CN113160393B - High-precision three-dimensional reconstruction method and device based on large depth of field and related components thereof - Google Patents

Abstract

The invention discloses a high-precision three-dimensional reconstruction method and device based on a large depth of field and related components thereof. The method comprises the following steps: dividing the area of the large depth of field measurement scene; performing binocular vision three-dimensional calibration on each divided region by using a three-dimensional measurement system to obtain calibration data; calculating absolute phase distribution diagrams and three-dimensional information of the planar plate at different positions; establishing a three-dimensional mapping coefficient table of the corresponding region; acquiring a target image of a measured object and calculating an absolute phase distribution map; and acquiring the absolute phase of an absolute phase distribution diagram of each pixel point in the target image, searching a three-dimensional mapping coefficient in a three-dimensional mapping coefficient table of the corresponding region, and calculating the space three-dimensional point coordinates by using the three-dimensional mapping coefficient. According to the method, the large depth of field scene is divided into a plurality of areas for calculation, the whole calculation process is more rigorous and accurate, and the space three-dimensional point coordinates of the measured object are obtained after the three-dimensional mapping coefficient table is built.

Description

High-precision three-dimensional reconstruction method, device and related components based on large depth of field

technical field

The present invention relates to the technical field of three-dimensional imaging, in particular to a high-precision three-dimensional reconstruction method, device and related components based on a large depth of field.

Background technique

The fringe projection 3D measurement in the prior art is a kind of structured lighting method, which has the advantages of high speed, high precision, low cost, and easy operation, and has been widely used in industrial measurement, intelligent manufacturing, cultural relics protection and other fields. The principle of the fringe projection three-dimensional measurement technology is to project the standard sinusoidal fringe pattern on the measured object. The height of the object modulates the projected fringe. -Height mapping principle to reconstruct the three-dimensional information of the object.

Typically, fringe projection uses a digital micromirror array (DMD) based on the principle of optical imaging to generate fringe patterns, and an optical projection lens with a fixed focal length has a limited depth of field range. Especially in order to improve the brightness of the image, commercial projectors adopt a large aperture design, resulting in a smaller depth of field. In some large measurement scenarios, the object to be measured has a large volume or a large span space composed of multiple objects, and the projection system cannot meet the demand. The MEMS (micro-electromechanical system) galvanometer laser scanning projector has an imaging range with a large depth of field due to the use of a laser light source and a projection method of galvanometer scanning. Camera lenses also face the problem of limited depth of field, while electronic zoom lenses have the function of continuously changing the focal length of the lens.

In recent years, the development of Electrically Tunable Lens (ETL) has provided more options for designing more compact optical systems, especially its precision, speed, convenience and repeatability, etc., which have been widely used in Display, microscopy, autofocus imaging, laser processing and other fields. For three-dimensional measurement, there are also studies using electronically adjustable lenses to achieve certain functions. One technique is to rapidly acquire multiple discrete focused images using an electronically tunable lens, and to obtain 3D information of the entire scene by combining data from different focusing situations. However, the current 3D measurement system has low accuracy when measuring scenes with a large depth of field, and the problems of poor reconstruction and recovery effects still cannot be solved.

Contents of the invention

Embodiments of the present invention provide a high-precision 3D reconstruction method, device and related components based on a large depth of field, aiming at solving the problems of low 3D measurement accuracy and poor 3D reconstruction effect in a scene with a large depth of field in the prior art.

In the first aspect, an embodiment of the present invention provides a high-precision three-dimensional reconstruction method based on a large depth of field, including:

Regional division of large depth of field measurement scenes;

Using a three-dimensional measurement system to carry out binocular vision stereo calibration for each divided area to obtain calibration data; wherein the three-dimensional measurement system includes an imaging device and a projection device;

Use the projection device to project specified patterns to the flat panel at different positions in different areas, and collect the flat panel images of the flat panel at different positions through the imaging device, and calculate the absolute phase distribution of the flat panel at different positions , and calculate the three-dimensional information of the plane plate at different positions according to the calibration data;

In each area, the absolute phase of each pixel of the imaging device in the absolute phase distribution map of the flat plate is obtained, and according to the relationship between the three-dimensional information of each flat plate and the absolute phase of the corresponding pixel The mapping relation establishes the three-dimensional mapping coefficient table of the corresponding area;

Use the projection device to project the target pattern to the measured object, collect the target focal scan image of the measured object through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image and calculate the absolute phase of the target image Distribution;

Obtain the absolute phase of each pixel of the target image in the absolute phase distribution map of the target image, and search for the corresponding three-dimensional mapping coefficient in the three-dimensional mapping coefficient table of the corresponding area according to the area to which the absolute phase belongs, using the The three-dimensional mapping coefficients are calculated to obtain the corresponding three-dimensional point coordinates in space.

In the second aspect, an embodiment of the present invention provides a high-precision three-dimensional reconstruction device based on a large depth of field, which includes:

The area division unit is used to perform area division on the large depth of field measurement scene;

The calibration data acquisition unit is used to use the three-dimensional measurement system to perform binocular vision stereo calibration on each divided area to obtain calibration data; wherein the three-dimensional measurement system includes an imaging device and a projection device;

The three-dimensional information acquisition unit is used to project a specified pattern to the flat panel at different positions by using the projection device in different areas, and collect the flat panel images of the flat flat panel at different positions through the imaging device, and calculate the position of the flat flat panel at Absolute phase distribution diagrams at different positions, and calculate the three-dimensional information of the flat plate at different positions according to the calibration data;

A three-dimensional mapping coefficient table acquisition unit, configured to acquire the absolute phase of each pixel of the imaging device in the absolute phase distribution diagram of the flat plate in each area, and obtain the absolute phase according to the three-dimensional information of each of the flat plates Establish a three-dimensional mapping coefficient table for the corresponding area with the mapping relationship between the absolute phase of the corresponding pixel point;

The target focal scan image acquisition unit is used to project the target pattern to the object under test by using the projection device, collect the target focal scan image of the object under test through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image and calculating the absolute phase distribution map of the target image;

A spatial three-dimensional point coordinate acquisition unit, configured to acquire the absolute phase of each pixel point of the target image in the absolute phase distribution map of the target image, and search in the three-dimensional mapping coefficient table of the corresponding area according to the area to which the absolute phase belongs The corresponding three-dimensional mapping coefficients are used to calculate corresponding three-dimensional point coordinates in space.

In a third aspect, the embodiment of the present invention provides a computer device, which includes a memory, a processor, and a computer program stored on the memory and operable on the processor, and the processor executes the computer program. The program implements the high-precision three-dimensional reconstruction method based on the large depth of field described in the first aspect above.

In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor executes the above-mentioned first step. In one aspect, the high-precision three-dimensional reconstruction method based on a large depth of field.

Embodiments of the present invention provide a high-precision three-dimensional reconstruction method, device and related components based on a large depth of field. The method includes: dividing the large depth of field measurement scene into regions; using a three-dimensional measurement system to perform binocular vision stereo calibration on each divided region to obtain calibration data; wherein, the three-dimensional measurement system includes an imaging device and a projection device; In different areas, the projection device is used to project a specified pattern to the flat plate at different positions, and the flat plate images at different positions are collected by the imaging device, and the absolute phase distribution diagram of the flat plate at different positions is calculated , and calculate the three-dimensional information of the flat panel at different positions according to the calibration data; in each region, obtain the absolute phase of each pixel of the imaging device in the absolute phase distribution diagram of the flat panel , and according to the mapping relationship between the three-dimensional information of each of the flat plates and the absolute phase of the corresponding pixel point, a three-dimensional mapping coefficient table of the corresponding area is established; the target pattern is projected to the measured object by the projection device, and the image is collected by the imaging device Measure the target focal scan image of the object, and perform deblurring processing on the target focal scan image to obtain the target image and calculate the absolute phase distribution map of the target image; obtain each pixel of the target image in the target image According to the absolute phase of the absolute phase distribution map, and according to the area to which the absolute phase belongs, look up the corresponding three-dimensional mapping coefficient in the three-dimensional mapping coefficient table of the corresponding area, and use the three-dimensional mapping coefficient to calculate the corresponding three-dimensional point coordinates in space. The embodiment of the present invention divides the scene with large depth of field into regions, and establishes a three-dimensional mapping coefficient table for each region, and directly obtains the three-dimensional mapping coefficients of the corresponding region of the measured object during three-dimensional reconstruction, thereby calculating the spatial three-dimensional point coordinates, through Divide the scene with large depth of field into multiple areas for calculation, the whole calculation process is more rigorous and accurate, and it is more rapid and accurate to obtain the spatial three-dimensional point coordinates of the measured object after the three-dimensional mapping coefficient table is established.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. Ordinary technicians can also obtain other drawings based on these drawings on the premise of not paying creative work.

FIG. 1 is a schematic flowchart of a high-precision three-dimensional reconstruction method based on a large depth of field provided by an embodiment of the present invention;

FIG. 2 is a simulation diagram of a high-precision three-dimensional reconstruction method based on a large depth of field provided by an embodiment of the present invention;

Fig. 3 is a schematic block diagram of a high-precision three-dimensional reconstruction device based on a large depth of field provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be understood that when used in this specification and the appended claims, the terms "comprising" and "comprises" indicate the presence of described features, integers, steps, operations, elements and/or components, but do not exclude one or Presence or addition of multiple other features, integers, steps, operations, elements, components and/or collections thereof.

It should also be understood that the terminology used in the description of the present invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used in this specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural referents unless the context clearly dictates otherwise.

It should also be further understood that the term "and/or" used in the description of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations .

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic flowchart of a high-precision three-dimensional reconstruction method based on a large depth of field provided by an embodiment of the present invention. The method includes steps S101-S106.

S101. Divide the large depth of field measurement scene into regions;

In this step, since the scene with a large depth of field is relatively large, if the scene with a large depth of field is directly measured during 3D reconstruction, the accuracy will decrease. The measurement space is divided to obtain several smaller measurement areas.

In one embodiment, after the step S101, including

Using a calibration algorithm to calibrate the positions of the imaging device and the projection device;

Obtaining the maximum and minimum values of the total control current measured by the zoom lens of the imaging device in the large depth of field measurement scene, and the corresponding area control current value when the zoom lens of the imaging device focuses on the center position of each area, and Record the maximum and minimum values of the total control current and the regional control current value corresponding to each region.

In this step, firstly, the positions of the imaging device and the projection device are calibrated, and then according to the measurement depth range when the imaging device is in focus and the diopter variation range of the zoom lens of the imaging device, the location of the measurement scene is determined. Appropriate depth range, by changing the diopter of the zoom lens, so that the zoom lens can focus on the center position of different areas, and then record the corresponding control current value when the zoom lens focuses on the center position of different areas, adjust The diopter of the zoom lens enables the imaging device to respectively focus on the maximum depth and the minimum depth of the large depth of field measurement scene, and record the control current value corresponding to the depth. In this embodiment, the minimum depth of the large depth of field measurement scene is 400mm, and the maximum depth is 1000mm.

S102. Use a three-dimensional measurement system to perform binocular vision stereo calibration on each divided area to obtain calibration data; wherein, the three-dimensional measurement system includes an imaging device and a projection device;

In this step, a three-dimensional measurement system is composed of an imaging device with a zoom lens and a projection device with a MEMS vibrating mirror, and the binocular vision stereoscopic calibration is performed on each area by the three-dimensional measurement system to obtain calibration data. The imaging device may be a zoom camera with a zoom lens, and the projection device may be a projector with a MEMS vibrating mirror.

In one embodiment, the use of a three-dimensional measurement system to carry out binocular vision stereo calibration for each divided area to obtain calibration data includes:

Taking the optical center of the imaging device as the origin, and taking the optical axis of the imaging device as the Z axis, an imaging device coordinate system is established; taking the optical center of the projection device as the origin, and taking the optical axis of the projection device For the Z axis, establish the coordinate system of the projection device;

Obtain the conversion relationship between the intrinsic parameters of the imaging device and the coordinate system of the imaging device and the conversion relationship between the intrinsic parameters of the projection device and the projection coordinate system by using the binocular vision stereo calibration algorithm, and calculate the coordinates of the imaging device coordinate system and projected coordinate system to obtain calibration data.

In this embodiment, the intrinsic parameters of the imaging device and the projection device are obtained. The intrinsic parameters of the imaging device and the projection device are the intrinsic parameter matrix, including focal length, optical center position, and number of pixels per unit distance. There is a corresponding conversion relationship between the intrinsic parameters of the imaging device and the coordinate system of the imaging device, and a corresponding conversion relationship between the intrinsic parameters of the projection device and the coordinate system of the projection device, and the calculation of the The conversion relationship between the coordinate system of the imaging device and the projected coordinate system.

Wherein, the calibration process of the imaging device is as follows:

Assuming that there is a point P in a certain area, its coordinates in the world coordinate system and the imaging device coordinate system are (X _W , Y _W , Z _W ) and (X _c , Y _c , Z _c ), respectively. The projection coordinates on the imaging plane of are (u,v), then the perspective projection imaging process is: Among them, s _x , s _y are the number of pixels per unit distance of the image plane along the corresponding image coordinate axis (pixel/mm); (u ₀ , v ₀ ) is the intersection point of the optical axis of the imaging device and the image plane, that is, the optical center The projection on the image plane is called the principal point; f _x , f _y are the equivalent focal lengths along the corresponding image coordinate axes; R is a 3×3 orthogonal matrix, T is a 3×1 vector, R and T denote the rotation and translation transformations from the world coordinate system to the imaging device coordinate system, respectively. The above formula can be abbreviated as: /> Among them, s is the scale factor; [RT] is the external parameter matrix; /> and /> Respectively, the homogeneous coordinates of the three-dimensional point P in space and its image point; M is the projection matrix; K is the internal parameter matrix: /> The conversion relationship from the world coordinate system to the imaging device coordinate system is: /> Due to the deviation of the imaging device during the imaging process, it is necessary to calculate the radial distortion and tangential distortion, which are expressed as: δ _Rx = x(k ₁ r ² +k ₂ r ⁴ + k ₃ r ⁶ ), δ _Ry ＝y(k ₁ r ² +k ₂ r ⁴ +k ₃ r ⁶ ), δ _Tx ＝2p ₁ xy+p ₂ (r ² +2x ² ), δ _Ty ＝p ₁ ( r ² +2y ² )+2p ₂ xy. Among them, δ _Rx and δ _Ry are the radial distortions in the x direction and y direction, respectively; δ _Tx and δ _Ty are the tangential distortions in the x direction and y direction, respectively; (x, y) are ideal image coordinates; Indicates the distance from the ideal image point to the principal point; k ₁ , k ₂ and k ₃ are radial distortion parameters; p ₁ and p ₂ are tangential distortion parameters. After considering these two kinds of distortion errors, the process of converting an ideal image point (x, y) into a distorted image point (x', y') can be expressed as: x'=x+δ _Rx +δ _Tx , y'=y +δ _Ry +δ _Ty .

For each area, the three-dimensional measurement system is used to collect target images of the planar target at different positions, and the position of the imaging device is calculated using the Zhang Zhengyou calibration algorithm based on the target images. When collecting target images, first place the planar target in the middle of a certain area, use the imaging device to collect the target image, change the planar target to another position, and continue to collect the target image, and multiple sets of target images are obtained by performing multiple position transformations on the planar target. The overall process of the Zhang Zhengyou calibration algorithm is as follows: firstly, the imaging device is used to capture multiple target images of the planar target at different positions, and then the target images are detected to obtain the feature points of the target images , and then solve the internal parameters and external parameters of the imaging device under the ideal non-distortion situation and use the maximum likelihood estimation to improve the accuracy, and apply the least squares to find the actual radial distortion coefficient of the imaging device, according to the imaging device Internal parameters, external parameters, and radial distortion coefficients are estimated using the maximum likelihood method to optimize estimation and improve estimation accuracy.

The calibration process of the projection device is as follows:

During the calibration process of the projection device, the phase shift technique is used to obtain the corresponding relationship between the image of the imaging device and the image of the projection device. The projection device projects a group of phase shift images and Gray code code images of horizontal stripes on the plane target, and the imaging device collects target images. Then, the absolute phase value Ф _h of the horizontal direction of the plane target circle center (u _C , v _C ) is calculated by using the phase shift plus Gray code solution, and a horizontal corresponding line of the image of the projection device is found through the absolute phase value, and its coordinate value v _P is : Among them, N _h is the total number of stripes of the horizontal phase shift pattern; H is the vertical resolution of the projection device image. In the same way, the projection device projects a set of phase displacement maps and Gray code code maps of vertical stripes, and the absolute phase value Ф _v in the vertical direction of the center (u _C , v _C ) of the same calibration point can be obtained, which is shown on the image of the projection device The corresponding coordinate value u _P is: Wherein, N _v is the total number of stripes of the vertical phase shift pattern; W is the horizontal resolution of the image of the projection device. The method of calibrating the parameters of the projection device is the same as that of the imaging device, and the calibration of the projection device is to obtain the internal parameter matrix of the projection device.

For each area, after the imaging device is calibrated, the projection device is calibrated. Use the projection device to project a pattern on the planar target, and the imaging device collects the target image of the planar target with the pattern, then changes the position of the planar target to continue projecting the pattern and collect the target image, after several times Changing the position of the planar target to obtain multiple groups of target images, and then calculating the orthogonal absolute phase distribution map of each target image by using the obtained target images. Specifically, the gray code combined with the phase shift method can be used for phase decoding, so as to calculate the orthogonal absolute phase distribution diagram of each target image. The gray code plus phase shift method can not only reduce the number of coding bits of the Gray code, speed up the decoding speed, but also make up for the shortcomings of the simple phase shift method and the Gray code method that are difficult to reconstruct discontinuous positions. The specific encoding method of combining Gray code and phase shift method is as follows: first project a series of Gray code black and white stripe patterns to the measured object, and the area with the same code is regarded as a code cycle, and then use the phase shift method to project the phase shift in turn pattern such that each coding region is further subdivided consecutively. Through the orthogonal absolute phase distribution diagram of the target image, a pair of points with the same name on the image plane of the imaging device and the image plane of the projection device are found, that is, the image point on the image plane of the imaging device is the point to be matched, and the image point on the image plane of the projection device is used as the point to be matched. Find the first sub-pixel point on the surface that has the same absolute phase as the point to be matched. Finally, the position of the projection device is calculated by using the Zhang Zhengyou calibration algorithm according to the target image.

S103. Use the projection device to project a specified pattern to the flat panel at different positions in different areas, and collect the flat panel images of the flat flat at different positions through the imaging device, and calculate the absolute value of the flat flat at different positions. phase distribution diagram, and calculate the three-dimensional information of the plane plate at different positions according to the calibration data;

In this step, in each area, use the projection device with the MEMS galvanometer to project a specified pattern to the flat panel at different positions, and collect the image of the flat panel through the imaging device, and then calculate according to the flat panel image The absolute phase distribution diagram of the flat plate at different positions, and the three-dimensional information of the flat plate is calculated by using the pre-acquired calibration data. The calibration data includes: the intrinsic parameters of the imaging device and the projection device, the distortion coefficient of the zoom lens of the imaging device and the conversion relationship between the two coordinate systems.

The specific acquisition process of the flat panel image of the flat flat panel is: the flat flat panel is placed in the measurement area, the projection device projects the orthogonal sinusoidal phase shift fringe pattern and the Gray code code pattern on the flat flat panel, and the imaging device takes pictures and collects The flat panel images at different positions, and then change the position of the flat flat panel, repeat the process of projection and acquisition, and obtain multiple sets of flat panel image data.

In one embodiment, the calculation according to the calibration data to obtain the three-dimensional information of the flat panel at different positions includes:

The three-dimensional information is calculated according to the following formula:

s _C [u _C ,v _C ,1] ^T ＝K _C M _C [X _W ,Y _W ,Z _W ,1] ^T

s _P [u _P ,v _P ,1] ^T ＝K _P I[X _W ,Y _W ,Z _W ,1] ^T

Among them, s _C and s _P are the scale factors of the imaging device and the projection device, respectively, K _C and K _P are the internal parameter matrices of the imaging device and the projection device, respectively, M _C is the external parameter matrix of the imaging device, I is the identity matrix, (u _C , v _C ) and (u _P , v _P ) are the image coordinates of the imaging device and the projection device after the distortion parameters of the three-dimensional measurement system are corrected, and T is the transpose of the matrix.

In this embodiment, the three-dimensional reconstruction process of the P point by the three-dimensional measurement system can be expressed as: Among them, s _C and s _P are the scale factors of the imaging device and the projection device, respectively, K _C and K _P are the internal parameter matrices of the imaging device and the projection device, respectively, and M _C and _MP are the external parameters of the imaging device and the projection device, respectively. matrix. The structural parameters of the three-dimensional measurement system can be expressed as: /> Among them, r is the rotation vector from the coordinate system of the projection device to the coordinate system of the imaging device, and t is the translation vector from the coordinate system of the projection device to the coordinate system of the imaging device; if the world coordinate system is established in the coordinate system of the projection device, then R _P is the unit matrix, T _P is the zero matrix, R _C is the rotation vector from the world coordinate system to the imaging device coordinate system, T _C is the translation vector from the world coordinate system to the imaging device coordinate system, M _P =I, and the three-dimensional reconstruction process is transformed into :/> Wherein, I is the identity matrix; (u _C , v _C ) and (u _P , v _P ) are the image coordinates of the imaging device and the projection device after the system distortion parameters are corrected. After calculating the three-dimensional coordinates (X _W , Y _W , Z _W ) of point P, combined with the absolute phase value Ф ₁ of point P, the sampling data of the phase three-dimensional mapping coefficient table of a pixel point of an imaging device in an area is obtained.

S104. In each area, obtain the absolute phase of each pixel of the imaging device in the absolute phase distribution diagram of the flat plate, and according to the three-dimensional information of each flat plate and the absolute phase of the corresponding pixel The mapping relationship between establishes a three-dimensional mapping coefficient table for the corresponding area;

In this step, the absolute phase corresponding to each pixel of the imaging device in different areas is obtained according to the pre-calculated absolute phase distribution diagram of the flat plate, and then the relationship between each pixel and the corresponding three-dimensional information is obtained The mapping relationship among them, so as to establish the three-dimensional mapping coefficient table of the corresponding area. In each area, a position information of the flat plate is used as a set of sampling data, that is, a pixel corresponds to a three-dimensional space point and a phase value. The plane plates at multiple positions provide multiple sets of sampling data, and by fitting the mapping coefficients, a mapping coefficient table for each pixel in an area is obtained.

In one embodiment, the step S104 includes:

According to the three-dimensional information corresponding to the pixel point, the three-dimensional mapping coefficient is calculated according to the following formula, and the three-dimensional mapping coefficient table is established:

Among them, α _n , c _X , b _n , c _Y , c _n and c _Z are three-dimensional mapping coefficients, N is the polynomial order, and Ф is the absolute phase of the corresponding pixel.

In this embodiment, given that the absolute phase of a pixel point m _c is Ф _C , and its three-dimensional space point is (X, Y, Z), according to the three-dimensional information of the pixel point, it can be deduced as follows: Among them, α _n , c _X , b _n , c _Y , c _n and c _Z correspond to the mapping coefficients of the three spatial dimensions. The mapping coefficient {a _n , b _n , c _n } corresponding to each pixel can be calculated through the above formula, so as to establish a three-dimensional mapping coefficient table corresponding to the absolute phase of each pixel in each region.

S105. Use the projection device to project the target pattern to the object under test, collect the target focal scan image of the target object through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image and calculate the target image Absolute phase profile;

In this step, a projection device with a MEMS galvanometer is used to project a pattern to the measured object, and the imaging device collects the target focal scan image of the measured object under a single-frame exposure condition, and then the target focal scan image Deblurring processing is performed to obtain a target image, and then an absolute phase distribution map of the target image is calculated. The imaging device continuously scans the focal plane under the single-frame exposure condition to obtain the target focal-scan image, and the single-frame exposure time is the size of the current period for controlling the zoom lens of the imaging device. The current cycle changes with time in a triangular wave, and the maximum and minimum values of the triangular wave are the maximum and minimum values of the current value range for controlling the imaging device to continuously focus on the entire large depth of field measurement scene. By controlling the current value of the imaging device, the exposure time of a single frame for the imaging device to collect the target focal scan image is controlled.

When collecting the target focal scan pattern of each measured object, the cycle of the control current of the zoom lens is T, the maximum value is I _H , and the minimum value is the triangular wave current of _IL , and the function of the current change with time t is: : Among them, n is a natural number.

In one embodiment, the step S105 includes:

Inputting the focal scan image of the target into an integral point spread function to perform a deconvolution operation to obtain a deblurred target image;

The calculation formula of the integral point spread function is as follows:

Among them, r is the distance from the center of the circle of confusion where the object point is imaged on the sensor plane of the imaging device; b ₀ is the diameter of the circle of confusion that the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at 0 time; b ₁ is the spot diameter of the object point focused on the sensor plane of the imaging device; _b2 is the diameter of the circle of confusion when the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at half a cycle T; C ₁ and C ₂ for two constants.

In this embodiment, an integral point spread function is constructed based on the focal scan model of the imaging device, and the deconvolution operation is performed on the target focal scan image by using the integral point spread function to obtain the deblurred target focal scan image. The calculation formula of the integral point spread function is as above, and the calculation result is deblurred by Wiener filtering.

S106. Obtain the absolute phase of each pixel of the target image in the absolute phase distribution map of the target image, and search for the corresponding three-dimensional mapping coefficient in the three-dimensional mapping coefficient table of the corresponding area according to the area to which the absolute phase belongs, and use The three-dimensional mapping coefficients are calculated to obtain corresponding three-dimensional point coordinates in space.

In this step, first, according to the absolute phase distribution diagram of the target focal scan image, the area to which each pixel point corresponding to the target focal scan image belongs is judged, and then the corresponding area is found in the three-dimensional mapping coefficient table of the corresponding area. The three-dimensional mapping coefficients are used to calculate the corresponding three-dimensional point coordinates in space.

In one embodiment, the step S106 includes:

The coordinates of the three-dimensional point in the space are calculated by the following formula:

Among them, {a _n , b _n , c _n } are the three-dimensional mapping coefficients of the corresponding area, Ф is the absolute phase of the pixel, and N is the polynomial order.

In this embodiment, the absolute phase of each pixel of the imaging device in the target focal scan image is acquired as the target phase, the area to which the target phase belongs is judged, and the corresponding area is found according to the three-dimensional mapping coefficient table of the corresponding area. The three-dimensional mapping coefficients {a _n , b _n , c _n } are calculated according to the absolute phase and the three-dimensional mapping coefficients to obtain the spatial three-dimensional point coordinates.

As shown in Figure 2, if the absolute phase of a certain pixel is Ф, the phase value range of this pixel in area 1 is Ф ¹ ₁ ～Ф ¹ _n , and the phase value range in area 2 is Ф ² ₁ ～Ф ² _n , the phase value range in region 3 is Ф ³ ₁ ∼Ф ³ _n , and the phase value range in region n is Ф ⁿ ₁ ∼Ф ⁿ _n . Determine the area to which the absolute phase belongs, if Φ ² ₁ ≤ Φ ≤ Φ ² _n , then the phase value of the pixel point belongs to area 2, and find out the three-dimensional mapping coefficient corresponding to the pixel point in the three-dimensional mapping coefficient table of area 2, Calculate the corresponding three-dimensional point coordinates in space according to the following formula: Among them, {a _n , b _n , c _n } are the three-dimensional mapping coefficients corresponding to area 2.

If Φ ² ₁ ≤Φ≤Φ ² _n and Φ ¹ ₁ ≤Φ≤Φ ¹ _n , the conditions to determine which area Φ belongs to are: When L≥0, the phase value of this image point belongs to area 1; when L<0, the phase value of this image point belongs to area 2.

Please refer to FIG. 3. FIG. 3 is a schematic block diagram of a high-precision three-dimensional reconstruction device based on a large depth of field provided by an embodiment of the present invention. The high-precision three-dimensional reconstruction device 200 based on a large depth of field includes:

The area division unit 201 is used to perform area division on the large depth of field measurement scene;

The calibration data acquisition unit 202 is configured to use a three-dimensional measurement system to perform binocular vision stereo calibration on each divided area to obtain calibration data; wherein the three-dimensional measurement system includes an imaging device and a projection device;

The three-dimensional information acquiring unit 203 is configured to use a projection device to project a specified pattern on the flat panel at different positions in different areas, and collect the flat panel images of the flat flat panel at different positions through the imaging device, and calculate the flat flat panel Absolute phase distribution diagrams at different positions, and calculate the three-dimensional information of the flat plate at different positions according to the calibration data;

The three-dimensional mapping coefficient table obtaining unit 204 is configured to obtain the absolute phase of each pixel of the imaging device in the absolute phase distribution map of the flat plate in each region, and according to the three-dimensional The mapping relationship between the information and the absolute phase of the corresponding pixel establishes a three-dimensional mapping coefficient table for the corresponding area;

The target focal scan image acquisition unit 205 is configured to use the projection device to project the target pattern to the object under test, collect the target focal scan image of the measured object through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image. image and calculate an absolute phase profile of the target image;

A spatial three-dimensional point coordinate acquisition unit 206, configured to acquire the absolute phase of each pixel point of the target image in the absolute phase distribution map of the target image, and according to the area to which the absolute phase belongs in the three-dimensional mapping coefficient table of the corresponding area The corresponding three-dimensional mapping coefficients are searched, and the corresponding three-dimensional point coordinates in space are calculated by using the three-dimensional mapping coefficients.

In an embodiment, after the region division unit 201 includes:

a position calibration unit, configured to calibrate the positions of the imaging device and the projection device using a calibration algorithm;

The control current value recording unit is used to obtain the maximum and minimum values of the total control current measured by the zoom lens of the imaging device in the scene of large depth of field measurement, and when the zoom lens of the imaging device is focused on the center position of each area The corresponding regional control current value, and record the maximum and minimum values of the total control current and the regional control current value corresponding to each region.

In an embodiment, the calibration data acquisition unit 202 includes:

A coordinate system establishing unit, configured to use the optical center of the imaging device as the origin, and the optical axis of the imaging device as the Z axis, to establish the coordinate system of the imaging device; take the optical center of the projection device as the origin, and The optical axis of the projection device is the Z axis, and the coordinate system of the projection device is established;

The calibration data calculation unit is used to obtain the conversion relationship between the intrinsic parameters of the imaging device and the coordinate system of the imaging device and the conversion relationship between the intrinsic parameters of the projection device and the projection coordinate system by using a binocular vision stereo calibration algorithm, And calculate the conversion relationship between the coordinate system of the imaging device and the projected coordinate system to obtain calibration data.

In an embodiment, the three-dimensional information acquisition unit 203 includes:

The three-dimensional information formula calculation unit is used to calculate the three-dimensional information according to the following formula:

s _C [u _C ,v _C ,1] ^T ＝K _C M _C [X _W ,Y _W ,Z _W ,1] ^T

s _P [u _P ,v _P ,1] ^T ＝K _P I[X _W ,Y _W ,Z _W ,1] ^T

Among them, s _C and s _P are the scale factors of the imaging device and the projection device, respectively, K _C and K _P are the internal parameter matrices of the imaging device and the projection device, respectively, M _C is the external parameter matrix of the imaging device, I is the identity matrix, (u _C , v _C ) and (u _P , v _P ) are the image coordinates of the imaging device and the projection device after the distortion parameters of the three-dimensional measurement system are corrected, and T is the transpose of the matrix.

In one embodiment, the three-dimensional mapping coefficient table acquisition unit 204 includes:

The three-dimensional mapping coefficient calculation unit is used to calculate the three-dimensional mapping coefficient according to the following formula according to the three-dimensional information corresponding to the pixel point, and establish a three-dimensional mapping coefficient table:

Among them, α _n , c _X , b _n , c _Y , c _n and c _Z are three-dimensional mapping coefficients, N is the polynomial order, and Ф is the absolute phase of the corresponding pixel.

In one embodiment, the target focal scan image acquisition unit 205 includes:

A deblurring processing unit, configured to input the target focal scan image to an integral point spread function for deconvolution operation, to obtain a deblurred target image;

An integral point spread function calculation unit, the calculation formula for the integral point spread function is as follows:

Among them, r is the distance from the center of the circle of confusion where the object point is imaged on the sensor plane of the imaging device; b ₀ is the diameter of the circle of confusion that the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at 0 time; b ₁ is the spot diameter of the object point focused on the sensor plane of the imaging device; _b2 is the diameter of the circle of confusion when the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at half a cycle T; C ₁ and C ₂ for two constants.

In one embodiment, the spatial three-dimensional point coordinate acquisition unit 206 includes:

A three-dimensional point coordinate calculation unit in space, configured to calculate the three-dimensional point coordinates in space by the following formula:

Among them, {a _n , b _n , c _n } are the three-dimensional mapping coefficients of the corresponding area, Ф is the absolute phase of the pixel, and N is the polynomial order.

An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory and operable on the processor. When the processor executes the computer program, the above-mentioned High-precision 3D reconstruction method based on large depth of field.

An embodiment of the present invention also provides a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the above-mentioned high-precision three-dimensional reconstruction method based on a large depth of field is implemented .

Each embodiment in the description is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for relevant details, please refer to the description of the method part. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

It should also be noted that in this specification, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations There is no such actual relationship or order between the operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Claims (9)

1. A high-precision three-dimensional reconstruction method based on large depth of field, is characterized in that, comprises the following steps: Regional division of large depth of field measurement scenes; Using a three-dimensional measurement system to carry out binocular vision stereo calibration for each divided area to obtain calibration data; wherein the three-dimensional measurement system includes an imaging device and a projection device; Use the projection device to project specified patterns to the flat panel at different positions in different areas, and collect the flat panel images of the flat panel at different positions through the imaging device, and calculate the absolute phase distribution of the flat panel at different positions , and calculate the three-dimensional information of the plane plate at different positions according to the calibration data; In each area, the absolute phase of each pixel of the imaging device in the absolute phase distribution map of the flat plate is obtained, and according to the relationship between the three-dimensional information of each flat plate and the absolute phase of the corresponding pixel The mapping relation establishes the three-dimensional mapping coefficient table of the corresponding area; Use the projection device to project the target pattern to the measured object, collect the target focal scan image of the measured object through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image and calculate the absolute phase of the target image Distribution; Obtain the absolute phase of each pixel of the target image in the absolute phase distribution map of the target image, and search for the corresponding three-dimensional mapping coefficient in the three-dimensional mapping coefficient table of the corresponding area according to the area to which the absolute phase belongs, using the The three-dimensional mapping coefficients are calculated to obtain the corresponding three-dimensional point coordinates in space; The projecting target pattern to the measured object by using the projection device, collecting the target focal scan image of the measured object through the imaging device, and performing deblurring processing on the target focal scan image to obtain the target image and calculating the target image Absolute phase profile, including: Inputting the focal scan image of the target into an integral point spread function to perform a deconvolution operation to obtain a deblurred target image; The calculation formula of the integral point spread function is as follows: Among them, r is the distance from the center of the circle of confusion where the object point is imaged on the sensor plane of the imaging device; b ₀ is the diameter of the circle of confusion that the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at 0 time; b ₁ is the spot diameter of the object point focused on the sensor plane of the imaging device; _b2 is the diameter of the circle of confusion when the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at half a cycle T; C ₁ and C ₂ for two constants. 2. The high-precision three-dimensional reconstruction method based on a large depth of field according to claim 1, wherein, after the large depth of field measurement scene is divided into regions, it includes: Using a calibration algorithm to calibrate the positions of the imaging device and the projection device; Obtaining the maximum and minimum values of the total control current measured by the zoom lens of the imaging device in the large depth of field measurement scene, and the corresponding area control current value when the zoom lens of the imaging device focuses on the center position of each area, and Record the maximum and minimum values of the total control current and the regional control current value corresponding to each region. 3. The high-precision three-dimensional reconstruction method based on a large depth of field according to claim 1, wherein said utilizing a three-dimensional measurement system to carry out binocular vision stereo calibration for each divided area to obtain calibration data, including: Taking the optical center of the imaging device as the origin, and taking the optical axis of the imaging device as the Z axis, an imaging device coordinate system is established; taking the optical center of the projection device as the origin, and taking the optical axis of the projection device For the Z axis, establish the coordinate system of the projection device; Obtain the conversion relationship between the intrinsic parameters of the imaging device and the coordinate system of the imaging device and the conversion relationship between the intrinsic parameters of the projection device and the coordinate system of the projection device by using a binocular vision stereo calibration algorithm, and calculate the imaging device The conversion relationship between the coordinate system and the coordinate system of the projection device is used to obtain the calibration data. 4. The high-precision three-dimensional reconstruction method based on a large depth of field according to claim 1, wherein the calculation of the three-dimensional information of the plane plate at different positions according to the calibration data includes: The three-dimensional information is calculated according to the following formula: _Among them, s _C and s _P are the scale factors of the imaging device and the projection device, respectively, K _C and K _P are the internal parameter matrices of the imaging device and the projection device, respectively, MC is the external parameter matrix of the imaging device, I is the identity matrix, ( u _C , v _C ) and ( u _P , v _P ) are the image coordinates of the imaging device and the projection device after the distortion parameters of the three-dimensional measurement system are corrected, and T is the transpose of the matrix. 5. The high-precision three-dimensional reconstruction method based on a large depth of field according to claim 1, wherein, in each region, the absolute phase distribution map of each pixel of the imaging device on the flat plate is obtained The absolute phase in, and according to the mapping relationship between the three-dimensional information of each said flat plate and the absolute phase of the corresponding pixel point, establish a three-dimensional mapping coefficient table for the corresponding area, including: According to the three-dimensional information corresponding to the pixel point, the three-dimensional mapping coefficient is calculated according to the following formula, and the three-dimensional mapping coefficient table is established: Among them, α _n , c _X , b _n , c _Y , c _n and c _Z are three-dimensional mapping coefficients, N is the polynomial order, and Ф is the absolute phase of the corresponding pixel. 6. The high-precision three-dimensional reconstruction method based on a large depth of field according to claim 1, wherein the absolute phase of each pixel of the target image in the absolute phase distribution map of the target image is obtained, and according to The area to which the absolute phase belongs searches for the corresponding three-dimensional mapping coefficient in the three-dimensional mapping coefficient table of the corresponding area, and uses the three-dimensional mapping coefficient to calculate the corresponding three-dimensional point coordinates in space, including: The coordinates of the three-dimensional point in the space are calculated by the following formula: Among them, { a _n , b _n , c _n } are the three-dimensional mapping coefficients of the corresponding area, Ф is the absolute phase of the pixel, and N is the polynomial order. 7. A high-precision three-dimensional reconstruction device based on a large depth of field, characterized in that it comprises: The area division unit is used to perform area division on the large depth of field measurement scene; The calibration data acquisition unit is used to use the three-dimensional measurement system to perform binocular vision stereo calibration on each divided area to obtain calibration data; wherein the three-dimensional measurement system includes an imaging device and a projection device; The three-dimensional information acquisition unit is used to project a specified pattern to the flat panel at different positions by using the projection device in different areas, and collect the flat panel images of the flat flat panel at different positions through the imaging device, and calculate the position of the flat flat panel at Absolute phase distribution diagrams at different positions, and calculate the three-dimensional information of the flat plate at different positions according to the calibration data; A three-dimensional mapping coefficient table acquisition unit, configured to acquire the absolute phase of each pixel of the imaging device in the absolute phase distribution diagram of the flat plate in each area, and obtain the absolute phase according to the three-dimensional information of each of the flat plates Establish a three-dimensional mapping coefficient table for the corresponding area with the mapping relationship between the absolute phase of the corresponding pixel point; The target focal scan image acquisition unit is used to project the target pattern to the object under test by using the projection device, collect the target focal scan image of the object under test through the imaging device, and perform deblurring processing on the target focal scan image to obtain the target image and calculating the absolute phase distribution map of the target image; A spatial three-dimensional point coordinate acquisition unit, configured to acquire the absolute phase of each pixel point of the target image in the absolute phase distribution map of the target image, and search in the three-dimensional mapping coefficient table of the corresponding area according to the area to which the absolute phase belongs Corresponding three-dimensional mapping coefficients, using the three-dimensional mapping coefficients to calculate corresponding three-dimensional point coordinates in space; The target focal scan image acquisition unit includes: A deblurring processing unit, configured to input the target focal scan image to an integral point spread function for deconvolution operation, to obtain a deblurred target image; An integral point spread function calculation unit, the calculation formula for the integral point spread function is as follows: Among them, r is the distance from the center of the circle of confusion where the object point is imaged on the sensor plane of the imaging device; b ₀ is the diameter of the circle of confusion that the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at 0 time; b ₁ is the spot diameter of the object point focused on the sensor plane of the imaging device; _b2 is the diameter of the circle of confusion when the object point is imaged on the sensor plane of the imaging device when the current value of the electronic zoom lens is controlled at half a cycle T; C ₁ and C ₂ for two constants. 8. A computer device, comprising a memory, a processor, and a computer program stored on the memory and operable on the processor, characterized in that, when the processor executes the computer program, the computer program according to claim The high-precision three-dimensional reconstruction method based on a large depth of field described in any one of 1 to 6. 9. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor executes any one of claims 1 to 6. A high-precision 3D reconstruction method based on a large depth of field described in this item.