CN116295113A - Polarization three-dimensional imaging method integrating fringe projection - Google Patents
Polarization three-dimensional imaging method integrating fringe projection Download PDFInfo
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Abstract
The invention discloses a polarization three-dimensional imaging method fusing stripe projection, which comprises the following steps: acquiring a polarization sub-image of the target surface; establishing a micro-surface element normal vector mathematical model on the target surface and calculating zenith angles and azimuth angles; projecting a plurality of sinusoidal grating fringe patterns with continuous phase change to the surface of the target by using a projector, synchronously acquiring by using a camera, and calculating absolute phase information of the target; obtaining point cloud data of each point on the target surface by calibrating a camera and a projector through absolute phase information, and calculating gradient information of each point according to the point cloud data; determining a theoretical range interval of the azimuth angle based on the gradient information and the normal vector mathematical model; correcting the azimuth angle according to the theoretical interval range; reconstructing the three-dimensional morphology of the target based on the zenith angle and the corrected azimuth angle. The method realizes the accurate reconstruction of the three-dimensional morphology of the target by correcting the azimuth angle, has a simple structure of a device required by the method, and is beneficial to reducing the calculation efficiency and the cost.
Description
Technical Field
The invention belongs to the technical field of optical imaging, and particularly relates to a polarization three-dimensional imaging method fused with fringe projection.
Background
The modern photoelectronic technology is used as a detection means, has high-precision, non-contact, anti-interference, high-speed and other robustness, is a main direction of development in the current optical imaging field, and is developing towards intellectualization, automation, micromation and diversification. The conventional photoelectric detection technology mainly acquires light intensity information, namely two-dimensional information, in a target scene, and the information of a plurality of important physical quantities in the target scene is lost in the acquisition process. After the intensity information is acquired, the information under different scenes is generally interpreted by combining methods such as feature detection and matching, target extraction and tracking, so that the imaging effect is limited, and the three-dimensional shape information of the object cannot be accurately interpreted. The three-dimensional imaging technology is used as an acquisition means for sensing important information of a real three-dimensional world, can provide depth information which cannot be acquired by a two-dimensional image, and provides data support and theoretical basis for the aspects of reconstructing the real geometric shape of a target, subsequent three-dimensional identification, detection and the like. The structured light three-dimensional reconstruction technology based on stripe projection is used as a non-contact active measurement means, and by projecting a specific pattern sequence onto the surface of a target to be measured, the structured light three-dimensional reconstruction technology can be considered as adding stable and remarkable characteristic points to the surface of the target to be measured to a certain extent, and shooting the deformation coding stripe pattern modulated by the target is beneficial to acquiring accurate three-dimensional contour data from an image carrying three-dimensional morphology information of the surface of the target.
The polarization three-dimensional imaging technology is a passive imaging method for recovering the surface of the target by utilizing the light polarization characteristic, and can realize three-dimensional reconstruction of the target by only establishing a mapping relation between three-dimensional contour characteristic information of the surface of the target and the polarization characteristic of emergent light waves of the surface based on the Fresnel principle, and has the advantages of high cost performance, simple information acquisition mode and the like, and provides possibility for high-precision three-dimensional reconstruction by utilizing the polarization characteristic of the target. However, in the process of interpreting the polarization characteristics of the emergent light on the target surface, the problem of singularity exists in the normal vector solution, so that the integral reconstruction result is distorted. Therefore, solving the problem of singularity becomes a key point of the polarization three-dimensional imaging technology.
In the prior art, a polarization three-dimensional reconstruction method combined with a Kinect depth sensor exists. The method mainly uses rough depth acquired by Kinect as priori information, and associates a surface normal acquired from a rough depth map with a normal acquired from a polarization clue, namely, fuses a high-resolution target surface normal direction available in a visible light polarization image with low-resolution depth information acquired by a camera, and eliminates the problem of low-frequency azimuth ambiguity by applying additional constraint, thereby realizing correction of the normal map and super-resolution information fusion of the depth image and improving imaging quality. However, in practical applications, the method uses more than one depth sensor, which results in more complex system structure and generally requires higher computing performance.
Therefore, on the one hand, the traditional photoelectric detection method is limited by the reasons that only the two-dimensional information of the target can be acquired and is limited by a detector and the like, and meanwhile, important information such as spectrum, phase, polarization and the like in a light field is lost while the target information is acquired, so that the imaging effect is limited, the problem that characteristic information is difficult to solve and the three-dimensional shape information of an object cannot be accurately interpreted is easily caused. On the other hand, in the existing reconstruction method based on a plurality of sensors, the characteristic matching among the sensors is needed, so that the calculated amount is large, the system structure is more complex to a certain extent, the calculated time is long, and certain errors and influences exist on the reconstruction result and accuracy.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a polarization three-dimensional imaging method fused with fringe projection. The technical problems to be solved by the invention are realized by the following technical scheme:
the invention provides a polarization three-dimensional imaging method fused with fringe projection, which comprises the following steps:
acquiring a polarization sub-image of the target surface;
establishing a micro-surface element normal vector mathematical model on the target surface, and calculating polarization characteristic parameters by utilizing the polarization sub-image, wherein the polarization characteristic parameters comprise zenith angle theta and azimuth angle
Projecting a plurality of sinusoidal grating fringe patterns with continuous phase change to the surface of the target by using a projector, synchronously acquiring by using a camera, and calculating absolute phase information of the target;
obtaining point cloud data of each point on the target surface by calibrating a camera and a projector through the absolute phase information, and calculating gradient information of each point according to the point cloud data;
determining a theoretical range interval of an azimuth angle based on the gradient information and the normal vector mathematical model;
according to the theoretical interval range and the azimuth angle
Correcting;
based on zenith angle θ and corrected azimuth angle
And integrating the normal vector of the target surface by using an integral reconstruction algorithm to reconstruct the three-dimensional morphology of the target.
In one embodiment of the invention, the step of acquiring a polariton image of the target surface comprises:
under indoor environment, using integrating sphere to simulate natural light illumination;
sequentially rotating a polaroid in front of a camera lens to a preset angle, and collecting reflected light of a target surface by using an imaging detector to obtain polarized wave images of different angles; wherein the preset angle comprises 0 °, 45 °, 90 ° and 135 °;
and carrying out target background segmentation on the polarized sub-images under different angles.
In one embodiment of the present invention, the step of creating a mathematical model of a micro-surface normal vector on the target surface and calculating the polarization characteristic parameter using the polarization sub-image includes:
according to the mapping relation between the three-dimensional contour information of the target surface micro-surface element and the normal vector of the target surface, establishing a micro-surface element normal vector mathematical model on the target surface and calculating the zenith angle theta according to the following formula:
wherein n represents the refractive index of the target surface, ρ represents the degree of polarization of the polarized image obtained by the representation method using Stockes vector to describe the intensity and polarization state of the light wave, and θ is located
Between them;
the polarization phase angle phi of the polariton image is calculated according to the following formula:
wherein I is max 、I min Respectively representing the maximum light intensity and the minimum light intensity obtained by rotating the polaroid for one circle, wherein I represents the illumination intensity when the polarization phase angle is phi, and xi represents the included angle between the light transmission axis of the polaroid and the initial position of the polaroid, wherein phi is between 0 and 2 pi;
calculating azimuth angle using said polarization phase angle phi
In one embodiment of the present invention,
or->
In one embodiment of the present invention, the step of projecting a plurality of sinusoidal grating fringe patterns having continuous phase variations onto a target surface using a projector and synchronously acquiring using a camera, calculating absolute phase information of the target, comprises:
transmitting a plurality of sinusoidal grating fringe patterns with continuous phase change to the target surface by using a projector, and respectively synchronizing the sinusoidal grating fringe patterns by using a camera to obtain a plurality of images;
based on the images, a multi-frequency heterodyne method in a time phase unwrapping algorithm is adopted for phase unwrapping, and absolute phase information is obtained.
In one embodiment of the present invention, the mathematical model of the normal vector includes an X-axis, a Y-axis, and a Z-axis, wherein the X-axis is perpendicular to the Y-axis and is located in a tangential plane of each point, the Z-axis intersects the X-axis and the Y-axis, the Z-axis is perpendicular to the tangential plane, and the gradient information includes gradient field information p of the normal vector of the target surface in the X-axis direction sl Gradient field information q in the Y-axis direction sl ；
Determining a theoretical range interval of azimuth angles based on the gradient information and the normal vector mathematical model, wherein the theoretical range interval comprises the following steps:
based on priori gradient information and the normal vector mathematical model, respectively determining the target surface p sl The relation between the value of (a) and the azimuth angle and q sl The value relation between the value of the azimuth angle;
according to the target surface p sl The relation between the value of (a) and the azimuth angle and q sl And determining the theoretical range interval of the azimuth angle of the target surface according to the value relation between the value of the azimuth angle and the value of the azimuth angle.
In one embodiment of the present invention, the azimuth angle is determined according to the theoretical block range
Before the step of correcting, the method further comprises the following steps:
judging the azimuth angle
Whether it is within the theoretical range of azimuth angles.
In one embodiment of the present invention, the azimuth angle is determined according to the theoretical block range
A step of performing correction, comprising:
when the azimuth angle is
Outside the theoretical range of azimuth, azimuth is +.>
Turning 180 deg. to obtain corrected azimuth angle +.>
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a polarization three-dimensional imaging method integrating fringe projection, which utilizes important phase information and polarization information in a light field to realize accurate reconstruction of a three-dimensional shape of a target through correction of azimuth angles; in addition, the invention has simple structure, only one image acquisition sensor is needed except the projection optical machine, and the characteristic matching process among multiple sensors is not needed, so that the calculation efficiency and the cost are reduced to a certain extent.
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Drawings
FIG. 1 is a flow chart of a method for polarized three-dimensional imaging of fused fringe projection provided by an embodiment of the invention;
FIG. 2 is a schematic diagram of a mathematical model of a normal vector provided by an embodiment of the present invention;
FIG. 3 shows p provided by an embodiment of the present invention sl A value relation diagram of the value of the azimuth angle;
FIG. 4 is a diagram of q provided by an embodiment of the present invention sl A value relation diagram of the value of the azimuth angle;
fig. 5 is a schematic diagram of a theoretical range interval of a target surface azimuth according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.
Fig. 1 is a flowchart of a polarization three-dimensional imaging method for fusion fringe projection provided by an embodiment of the invention. As shown in fig. 1, an embodiment of the present invention provides a polarization direction correction method for fusion fringe projection, including:
s1, acquiring a polarization sub-image of a target surface;
s2, establishing a micro-surface element normal vector mathematical model on the target surface, and calculating polarization characteristic parameters by utilizing a polariton image, wherein the polarization characteristic parameters comprise zenith angle theta and azimuth angle
S3, projecting a plurality of sinusoidal grating fringe patterns with continuous phase changes to the surface of the target by using a projector, synchronously acquiring by using a camera, and calculating absolute phase information of the target;
s4, obtaining point cloud data of each point on the target surface by calibrating the camera and the projector and utilizing absolute phase information, and calculating gradient information of each point according to the point cloud data;
s5, determining a theoretical range interval of the azimuth angle based on gradient information and a normal vector mathematical model;
s6, according to the theoretical interval range, the azimuth angle
Correcting;
s7, based on zenith angle theta and corrected azimuth angle
Target surface using integral reconstruction algorithmAnd (3) integrating normal vectors to reconstruct the three-dimensional morphology of the target.
Optionally, in the step S1, the step of acquiring a polarizer image of the target surface includes:
under indoor environment, using integrating sphere to simulate natural light illumination;
sequentially rotating a polaroid in front of a camera lens to a preset angle, and collecting reflected light of a target surface by using an imaging detector to obtain polarized wave images of different angles; wherein the preset angle comprises 0 °, 45 °, 90 ° and 135 °;
and carrying out target background segmentation on the polarized sub-images under different angles.
Specifically, natural light illumination is simulated through an integrating sphere in an indoor environment, then reflected light of a target surface is collected through an imaging detector, and a polaroid in front of a camera lens can be rotated in the collection process, so that polarized light images under four preset angles of 0 degrees, 45 degrees, 90 degrees and 135 degrees are obtained. After obtaining the polarized wave images with different angles, a reasonable threshold value is set to divide the target area and the background area in each polarized wave image. It should be noted that, in this embodiment, any existing image processing algorithm may be used to perform object segmentation on the polarization sub-image, so that details are not repeated here.
In the step S2, a mathematical model of a micro-surface element normal vector is built on the target surface, and the step of calculating the polarization characteristic parameter by using the polarization sub-image includes:
s201, establishing a micro-surface normal vector mathematical model on a target surface according to the mapping relation between the three-dimensional contour information of the target surface micro-surface element and the target surface normal vector;
s202, acquiring the polarization degree rho of the polarized oscillator image by using the polarized oscillator image according to a representation method of describing the light wave intensity and the polarization state by using Stockes vectors, and calculating the zenith angle theta according to the following formula:
wherein n represents the refraction of the target surfaceEmissivity, theta is located at
Between them;
s203, since the reflected light intensity of the target surface changes along with the change of the angle of the polarizer, the change of the micro-bin intensity information can be expressed as:
wherein I is max 、I min Respectively representing the maximum light intensity and the minimum light intensity obtained by rotating the polaroid for one circle, wherein I represents the illumination intensity when the polarization phase angle is phi, and xi represents the included angle between the transmission axis of the polaroid and the initial position of the polaroid, and phi is between 0 and 2 pi.
FIG. 2 is a schematic diagram of a mathematical model of a normal vector provided by an embodiment of the present invention. In this embodiment, a normal vector mathematical model for characterizing the three-dimensional profile information of the target can be established based on the mapping relationship between the three-dimensional profile information of the target surface micro-surface element and the normal vector. Specifically, as shown in fig. 2, the normal vector mathematical model includes an X axis, a Y axis, and a Z axis, wherein the X axis is perpendicular to the Y axis and is located in a tangential plane of each point on the target surface, the Z axis intersects the X axis and the Y axis, the Z axis is perpendicular to the tangential plane, it should be understood that zenith angle refers to an angle between a normal vector direction and the Z axis, and azimuth angle refers to an angle between a projection of the normal vector on the XoY plane and the X axis direction.
Referring to the mathematical model of normal vector shown in fig. 2, the normal vector at a point z=f (x, y) on the target surface is expressed as
Normal vector->
Is subject to the polarization characteristic parameters zenith angle theta and azimuth angle +.>
Therefore, need toThese two parameters are solved for using the polarization properties of the target. As known from the Fresnel formula, the intensity of the reflected light changes after passing through the polarizer, and in the process of generating the polarizer image, the maximum intensity and the minimum intensity obtained by the pixels in the polarization sub-image are respectively recorded as I max 、I min The included angle between the transmission axis of the polaroid and the initial reference position is xi, and the polarization phase angle of the reflected light is phi. Based on three-dimensional reconstruction of a polarization imaging principle, the embodiment adopts the thought of diffuse reflection target reconstruction, the reflectivity of a diffuse reflection target is generally in the range of 1.4-1.6, the embodiment sets the refractive index of the target surface to n=1.5, and then the zenith angle theta and azimuth angle phi of the normal vector of the target surface can be solved by using the polarization degree rho and the polarization phase angle phi>
Illustratively:
in this embodiment, the azimuth angle is solved by using the polarization information
There is a degree of singularity that,
or->
Optionally, in the step S3, the step of projecting a plurality of sinusoidal grating fringe patterns with continuous phase changes to the target surface by using a projector and synchronously collecting by using a camera, and calculating absolute phase information of the target includes:
transmitting a plurality of sinusoidal grating fringe patterns with continuous phase change to the target surface by using a projector, and respectively synchronizing the sinusoidal grating fringe patterns by using a camera to obtain a plurality of images;
based on a plurality of images, a multi-frequency heterodyne method in a time phase unwrapping algorithm is adopted for phase unwrapping, and absolute phase information is obtained.
In the polarization three-dimensional imaging method of the fusion fringe projection provided by the invention, the azimuth angle is calculated
Then, the point cloud data carrying the prior gradient information of the target surface is required to be acquired by further utilizing a fusion fringe projection mode.
Specifically, an industrial camera and a projector are adopted to build a monocular structured light system, a plurality of sinusoidal grating fringe patterns with continuous phase change are projected to the surface of a target through the projector, the modulated fringes are shot by the camera to extract phase information, and the phase expansion is carried out by adopting a multi-frequency heterodyne method in a time phase expansion algorithm to obtain final absolute phase information. Further, system calibration is carried out through a monocular inverse camera model, a projection matrix of a camera and a projector is solved, and acquisition of point cloud data is completed according to the conversion relation from absolute phase information to three-dimensional coordinates.
In addition, in step S4, an area of interest may be set on the target surface, and after performing gaussian smoothing on the point cloud data of each point in the area of interest, gradient information { p } of each point in the area of interest is calculated sl (x,y),q sl (x, y) }, wherein p sl Gradient field information of normal vector of target surface in X-axis direction, q sl Gradient field information in the Y-axis direction for the normal vector of the target surface. Of course, in some other embodiments of the present invention, the gradient information { p } may be calculated directly by using all the point cloud data of the target surface without setting the region of interest sl (x,y),q sl (x, y) }. The invention is not limited in this regard.
In the step S5, the step of determining the theoretical range interval of the azimuth angle based on the gradient information and the normal vector mathematical model includes:
s501, determining target surfaces p based on priori gradient information and normal vector mathematical models sl The relation between the value of (a) and the azimuth angle and q sl The value relation between the value of the azimuth angle;
s502, according to the target surface p sl The relation between the value of (a) and the azimuth angle and q sl And determining the theoretical range interval of the azimuth angle of the target surface according to the value relation between the value of the azimuth angle and the value of the azimuth angle.
With continued reference to fig. 2, in this embodiment the normal vector at a point z=f (x, y) on the target surface
Can be expressed as:
the following relationship can be simplified from the above equation:
further, the method comprises the steps of,
wherein n is x 、n y And n z Normal vectors respectively representing the points
Components in the X-axis, Y-axis and Z-axis, θ represents the normal vector of the point +.>
Zenith angle of>
Representing the normal vector of the point->
Is a bearing angle of (c).
Based on the above analysis, for the point z=f (X, Y), the gradient field information p of the normal vector in the X-axis direction and the gradient field information q of the Y-axis direction will jointly determine the azimuth angle
Therefore, the present embodiment can use the gradient information { p } sl (x,y),q sl And (x, y) as prior information, correcting an azimuth angle singularity problem obtained based on the solution of the polarization sub-images, and determining the uniqueness of the target surface micro-surface element normal vector direction.
FIG. 3 shows p provided by an embodiment of the present invention sl FIG. 4 is a schematic diagram showing the relationship between the values of the azimuth angle and q provided by the embodiment of the invention sl Fig. 5 is a schematic diagram of a theoretical range interval of the azimuth angle of the target surface according to the embodiment of the invention. As shown in fig. 3-5, the plane is divided into four regions by a horizontal axis and a vertical axis, and a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant are formed starting from the upper right in the counterclockwise direction. Referring to FIG. 3, the horizontal axis represents p sl Establishing a cross plane coordinate system, dividing the plane into four different quadrants uniformly along the transverse and longitudinal axes, wherein each quadrant corresponds to the four different quadrants where the azimuth angle value may be located, namely 0-2pi is divided into four parts uniformly, wherein the left area of the longitudinal axis represents p sl >The range section and right area where the azimuth angle value is located at 0 represents p sl <The range of azimuth angle values at 0 is obviously combined with
And sine and cosine function properties are as follows: when p is sl >At 0, the azimuth angle is within the range +.>
The second quadrant and the third quadrant in fig. 3; when p is sl <At 0, the azimuth angle is within the range +.>
And->
I.e. the first quadrant and the fourth quadrant in fig. 3.
Likewise, referring to FIG. 4, the vertical axis represents q sl The lower area of the horizontal axis represents q sl >The range interval and upper region where the azimuth angle value is located at 0 represents q sl <And the azimuth angle value is in the range interval when 0. When q sl >At 0, azimuth
The range of the values of (a) is pi-2 pi, namely a third quadrant and a fourth quadrant in the graph 4; when q sl <Azimuth angle +.>
The range of values of (2) is 0-pi, namely the first quadrant and the second quadrant in fig. 4.
Further, in combination with fig. 3 and 4, p is sl >0 and q sl >0, taking the intersection of the respective interval ranges as an example, the theoretical interval of the azimuth angle can be determined as
I.e. the third quadrant shown in fig. 5.
In the present embodiment, the azimuth angle is determined according to the theoretical interval range
Before the step of correcting, the method further comprises the following steps:
determining azimuth angle
Whether it is within the theoretical range of azimuth angles.
Specifically, if the azimuth angle is calculated
If the azimuth angle does not fall within the theoretical range, the azimuth angle is +.>
The value is inverted pi to obtain corrected azimuth angle +.>
Thereby utilizing zenith angle θ and corrected azimuth angle +.>
And integrating the normal vector of the target surface by using an integral reconstruction algorithm to obtain the polarization azimuth correction of the target.
According to the above embodiments, the beneficial effects of the invention are as follows:
the invention provides a polarization three-dimensional imaging method integrating fringe projection, which utilizes important phase information and polarization information in a light field to realize accurate reconstruction of a three-dimensional shape of a target through correction of azimuth angles; in addition, the invention has simple structure, only one image acquisition sensor is needed except the projection optical machine, and the characteristic matching process among multiple sensors is not needed, so that the calculation efficiency and the cost are reduced to a certain extent.
In the description of the present invention, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.
Although the present application has been described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the figures, the disclosure, and the appended claims.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (8)
1. A polarized three-dimensional imaging method fusing fringe projection, comprising:
acquiring a polarization sub-image of the target surface;
establishing a micro-surface element normal vector mathematical model on the target surface, and calculating polarization characteristic parameters by utilizing the polarization sub-image, wherein the polarization characteristic parameters comprise zenith angle theta and azimuth angle
Projecting a plurality of sinusoidal grating fringe patterns with continuous phase change to the surface of the target by using a projector, synchronously acquiring by using a camera, and calculating absolute phase information of the target;
obtaining point cloud data of each point on the target surface by calibrating a camera and a projector through the absolute phase information, and calculating gradient information of each point according to the point cloud data;
determining a theoretical range interval of an azimuth angle based on the gradient information and the normal vector mathematical model;
according to the theoretical interval range and the azimuth angle
Correcting;
based on zenith angle θ and corrected azimuth angle
And integrating the normal vector of the target surface by using an integral reconstruction algorithm to reconstruct the three-dimensional morphology of the target.
2. The polarized three-dimensional imaging method of fused fringe projection of claim 1 wherein the step of acquiring a polarized image of the target surface comprises:
under indoor environment, using integrating sphere to simulate natural light illumination;
sequentially rotating a polaroid in front of a camera lens to a preset angle, and collecting reflected light of a target surface by using an imaging detector to obtain polarized wave images of different angles; wherein the preset angle comprises 0 °, 45 °, 90 ° and 135 °;
and carrying out target background segmentation on the polarized sub-images under different angles.
3. The polarization three-dimensional imaging method of fused fringe projection of claim 2, wherein the step of creating a micro-surface element normal vector mathematical model on the target surface and calculating polarization characteristic parameters using the polarization sub-images comprises:
according to the mapping relation between the three-dimensional contour information of the target surface micro-surface element and the normal vector of the target surface, establishing a micro-surface element normal vector mathematical model on the target surface and calculating the zenith angle theta according to the following formula:
wherein n represents the refractive index of the target surface, ρ represents the degree of polarization of the polarized image obtained by the representation method using Stockes vector to describe the intensity and polarization state of the light wave, and θ is located
Between them;
the polarization phase angle phi of the polariton image is calculated according to the following formula:
wherein I is max 、I min Respectively representing the maximum light intensity and the minimum light intensity obtained by rotating the polaroid for one circle, wherein I represents the illumination intensity when the polarization phase angle is phi, and xi represents the included angle between the light transmission axis of the polaroid and the initial position of the polaroid, wherein phi is between 0 and 2 pi;
calculating azimuth angle using said polarization phase angle phi
4. A polarization three-dimensional imaging method of fusion fringe projection as recited in claim 3, wherein,
or (b)
5. The polarization three-dimensional imaging method of fused fringe projection of claim 1, wherein the step of projecting a plurality of sinusoidal grating fringe patterns having continuous phase changes to the target surface with a projector and synchronously acquiring with a camera, calculating absolute phase information of the target, comprises:
transmitting a plurality of sinusoidal grating fringe patterns with continuous phase change to the target surface by using a projector, and respectively synchronizing the sinusoidal grating fringe patterns by using a camera to obtain a plurality of images;
based on the images, a time phase unwrapping algorithm is adopted to conduct phase unwrapping, and absolute phase information is obtained.
6. The polarization three-dimensional imaging method of fused fringe projection of claim 1, wherein said mathematical model of normal vector comprises an X-axis, a Y-axis, and a Z-axis, wherein the X-axis is perpendicular to the Y-axis and is located in a tangential plane of said points, the Z-axis intersects the X-axis, the Y-axis, the Z-axis is perpendicular to said tangential plane, said gradient information comprises gradient field information p of normal vector of the target surface in X-axis direction sl Gradient field information q in the Y-axis direction sl ；
Determining a theoretical range interval of azimuth angles based on the gradient information and the normal vector mathematical model, wherein the theoretical range interval comprises the following steps:
based on priori gradient information and the normal vector mathematical model, respectively determining the target surface p sl The relation between the value of (a) and the azimuth angle and q sl The value relation between the value of the azimuth angle;
according to the target surface p sl The relation between the value of (a) and the azimuth angle and q sl And determining the theoretical range interval of the azimuth angle of the target surface according to the value relation between the value of the azimuth angle and the value of the azimuth angle.
7. The polarization three-dimensional imaging method of fused fringe projection of claim 6, wherein the azimuth angle is based on said theoretical interval range
Before the step of correcting, the method further comprises the following steps:
judging the azimuth angle
Whether it is within the theoretical range of azimuth angles.
8. The polarization three-dimensional imaging method of fusion fringe projection of claim 7, wherein the azimuth angle is based on the theoretical interval range
A step of performing correction, comprising:
when the azimuth angle is
Outside the theoretical range of azimuth, azimuth is +.>
Turning 180 deg. to obtain corrected azimuth angle +.>
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| CN116592794A (en) * | 2023-07-17 | 2023-08-15 | 南京理工大学 | Rapid three-dimensional reconstruction method based on polarized structured light |
| CN117523112A (en) * | 2024-01-05 | 2024-02-06 | 深圳市宗匠科技有限公司 | Three-dimensional model building method and system, control equipment and storage medium thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116592794A (en) * | 2023-07-17 | 2023-08-15 | 南京理工大学 | Rapid three-dimensional reconstruction method based on polarized structured light |
| CN116592794B (en) * | 2023-07-17 | 2023-11-24 | 南京理工大学 | Rapid three-dimensional reconstruction method based on polarized structured light |
| CN117523112A (en) * | 2024-01-05 | 2024-02-06 | 深圳市宗匠科技有限公司 | Three-dimensional model building method and system, control equipment and storage medium thereof |
| CN117523112B (en) * | 2024-01-05 | 2024-05-17 | 深圳市宗匠科技有限公司 | Three-dimensional model building method and system, control equipment and storage medium thereof |
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