阅读说明：本技术 一种基于投影平面的彩色编码光栅串扰补偿方法 (Color coding grating crosstalk compensation method based on projection plane ) 是由 刘飞 吴明雄 吴高旭 吴延雪 张圣明 杨时超 严谨 罗惠方 张茵楠 于 2019-06-04 设计创作，主要内容包括：本发明公开了一种基于投影平面的彩色编码光栅串扰补偿方法,该方法通过分别投影传统黑白光栅和彩色光栅(水平和竖直方向)于一个标准平板上,基于投影坐标转换公式建立灰度绝对相位和彩色绝对相位之间的误差查找表err(u<Sub>p</Sub>,v<Sub>p</Sub>)。接着投影彩色光栅于待测实物上,解包裹相位得到实物的绝对相位。通过在投影平面寻找对应点相位值的补偿量,之后便可以获得串扰补偿后的相位。不同于其他彩色通道补偿方法,该方法通过建立一个误差查找表,在投影平面上利用点对点的全灰度值补偿,有效地抑制和修正了彩色串扰误差。本发明方法提出了一种可行的串扰补偿算法,保证彩色光栅轮廓术三维测量的精度和优点,可以应用于快速三维测量领域。(The invention discloses a color coding grating crosstalk compensation method based on a projection plane, which comprises the steps of respectively projecting a traditional black-white grating and a color grating (in the horizontal direction and the vertical direction) on a standard flat plate, and establishing an error lookup table err (u) between a gray absolute phase and a color absolute phase based on a projection coordinate conversion formula p ,v p ). And then projecting the color grating on the object to be detected, and unwrapping the phase to obtain the absolute phase of the object. The phase after crosstalk compensation can be obtained by searching the compensation quantity of the phase value of the corresponding point on the projection plane. Unlike other color channel compensation methods, the method effectively suppresses and corrects color crosstalk errors by building an error lookup table and using point-to-point full gray value compensation on the projection plane. The method of the invention provides a feasible crosstalk compensation algorithm, ensures the precision and the advantages of the three-dimensional measurement of the color grating profilometry, and can be appliedIn the field of rapid three-dimensional measurement.)

1. A color coding grating crosstalk compensation method based on a projection plane is characterized in that: the method comprises the following steps:

step 1: respectively projecting 3-frequency 3-step black and white stripe images (horizontal and vertical) and color stripe images (horizontal and vertical) on a standard flat plate, and respectively collecting the two groups of images;

step 2: performing channel separation according to the horizontal and vertical color images collected in the step 1, and separating the color deformation fringe pattern into three channels R \ G \ B to obtain 18(9+9) single-channel images;

and step 3: and respectively unwrapping the phases of the two groups of images to obtain the absolute phases of the black-white stripes and the color stripes: gray _ PHI_u、Gray_PHI_νAnd RGB _ PHI_u、RGB_PHI_ν. Each group of absolute phases can be respectively converted into a projection plane by a projection plane conversion equation to obtain projection plane coordinates of black-white stripes and color stripes: gray (u)_p,v_p) And RGB (u)_p,v_p)；

And 4, step 4: by taking the difference between the two sets of absolute phases in step 3, an error lookup table err (u) between the conventional black and white stripes and the color stripes can be established_p,v_p)；

And 5: and (3) projecting the color fringe pattern on the surface of the object to be detected according to the method flow of the step (1) and the step (2), and acquiring to obtain a color deformation fringe image. And obtaining a real object phase coordinate based on the projection plane through a unwrapping algorithm and a projection plane conversion equation: RGB _ obj (u)_p,v_p)；

Step 6: RGB (u) calculated from steps 3 and 4_p,v_p) And err (u)_p,v_p) For the phase coordinates RGB _ obj (u) of the object to be measured in step 5_p,v_p) Point-to-point crosstalk compensation is performed. For RGB _ obj (u) based on shortest distance search algorithm_p,v_p) At a certain point M (u)_p,v_p) Can be in RGB (u)_p,v_p) Searching for a point P_min(u_p,v_p) As the shortest distance coordinate, corresponds to the error lookup table err (u) in the camera coordinate system_p,v_p) Middle point N (u)_p,v_p) Is point M (u)_p,v_p) The error compensation amount of (1);

and 7: according to the error compensation quantity of the corresponding point obtained in the step 6, the object RGB _ obj (u) to be detected is subjected to the projection plane coordinate system_p,v_p) Compensating, and obtaining an absolute phase PHI through reduction of a projection plane conversion equation_hAnd PHI_ν(vertical direction PHI therein)_v) And further reconstructing the three-dimensional shape.

2. The method of claim 1, wherein the crosstalk compensation is performed by a color coding grating based on a projection plane, and the method comprises: wherein in step 1, the black and white stripesThe frequency is consistent with the coding fringe period of the color fringe, the high frequency, the middle frequency and the low frequency should be reasonable, and the frequency value is doubled as much as possible. The light intensity value of the projection grating modulated by each channel in the 3-frequency 3-step color coding stripe should satisfy: i is_R＞I_G＝I_B。

3. The method of claim 1, wherein the crosstalk compensation is performed by a color coding grating based on a projection plane, and the method comprises: in step 1, the encoding method of the color fringe pattern and the light intensity value of each channel projection are shown as the following formulas (1) to (3):

I_R(x,y)＝A_R(x,y)+B_R(x,y)cos[φ(x,y)-2π/3], (1)

I_G(x,y)＝A_G(x,y)+B_G(x,y)cos[φ(x,y)], (2)

I_B(x,y)＝A_B(x,y)+B_B(x,y)cos[φ(x,y)+2π/3]. (3)

it I_i(i ═ R \ G \ B) is the modulated light intensity values of the three channels R \ G \ B;

A_i(i ═ R \ G \ B) is the background light intensity of three channels R \ G \ B, B_i(i ═ R \ G \ B) is the modulation amplitude;

phi (x, y) is the wrapped phase value of the object to be measured.

4. The method of claim 1, wherein the crosstalk compensation is performed by a color coding grating based on a projection plane, and the method comprises: wherein the projection plane transformation equation described in step 2 can be obtained by the following equations (4) to (5):

wherein u is_pAnd v_pA line in the projection plane (DMD image) for the u and v directions, respectively;

PHI_v、PHI_habsolute phase values for vertical and horizontal directions;

N_vand N_hThe number of the stripes of the grating image;

w and H are resolutions in horizontal and vertical directions of the projected image of the image, respectively.

5. The method of claim 1, wherein the crosstalk compensation is performed by a color coding grating based on a projection plane, and the method comprises: wherein the error lookup table err (u) between black and white stripes and color stripes in step 4_p,v_p) The following can be obtained from equation (6):

err(u_p,v_p)＝Gray(u_p,v_p)-RGB(u_p,v_p). (6)

wherein, Gray (u)_p,v_p) And RGB (u)_p,v_p) The absolute phase values of the black and white stripes and the color stripes, respectively, in the projection plane.

6. The method of claim 6, wherein the crosstalk compensation is performed by a color-coded grating based on a projection plane, and the method comprises: wherein the shortest distance search algorithm described in step 6, wherein for RGB _ obj (u)_p,v_p) At a certain point M (u)_p,v_p) Can be in RGB _ (u)_p,v_p) Searching for a point P_min(u_p,v_p) As the shortest distance coordinate. P_min(u_p,v_p) Is iteratively calculated, i.e. P_i(u_p,v_p) And M (u)_p,v_p) When the difference value of (A) is minimum, finding the corresponding point as P_min(u_p,v_p)。

7. The method of claim 1, wherein the crosstalk compensation is performed by a color coding grating based on a projection plane, and the method comprises: wherein in step 7, the object to be tested RGB _ obj (u) is measured_p,v_p) Compensating the absolute phase value RGB _ ideal (u)_p,v_p) The following can be obtained from equation (7):

RGB_ideal(u_p,v_p)＝RGB(u_p,v_p)+err(u_p,v_p). (7)

8. the method of claim 7, wherein the crosstalk compensation is performed by a color-coded grating based on a projection plane, and the method comprises: wherein, according to the formulas (4) and (5), RGB _ ideal (u) is restored through the projection plane conversion equation_p,v_p) The absolute phase PHI obtained thereafter_uAnd PHI_νTaking the absolute phase PHI of the vertical direction therein_v。

According to the method, after the unwrapped absolute phase is obtained, the three-dimensional morphology can be easily reconstructed. Thereby realizing the high-precision and quick measurement of the three-dimensional shape of the measured object.

Technical Field

The invention relates to an optical three-dimensional shape measurement, reconstruction and structured light technology. The invention relates to a color grating error compensation method, in particular to a color coding grating crosstalk compensation method based on a projection plane.

Background

With the development of network communication technology and the expansion of production and living requirements, a simple and convenient method for measuring the three-dimensional shape of an object is needed in various industries. Three-dimensional measurement is divided into contact type and non-contact type according to whether the measurement is in contact with an object to be measured or not, and the non-contact type three-dimensional measurement technology has the advantages which are not possessed by the traditional contact type measurement technology under the condition of the same high precision: such as surface protection of measuring workpieces, measurement of large-sized workpieces, less time consumption, portability and the like. In recent years, non-contact three-dimensional measurement technology is increasingly applied to the fields of cultural relic protection, reverse engineering, virtual reality and the like.

The three-dimensional reconstruction technology is an extension of the three-dimensional measurement technology, acquires the three-dimensional shape information of a target object by a certain method, and reconstructs the three-dimensional profile of the object by certain algorithm processing.

The technology of measuring the three-dimensional topography of the surface of an object based on various structured lights is emerging continuously, and the technology is applied to different fields according to respective characteristics. The fringe pattern design and implementation accuracy is high, the automation degree is high, and the recognition is easy, so that the projection pattern in the optical three-dimensional measurement mainly tends to use the fringe pattern. The fringe structure light projection method is an active optical measurement method based on the principle of triangulation. The color projection pattern can increase the number of basic codes and ensure the code uniqueness, and reconstruct a moving object, so the color compound sine stripe projection technology is widely researched and applied along with the development of color high-precision projectors and Charge Coupled Device (CCD) cameras. Each color channel of the color stripe can carry more phase information, thereby reducing the image shooting times and improving the measuring speed.

The problems that exist are that: the color crosstalk problem between the color projector and the color CCD camera, which is involved in color coding, can directly affect the phase calculation and reduce the precision of the measurement of the three-dimensional shape of the object. With the development and wide application of color grating fringe projection technology, the research on the problem of crosstalk elimination between color channels becomes more and more important. The number of the adopted projection stripes directly influences the rapidity and the real-time performance of the three-dimensional reconstruction. There are many technical problems to be solved in the practical application of the color coding stripe technology. In order to cover all spectral ranges, crosstalk and imbalance problems exist between color channels of the projection and imaging systems, so that the shape of the fringes is changed, a large phase error is generated in unwrapped absolute phases, and the three-dimensional reconstruction accuracy is finally influenced.

Disclosure of Invention

In view of the above, the present invention is directed to overcome the drawbacks of the prior art and to provide a crosstalk compensation method for a color-coded grating based on a projection plane. The method can compensate phase errors caused by crosstalk and unbalance of light intensity among R \ G \ B channels in the three-dimensional measurement process of the color coding grating, and correct phase information is obtained by avoiding phase fluctuation. The rapid measurement of the object to be measured can be met by adopting fewer projection pictures, and the precision and the efficiency in the three-dimensional reconstruction process are ensured.

The invention relates to a color coding grating crosstalk compensation method based on a projection plane, which comprises the following steps:

step 1: respectively projecting 3-frequency 3-step black and white stripe images (horizontal and vertical) and color stripe images (horizontal and vertical) on a standard flat plate, and respectively collecting the two groups of images;

step 2: performing channel separation according to the horizontal and vertical color images collected in the step 1, and separating the color deformation fringe pattern into three channels R \ G \ B to obtain 18(9+9) single-channel images;

and step 3: respectively unwrapping the two groups of images to obtain black and whiteAbsolute phase of fringes and color fringes: gray _ PHI_u、Gray_PHI_νAnd RGB _ PHI_u、RGB_PHI_ν. Each group of absolute phases can be respectively converted into a projection plane by a projection plane conversion equation to obtain projection plane coordinates of black-white stripes and color stripes: gray (u)_p,v_p) And RGB (u)_p,v_p)；

And 4, step 4: by taking the difference between the two sets of absolute phases in step 3, an error lookup table err (u) between the conventional black and white stripes and the color stripes can be established_p,v_p)；

And 5: and (3) projecting the color fringe pattern on the surface of the object to be detected according to the method flow of the step (1) and the step (2), and acquiring to obtain a color deformation fringe image. And obtaining a real object phase coordinate based on the projection plane through a unwrapping algorithm and a projection plane conversion equation: RGB _ obj (u)_p,v_p)；

Step 6: RGB (u) calculated from steps 3 and 4_p,v_p) And err (u)_p,v_p) For the phase coordinates RGB _ obj (u) of the object to be measured in step 5_p,v_p) Point-to-point crosstalk compensation is performed. For RGB _ obj (u) based on shortest distance search algorithm_p,v_p) At a certain point M (u)_p,v_p) Can be in RGB (u)_p,v_p) Searching for a point P_min(u_p,v_p) As the shortest distance coordinate, corresponds to the error lookup table err (u) in the camera coordinate system_p,v_p) Middle point N (u)_p,v_p) Is point M (u)_p,v_p) The error compensation amount of (2).

And 7: according to the error compensation quantity of the corresponding point obtained in the step 6, the object RGB _ obj (u) to be detected is subjected to the projection plane coordinate system_p,v_p) Compensating, and obtaining an absolute phase PHI through reduction of a projection plane conversion equation_hAnd PHI_ν(vertical direction PHI therein)_v) And further reconstructing the three-dimensional shape.

Furthermore, in the step 1, the coding stripe periods of the black and white stripes and the color stripes are consistent, the high, middle and low frequencies should be reasonable,the doubling frequency value is obtained as much as possible. The light intensity value of the projection grating modulated by each channel in the 3-frequency 3-step color coding stripe should satisfy: i is_R＞I_G＝I_B；

Further, in step 1, the encoding method of the color fringe pattern and the light intensity value of each channel projection are shown in the following formulas (1) to (3):

I_R(x,y)＝A_R(x,y)+B_R(x,y)cos[φ(x,y)-2π/3], (1)

I_G(x,y)＝A_G(x,y)+B_G(x,y)cos[φ(x,y)], (2)

I_B(x,y)＝A_B(x,y)+B_B(x,y)cos[φ(x,y)+2π/3]. (3)

it I_i(i ═ R \ G \ B) is the modulated light intensity values of the three channels R \ G \ B;

A_i(i ═ R \ G \ B) is the background light intensity of three channels R \ G \ B, B_i(i ═ R \ G \ B) is the modulation amplitude;

phi (x, y) is a wrapping phase value of the object to be detected;

further, the projection plane conversion equation described in step 2 can be obtained by the following equations (4) to (5):

wherein u is_pAnd v_pA line in the projection plane (DMD image) for the u and v directions, respectively;

PHI_v、PHI_habsolute phase values for vertical and horizontal directions;

N_vand N_hThe number of the stripes of the grating image;

w and H are the resolutions of the image in the horizontal and vertical directions of the projection image of the image respectively;

further, wherein in step 4 the error between black and white stripes and color stripes is looked up in a table err (u)_p,v_p) The following can be obtained from equation (6):

err(u_p,v_p)＝Gray(u_p,v_p)-RGB(u_p,v_p). (6)

wherein, Gray (u)_p,v_p) And RGB (u)_p,v_p) Absolute phase values of the black and white stripes and the color stripes under the projection plane respectively;

further, the shortest distance searching algorithm in step 6 is provided, wherein for RGB _ obj (u)_p,v_p) At a certain point M (u)_p,v_p) Can be in RGB _ (u)_p,v_p) Searching for a point P_min(u_p,v_p) As the shortest distance coordinate. P_min(u_p,v_p) Is iteratively calculated, i.e. P_i(u_p,v_p) And M (u)_p,v_p) When the difference value of (A) is minimum, finding the corresponding point as P_min(u_p,v_p)；

Further, in step 7, the object to be tested RGB _ obj (u) is processed_p,v_p) Compensating the absolute phase value RGB _ ideal (u)_p,v_p) The following can be obtained from equation (7):

RGB_ideal(u_p,v_p)＝RGB(u_p,v_p)+err(u_p,v_p). (7)

further, wherein, according to the formulas (4) and (5), RGB _ ideal (u) is restored through the projection plane conversion equation_p,v_p) The absolute phase PHI obtained thereafter_uAnd PHI_νTaking the absolute phase PHI of the vertical direction therein_v。

According to the method, after the unwrapped absolute phase is obtained, the three-dimensional morphology can be easily reconstructed. Thereby realizing the high-precision and quick measurement of the three-dimensional shape of the measured object.

The invention has the beneficial effects that: the invention discloses a color coding grating crosstalk compensation method based on a projection plane, which can obtain three-dimensional shape information of a measured object by projecting 3 color grating fringe patterns. The crosstalk compensation based on the projection plane is creatively provided, the absolute phase is converted onto the projection plane, and point-to-point and full gray value compensation is carried out. Compared with the existing color crosstalk compensation algorithm, the method only needs to establish an error lookup table, and then can compensate the full-field absolute phase value of the object to be detected to obtain the high-precision unwrapped absolute phase. In general, the present invention compensates for cross talk and imbalance problems between color channels in a fast three-dimensional measurement of digital gratings while also eliminating errors present in other black and white fringe and color fringe contouring. The method can extract multi-channel stripes from a color image, and utilizes the error lookup table of a projection plane to perform crosstalk compensation, thereby providing a feasible method for high-precision measurement of the color coding grating, being applicable to the field of rapid three-dimensional measurement and being suitable for large-scale popularization and application.

Drawings

To achieve the above advantages and other features of the present invention, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. In the drawings:

FIG. 1 is a schematic view of a measurement system of the present invention.

Fig. 2 is a schematic diagram of the cross talk compensation method of the color coding grating of the projection plane according to the present invention.

FIG. 3 is a flow chart of the crosstalk compensation method for the color-coded grating of the projection plane according to the present invention.

Detailed Description

Fig. 1 to 3 show a projection plane-based color-coded grating crosstalk compensation method according to the present invention, which is implemented by a structured light measurement system including a terminal 1, a projector 2, and an industrial camera 4, wherein the projector 2 and the industrial camera 4 are disposed in front of a measured object 3, and the projector 2 and the industrial camera 4 are both connected to the terminal 1. The terminal 1 can control the projector 2 to project a fringe grating with phase information to the measured object, and the industrial camera 4 can collect a fringe image modulated by the surface of the measured object in real time and send the fringe image to the terminal 1 for analysis and subsequent operations, such as the operation of the method.

Referring to fig. 1, the invention discloses a color coding grating crosstalk compensation method based on a projection plane, which comprises the following steps:

step 1: the surface structured light measuring system as shown in fig. 1 mainly comprises the terminal 1, the projector 2 and the industrial camera 4, wherein the projector 2 and the industrial camera 4 are arranged in front of the measured object 3, and the arrangement positions of the projectors are such that the shooting range of the industrial camera 4 covers the projection range of the projector 2. For example, in the example of fig. 1, the projector 2 and the industrial camera 4 are respectively located in front of the object to be measured, and the projector 2 and the industrial camera 4 are respectively located on both sides of the object to be measured, so that the projector 2 can project a modulated fringe image to the object to be measured 3 from one side portion in front of the object to be measured, and the industrial camera 4 can capture the fringe image projected to the object to be measured 3 from the other side portion in front of the object to be measured 3; preferably, the light intensity values of the projection grating modulated by each channel in the three-step phase-shift stripe should satisfy the following three frequencies of high, medium and low (P1-36, P2-6 and P3-1): i is_R＞I_G＝I_BAnd the phase shift stripes with the phase difference of 2 pi/3 are respectively pressed in the three channels of R \ G \ B. Black and white stripe images (horizontal and vertical) and color stripe images (horizontal and vertical) are respectively projected on a standard flat plate, and the two groups of images are respectively acquired. The encoding method of the color fringe pattern and the light intensity value projected by each channel are shown in the following formulas (1) to (3):

I_R(x,y)＝A_R(x,y)+B_R(x,y)cos[φ(x,y)-2π/3], (1)

I_G(x,y)＝A_G(x,y)+B_G(x,y)cos[φ(x,y)], (2)

I_B(x,y)＝A_B(x,y)+B_B(x,y)cos[φ(x,y)+2π/3]. (3)

it I_i(i ═ R \ G \ B) is the modulated light intensity values of the three channels R \ G \ B;

A_i(i ═ R \ G \ B) is the background light intensity of three channels R \ G \ B, B_i(i ═ R \ G \ B) is the modulation amplitude;

phi (x, y) is a wrapping phase value of the object to be detected;

step 2: channel separation is carried out through an image collected by the terminal 1, and horizontal and vertical color deformation fringe groups are respectively separated into three R \ G \ B channels to obtain 18(9+9) single-channel images;

and step 3: and respectively unwrapping the phases of the two groups of images to obtain the absolute phases of the black-white stripes and the color stripes: gray _ PHI_u、Gray_PHI_νAnd RGB _ PHI_u、RGB_PHI_ν. Each group of absolute phases can be respectively converted into a projection plane by a projection plane conversion equation to obtain projection plane coordinates of black-white stripes and color stripes: gray (u)_p,v_p) And RGB (u)_p,v_p) The projection plane conversion equation can be obtained by the following equations (4) to (5):

wherein u is_pAnd v_pA line in the projection plane (DMD image) for the u and v directions, respectively;

PHI_v、PHI_habsolute phase values for vertical and horizontal directions;

N_vand N_hThe number of the stripes of the grating image;

w and H are the resolutions of the image in the horizontal and vertical directions of the projection image of the image respectively;

and 4, step 4: by taking the difference between the two sets of absolute phases in step 3, an error lookup table err (u) between the conventional black and white stripes and the color stripes can be established_p,v_p) The following equation (6) can be used to obtain:

err(u_p,v_p)＝Gray(u_p,v_p)-RGB(u_p,v_p). (6)

wherein, Gray (u)_p,v_p) And RGB (u)_p,v_p) Absolute phase values of the black and white stripes and the color stripes under the projection plane respectively;

and 5: and projecting the projection color fringe pattern to the surface of a measured object 3 through a projector 2, and acquiring an image through an industrial camera 4 to obtain color deformation fringe images in the horizontal direction and the vertical direction. And obtaining a real object phase coordinate based on the projection plane through a unwrapping algorithm and a projection plane conversion equation: RGB _ obj (u)_p,v_p)；

Step 6: RGB (u) calculated from steps 3 and 4_p,v_p) And err (u)_p,v_p) For the phase coordinates RGB _ obj (u) of the object to be measured in step 5_p,v_p) Point-to-point crosstalk compensation is performed. For RGB _ obj (u) based on shortest distance search algorithm_p,v_p) At a certain point M (u)_p,v_p) Can be in RGB (u)_p,v_p) Searching for a point P_min(u_p,v_p) As the shortest distance coordinate, corresponds to the error lookup table err (u) in the camera coordinate system_p,v_p) Middle point N (u)_p,v_p) Is point M (u)_p,v_p) The error compensation amount of (2).

Wherein the object to be tested RGB _ obj (u)_p,v_p) Compensating the absolute phase value RGB _ ideal (u)_p,v_p) The following can be obtained from equation (7):

RGB_ideal(u_p,v_p)＝RGB(u_p,v_p)+err(u_p,v_p). (7)

and 7: obtaining the compensated absolute phase value RGB _ ideal (u) according to the step 6_p,v_p) The absolute phase PHI is obtained by reduction of the projection plane transformation equation_hAnd PHI_ν(vertical direction PHI therein)_v) And further reconstructing the three-dimensional shape.

According to the method, after the unwrapped absolute phase is obtained, the three-dimensional morphology can be easily reconstructed. Thereby realizing the high-precision and quick measurement of the three-dimensional shape of the measured object.

In general, in the surface structured light three-dimensional measurement system, the three-dimensional shape information of the measured object can be obtained by projecting 3 color grating fringe patterns by utilizing the advantage of the multi-channel property of the color composite grating. The crosstalk compensation based on the projection plane is creatively provided, the absolute phase is converted onto the projection plane, and point-to-point and full gray value compensation is carried out. Compared with the existing color crosstalk compensation algorithm, the method only needs to establish an error lookup table, and then can compensate the full-field absolute phase value of the object to be detected to obtain the high-precision unwrapped absolute phase. In general, the invention compensates the crosstalk and unbalance problem among the color channels in the three-dimensional measurement of the color coding grating, and simultaneously eliminates the errors existing in other black and white stripe and color stripe profilometry to obtain accurate phase information.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.