phase-three-dimensional mapping system further comprises a calibration module, the calibration module is configured to calibrate the phase-three-dimensional mapping coefficient, and the calibration module comprises a first standard stator module and a second standard stator module;

The first standard stator module is configured to calibrate system parameters of the binocular system by a ray re-projection strategy;

The second standard stator module is configured to combine the system parameters, calibrate the phase-three-dimensional mapping coefficient by using a sampling mapping strategy, and obtain a phase-three-dimensional mapping coefficient lookup table.
The high-efficiency phase-three-dimensional mapping system of claim 8, wherein the first standard stator module comprises:

a collection sub-module, configured to place a target marked with a marker point in a calibration space, acquire an image of the imaging device of the target by using the imaging device, and then project an orthogonal stripe sequence onto the target by using a projection device, Acquiring, by the imaging device, an orthogonal fringe pattern modulated by a target surface on which the marker point is printed;

a first coordinate acquisition sub-module, configured to extract coordinates of a pixel point of the marker point on the image of the imaging device;

a second coordinate acquisition submodule, configured to calculate a quadrature phase by using the orthogonal fringe pattern, and determine coordinates of the pixel point of the marker point on the image of the projection device by using the quadrature phase;

The system parameter standard stator module is configured to determine the spatial ray of the pixel point on the image of the imaging device and the coordinates of the pixel on the projection device image by the back projection stereoscopic vision model, combined with the system parameters, and pass the pre-projection The set ray re-projection strategy adjusts the system parameters, and uses the system parameter when the sum of the distances of the marker points to the corresponding two spatial rays is the minimum as the system parameter of the binocular system.
The high-efficiency phase-three-dimensional mapping system according to claim 8 or 9, wherein the second standard stator module comprises:

a spatial ray projection sub-module for determining a spatial ray of a reverse projection of coordinates of any pixel on the image of the imaging device by using the calibrated system parameter;

a phase value acquisition sub-module, configured to sample along the spatial ray in the calibration space, to obtain a series of spatial sampling points, and respectively project the series of spatial sampling points onto the image of the projection device to obtain a corresponding phase value;

The phase-three-dimensional mapping coefficient standard stator module is configured to fit the phase-three-dimensional mapping coefficient of the any pixel point by using the phase value corresponding to the series of sampling points and the three-dimensional coordinates of the series of sampling points;

The phase-three-dimensional mapping coefficient lookup table acquisition sub-module is configured to process each pixel on the image of the imaging device to obtain a phase-three-dimensional mapping coefficient of each pixel, and generate a phase-three-dimensional mapping coefficient lookup table.