CN116883517A - Camera parameter calibration method without overlapping view fields based on plane mirror - Google Patents
Camera parameter calibration method without overlapping view fields based on plane mirror Download PDFInfo
- Publication number
- CN116883517A CN116883517A CN202311151609.4A CN202311151609A CN116883517A CN 116883517 A CN116883517 A CN 116883517A CN 202311151609 A CN202311151609 A CN 202311151609A CN 116883517 A CN116883517 A CN 116883517A
- Authority
- CN
- China
- Prior art keywords
- camera
- coordinate system
- plane mirror
- virtual camera
- virtual
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000006243 chemical reaction Methods 0.000 claims abstract description 82
- 239000011159 matrix material Substances 0.000 claims description 87
- 238000013519 translation Methods 0.000 claims description 56
- 230000009466 transformation Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000009825 accumulation Methods 0.000 description 2
- 230000036544 posture Effects 0.000 description 2
- 230000008685 targeting Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012821 model calculation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/80—Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
- G06T7/85—Stereo camera calibration
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T3/00—Geometric image transformations in the plane of the image
- G06T3/60—Rotation of whole images or parts thereof
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/70—Determining position or orientation of objects or cameras
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention relates to a camera parameter calibration method based on a plane mirror and without overlapping view fields, which comprises the following steps: s10, constructing a binocular system, wherein the binocular system comprises a first camera and a second camera with opposite view field directions, and a plane mirror is arranged in the view field range of the second camera, so that a virtual camera corresponding to the mirror image of the second camera in the plane mirror and the first camera form a new binocular system with overlapped view fields; s20, calculating a first conversion relation between the second camera and the virtual camera; s30, calculating a second conversion relation between the virtual camera and the first camera; s40, calculating a third conversion relation between the first camera and the second camera based on the first conversion relation and the second conversion relation so as to realize camera parameter calibration of non-overlapping fields of view; according to the invention, the camera coordinate system of the plane mirror and the camera coordinate system of the virtual camera are set as the intermediate coordinate system, so that the calibration unification of the two cameras is completed, and the global calibration of the camera without overlapping view fields is realized.
Description
Technical Field
The invention relates to the technical field of camera parameter calibration, in particular to a camera parameter calibration method based on a plane mirror and without overlapping view fields.
Background
In recent years, most vision measurement students develop research work on camera calibration of non-overlapping fields of view, and many application methods are proposed from different angles, and a part of calibration algorithms are briefly described below.
(1) Hand-eye calibration. The method is to compare the camera with the eye and the mechanical arm as the hand, and can be divided into two cases: the camera is fixed on the mechanical arm, and in this case, the relation between the coordinate system of the camera and the coordinate system of the mechanical arm needs to be converted; the other is that the camera is separated from the mechanical arm, and the relative positions of eyes and hands are unchanged. This is the case for solving the relationship of the camera coordinate system and the base coordinate system. The hand-eye calibration method is a new method developed and tested by Guan et al, and is proposed under the influence of Zhang Zhengyou calibration and Tsai calibration methods. This method allows simultaneous calibration of the internal and external parameters of the camera, but due to the "hand" limitation, the visual measurement is also limited when the camera is mounted on the ceiling.
(2) One-dimensional targeting and special targeting. The one-dimensional target with high precision and large size is convenient to process, so that the one-dimensional target is particularly suitable for high-precision calibration under a large view field or under a non-overlapping view field. Liu Zhen camera calibration without overlapping fields of view is performed by using a one-dimensional target, wherein characteristic points with specified spacing distances on the one-dimensional target are extracted, and then a translation vector is calculated according to a known distance as a constraint condition, but the number of the characteristic points which can be extracted is limited due to the limitation of the size of the target, so that the calibration precision is also limited. Although the one-dimensional targets can meet the requirement of partial non-overlapping field-of-view calibration, a single one-dimensional target has certain limitation in the case of multiple targets. Thus, beginning with improving the calibrated targets, researchers have devised specific targets by following different realistic requirements. By assembling two one-dimensional short bars with fixed angle and distance constraint as improved special targets, xie firstly approximately calculates the relative postures of the two cameras by utilizing the unchanged constraint condition of the target, and then improves the relative positions by respectively changing the distance between the light spots of the two one-dimensional short bars, thereby estimating the structural parameters of the target. Liu Zhen uses a connecting rod to fix several sub-targets and uses the condition that the relative position between them is unchanged to solve the external parameters of the camera, but this method is limited by the dimensions of the planar target and the connecting rod, so the application range is severely limited.
(3) Auxiliary equipment method. In the original camera calibration equipment, other auxiliary equipment such as radar, laser range finders, theodolites and the like are innovatively used. Different auxiliary devices different students have different uses in camera calibration. Such as the use of a laser rangefinder, liu Zhen uses the laser rangefinder to obtain the covariance of the laser spot detected by each camera and the distance between the laser spots so that external parameters between different cameras can be calculated. Ortega et al use the laser rangefinder as external information to aid in the calibration process of the distributed camera network. Lu uses two theodolites and one planar target to calibrate the camera. Hesch et al used a six degree of freedom conversion method between robot bodies to calibrate the camera. Kumar, sturm, and Ying et al use flat mirrors to create overlapping fields of view between cameras.
(4) Other methods. In view of various complex calibration environments in reality, students have the ability to calibrate a non-overlapping camera system on a vehicle on line by tracking an arbitrary and fixed calibration object without using a calibration target or other auxiliary equipment in a conventional sense, but by providing a constraint condition by a moving target under a camera lens. There are also time-synchronized pose sequences for each camera used to estimate the positioning of multiple rigidly coupled cameras, as is done by Esquivel et al. However, these calibration methods are generally only suitable for a specific scenario, and cannot be universally applied.
Disclosure of Invention
The invention provides a camera parameter calibration method based on a plane mirror and without overlapping view fields, which can solve the problem that two cameras cannot shoot the same calibration target at the same time and cannot calibrate a coordinate system, and can complete the unified calibration of the two cameras by setting the plane mirror coordinate system and the camera coordinate system of a virtual camera as an intermediate coordinate system, thereby realizing the global calibration of the camera without overlapping view fields, and providing the following technical scheme for solving the technical problems:
as an aspect of the embodiment of the present invention, there is provided a camera parameter calibration method based on non-overlapping fields of view of a plane mirror, including the steps of:
s10, constructing a binocular system, wherein the binocular system comprises a first camera and a second camera with opposite view field directions, and a plane mirror is arranged in the view field range of the second camera, so that a virtual camera corresponding to the mirror image of the second camera in the plane mirror and the first camera form a new binocular system with overlapped view fields;
s20, calculating a first conversion relation between the second camera and the virtual camera;
s30, calculating a second conversion relation between the virtual camera and the first camera;
s40, calculating a third conversion relation between the first camera and the second camera based on the first conversion relation and the second conversion relation so as to realize camera parameter calibration of non-overlapping fields of view;
wherein calculating the first conversion relationship between the second camera and the virtual camera comprises:
calculating a fourth conversion relation between the second camera and the plane mirror;
calculating a fifth conversion relation between the virtual camera and the plane mirror;
calculating a first conversion relationship between the second camera and the virtual camera based on the fourth conversion relationship and the fifth conversion relationship, the first conversion relationship being as follows:
，
wherein ,For the second camera coordinate system->To the virtual camera coordinate system->Rotation matrix of>For the second camera coordinate system->To the virtual camera coordinate system->Is a translation matrix of (a); />For the second camera coordinate system->To plane mirror coordinate systemOXYZIs a rotation matrix of (a);
is a plane mirror coordinate systemOXYZTo the virtual camera coordinate system->Rotation matrix of>Is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Is a rotation matrix of (a);
is a plane mirror coordinate systemOXYZTo the virtual camera coordinate system->Translation matrix of>Is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Is provided for the translation matrix of (a).
Optionally, the fourth conversion relation is a plane mirror coordinate systemOXYZWith a second camera coordinate systemThe conversion relation between, i.e.)>, wherein ,
，
represented as
，/>Is the rotary Euler angle of the plane mirror;
，
wherein ,is the translation distance of the second camera in the X-axis, or->Is the translation distance of the second camera on the Y axis,Is the translational distance of the second camera in the Z-axis.
Optionally, the fifth conversion relation is a plane mirror coordinate systemOXYZCoordinate system with virtual cameraThe conversion relation between, i.e.)>，
wherein ,，/>=/>，/>，
、/>respectively represent the coordinates of the plane mirror->To the virtual camera coordinate system->A rotation matrix and a translation matrix of the same; />By passing throughOXYZThe rotation around the Y axis is obtained and represents the other side of the plane mirror; />Is the translation distance of the virtual camera on the X-axis, or->Is the translation distance of the virtual camera on the Y-axis, or->Is the translation distance of the virtual camera in the Z-axis.
Optionally, calculating a second conversion relationship between the virtual camera and the first camera includes:
defining a virtual camera coordinate systemThe non-homogeneous coordinates of the spatial point under the world coordinate system, the camera coordinate system and the virtual camera coordinate system are respectively P,P1 and P2, there is
，
wherein , and />Respectively represent the first camera coordinate system->A rotation matrix and a translation matrix between the two world coordinate systems; /> and />Respectively represent +.>A rotation matrix and a translation matrix between the two world coordinate systems;
then, the second conversion relationship between the virtual camera and the first camera is expressed as:
，
wherein , and />Respectively represent +.>To a virtual camera coordinate systemRotation matrix and translation matrix of>Representing the coordinate system +.>To the inverse of the rotation matrix of the P-point world coordinate system.
Optionally, calculating a third conversion relationship between the first camera and the second camera based on the first conversion relationship and the second conversion relationship includes:
taking the virtual camera as an intermediate coordinate, obtaining a third conversion relation between the first camera and the second camera as follows:
，
wherein , and />Respectively represent +.>To a second camera coordinate systemA rotation matrix and a translation matrix of (a); /> and />Respectively from a first camera coordinate systemMirror coordinate system>To the first camera coordinate system->A rotation matrix and a translation matrix of (a); /> and />Respectively represent +.>Is a mirror image of the coordinate system of (2)To the virtual camera coordinate system->A rotation matrix and a translation matrix of (a); /> and />Respectively from the second camera coordinate system +.>To the virtual camera coordinate system->Is shifted by a rotation matrix and a translation of (a)A matrix.
Compared with the prior art, the invention has the beneficial effects that:
(1) The coordinate system of the plane mirror is used as an intermediate coordinate system to realize the coordinate unification of the cameras with no overlapping fields of view, and the expansion of the fields of view, even the superposition of the absolute values of the fields of view of the two cameras, is realized; and for objects which are similar to the railway track and are symmetrical left and right or have left and right parts, the simultaneous measurement of the left and right parts can be realized, the data splicing is not needed after the measurement is respectively carried out like the traditional method, and the error accumulation is reduced;
(2) The calibration method of the invention does not need special targets or high-precision accessories, and only uses one auxiliary device, namely a plane mirror, an overlapped view field is created, so that the same target can be shot by two cameras with non-overlapped view fields, and the calibration of the non-overlapped cameras can be realized.
Drawings
FIG. 1 is a flow chart of a method for calibrating camera parameters based on non-overlapping fields of view of a plane mirror;
FIG. 2 is a schematic diagram of a binocular system;
fig. 3 is a flowchart of the conversion relationship between the second camera C2 and the virtual camera V2 thereof.
Detailed Description
Various exemplary embodiments, features and aspects of the invention will be described in detail below with reference to the drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the term "at least one" herein means any one of a plurality or any combination of at least two of a plurality, for example, including at least one of A, B, C, and may mean including any one or more elements selected from the group consisting of A, B and C.
Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better illustration of the invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some instances, well known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present invention.
It will be appreciated that the above-mentioned method embodiments of the present invention can be combined with each other to form a combined embodiment without departing from the principle logic, and the present invention is not repeated herein.
The embodiment provides a camera parameter calibration method based on a plane mirror and without overlapping view fields, as shown in fig. 1, comprising the following steps:
s10, constructing a binocular system, wherein the binocular system comprises a first camera and a second camera with opposite view field directions, and a plane mirror is arranged in the view field range of the second camera, so that a virtual camera corresponding to the mirror image of the second camera in the plane mirror and the first camera form a new binocular system with overlapped view fields;
s20, calculating a first conversion relation between the second camera and the virtual camera;
s30, calculating a second conversion relation between the virtual camera and the first camera;
s40, calculating a third conversion relation between the first camera and the second camera based on the first conversion relation and the second conversion relation so as to achieve camera parameter calibration of the non-overlapping view fields.
Based on the method, the embodiment of the invention can realize the coordinate unification of the cameras with no overlapping fields of view by using the plane mirror coordinate system as the intermediate coordinate system, and realize the expansion of the field of view; the simultaneous measurement of the left part and the right part is realized, the data are not needed to be spliced after being respectively measured like the traditional method, and the error accumulation is reduced.
Each step will be described in detail as follows:
s10, constructing a binocular system, wherein the binocular system comprises a first camera and a second camera with opposite view field directions, and a plane mirror is arranged in the view field range of the second camera, so that a virtual camera corresponding to the mirror image of the second camera in the plane mirror and the first camera form a new binocular system with overlapped view fields;
for example, as shown in fig. 2, the two cameras are shown as a schematic diagram of a binocular system, the first camera C1 and the second camera C2 are located in opposite directions of the fields of view, and the optical axes are approximately 180 °, that is, the fields of view do not overlap, so that the two cameras cannot shoot the same calibration target at the same time, and therefore cannot calibrate the coordinate system. In this embodiment, a plane mirror is placed in the camera view field range of the second camera C2, and according to the principle of specular reflection, the virtual camera V2 and the first camera C1 of the second camera C2 form a new binocular system with overlapping view fields, so that according to the target, the posture of the plane mirror is adjusted, so that the first camera C1 and the second camera C2 system without overlapping view fields are converted into the first camera C1 and the virtual camera V2 system with overlapping view fields, and thus, the calibration unification of the first camera C1 and the second camera C2 can be completed by setting the camera coordinate system of the plane mirror coordinate system and the virtual camera V2 as an intermediate coordinate system, and the global calibration of the camera without overlapping view fields can be realized.
S20, calculating a first conversion relation between the second camera and the virtual camera;
wherein, a coordinate system is established:a coordinate system representing the second camera C2;OXYZrepresenting the coordinate system of the plane mirror; />A coordinate system representing the virtual camera V2; />By passing throughOXYZRotation about the y-axis results, representing the other side of the mirror. />Representing the second camera C2 and its virtual camera V2Is a conversion relation of (a); />Representing coordinatesTo the point ofOXYZIs a conversion relation of (a); />Representing the slave coordinates->To virtual camera coordinatesIs a conversion relation of (a); />The conversion relationship of the second camera C2 to the virtual camera V2 is represented.
And taking the plane mirror coordinate system as a bridge, and constructing a conversion channel between the second camera C2 and the virtual camera V2. Therefore, the conversion relationship between the second camera C2 and its virtual camera V2 is calculated in three steps. As shown in fig. 3, includes:
s201, calculating a fourth conversion relation between the second camera and the plane mirror;
s203, calculating a fifth conversion relation between the virtual camera and the plane mirror;
s205, calculating a first conversion relation between the second camera and the virtual camera based on the fourth conversion relation and the fifth conversion relation;
wherein, S201, a fourth conversion relation between the second camera and the plane mirror is calculated:
in order to establish a three-dimensional space coordinate system of an object with a plane mirror serving as a space reference-free basis, a checkerboard can be attached to the plane mirror, so that the coordinate system of the characteristic points on the checkerboard is the plane mirror coordinate system. The calibration process can be solved by using a camera calibration tool box in Matlab, so as to obtain a second camera C2 and a plane mirrorMConversion relation between。
Euler angle is a mechanism that includes three rotations, pitch, roll and yaw, that is, rotation about the z-axis, about the y-axis, about the x-axis, respectively, and rotation of the three is independent of each other. The order of positioning Euler angles is generally as followsThen the rotation matrix in three dimensions can be represented by the product of the three. And the product of the rotation matrix is directly expressed in the form of product without the result of specific calculation, because the product is completed by a computer conventional in the art in real application. In this embodiment, euler angles are used to describe the plane mirror in the camera coordinate system +.>The pose state of the model (a). Let->Is a plane mirrorMAnd the positive direction of each angle rotates counterclockwise in the positive direction of its axis.
Wherein the fourth conversion relationExpressed as:
，
wherein ,is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Is used for the rotation matrix of the (c),
represented as
，Is the rotary Euler angle of the plane mirror;
，
wherein ,is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Translation matrix of>Is the translation distance of the second camera in the X-axis, or->Is the translation distance of the second camera on the Y-axis, or->Is the translational distance of the second camera on the Z axis;
optionally, calculating a second conversion relationship between the virtual camera and the first camera includes:
defining a virtual camera coordinate systemThe non-homogeneous coordinates of the spatial point under the world coordinate system, the camera coordinate system and the virtual camera coordinate system are respectively P,P1 and P2, there is
，
wherein , and />Respectively represent the first camera coordinate system->A rotation matrix and a translation matrix between the two world coordinate systems; /> and />Respectively represent +.>A rotation matrix and a translation matrix between the two world coordinate systems;
then, the second conversion relationship between the virtual camera and the first camera is expressed as:
，
wherein , and />Respectively represent +.>To a virtual camera coordinate systemRotation matrix and translation matrix of>Representing the coordinate system +.>To the inverse of the rotation matrix of the P-point world coordinate system.
S203, calculating a fifth conversion relation between the virtual camera and the plane mirror;
because the plane mirror approximates a plane without thickness in the schematic diagram, but in reality, the plane mirror has a certain thickness, there is also a translational relationship between the coordinate systems on both sides of the plane mirror. Here, the conversion relationship between the coordinate systems of the two surfaces of the plane mirror is expressed by a mathematical model, and the thickness of the plane mirror is ignored in the model calculation, that is, the translation relationship is not considered:
，
，
wherein ,=/>，/>，/>representing the slave coordinates->To plane mirror coordinate systemOXYZIs provided for the translation matrix of (a).
According to the principle of planar mirror imaging, and />Relates to a plane mirrorMSymmetrical, so due to the second camera coordinate system +.>And plane mirror coordinate systemOXYZEuler relation exists between the two virtual camera coordinate systemsAnd coordinates->Euler transformation relation exists between them, then use +.>Respectively indicate winding->Shaft(s)>Shaft and->Axis-to-virtual Camera coordinate System->And then the rotation Euler angle of (2) is converted into:
,/>,/>，
wherein the fifth conversion relation is a plane mirror coordinate systemOXYZCoordinate system with virtual cameraThe conversion relation between, i.e.)>，
wherein ,，/>=/>，/>，
is a plane mirror coordinate systemOXYZTo the virtual camera coordinate system->Rotation matrix of>For a translation matrix between the virtual camera and the plane mirror, < >>、/>Respectively represent the coordinates of the plane mirror->To the virtual camera coordinate system->A rotation matrix and a translation matrix of the same; />By passing throughOXYZThe rotation around the Y axis is obtained and represents the other side of the plane mirror; />Is the translation distance of the virtual camera on the X-axis, or->Is the translation distance of the virtual camera on the Y-axis, or->Is the translation distance of the virtual camera in the Z-axis.
S205, calculating a first conversion relationship between the second camera and the virtual camera based on the fourth conversion relationship and the fifth conversion relationship.
The second camera C2 and its virtual camera V2 have been obtained separately from the plane mirror coordinate systemTherefore the coordinates +.>As an intermediate matrix, the conversion relationship of the virtual camera and the second camera is as follows:
，
wherein ,for the second camera coordinate system->To the virtual camera coordinate system->Rotation matrix of>For the second camera coordinate system->To the virtual camera coordinate system->Translation matrix of>For the second camera coordinate system->To plane mirror coordinate systemOXYZIs used to rotate the matrix.
As an embodiment of the inventionThe improvement of one step also needs to calculate a second conversion relation between the virtual camera and the first camera, according to the perspective principle, the virtual camera V2 and the first camera C1 can be regarded as a common binocular camera system with overlapped fields of view, a checkerboard target is placed in a common field of view, and the external parameter calibration of the virtual camera V2 and the first camera C1 can be completed by using a traditional binocular camera calibration method. At this time, a virtual camera coordinate system is definedThe non-homogeneous coordinates of the spatial point under the world coordinate system, the camera coordinate system and the virtual camera coordinate system are respectively P,P1andP2the following steps are:
，
wherein , and />Respectively represent the first camera coordinate system->A rotation matrix and a translation matrix between the two world coordinate systems; /> and />Respectively represent +.>A rotation matrix and a translation matrix between the two world coordinate systems;
then, the second conversion relationship between the virtual camera and the first camera is expressed as:
，
wherein , and />Respectively represent +.>To a virtual camera coordinate systemRotation matrix and translation matrix of>Representing the coordinate system +.>To the inverse of the rotation matrix of the P-point world coordinate system.
In this embodiment, according to the mirror projection principle, the perspective projection of any point P on the checkerboard target to the virtual camera V2 is equal to the virtual pointP2Perspective projection of the second camera C2, while the rotation matrix and translation matrix of the point P with respect to the virtual camera V2 are equal to the virtual pointP2Rotation matrix and translation matrix with respect to the second camera C2:
，
next, with the virtual camera V2 as an intermediate coordinate, a conversion relationship between the first camera C1 and the second camera C2 can be obtained:
，
，
the simplification can be obtained:
，
wherein , and />Respectively represent +.>To a second camera coordinate systemA rotation matrix and a translation matrix of (a); /> and />Respectively represent +.>Mirror coordinate system>To the first camera coordinate system->A rotation matrix and a translation matrix of (a); /> and />Respectively represent +.>Mirror coordinate system>To a virtual camera coordinate systemA rotation matrix and a translation matrix of (a); /> and />Respectively from the second camera coordinate system +.>To the virtual camera coordinate system->Is a rotation matrix and a translation matrix of the same.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (5)
1. The camera parameter calibration method based on the plane mirror and without overlapping view fields is characterized by comprising the following steps:
s10, constructing a binocular system, wherein the binocular system comprises a first camera and a second camera with opposite view field directions, and a plane mirror is arranged in the view field range of the second camera, so that a virtual camera corresponding to the mirror image of the second camera in the plane mirror and the first camera form a new binocular system with overlapped view fields;
s20, calculating a first conversion relation between the second camera and the virtual camera;
s30, calculating a second conversion relation between the virtual camera and the first camera;
s40, calculating a third conversion relation between the first camera and the second camera based on the first conversion relation and the second conversion relation so as to realize camera parameter calibration of non-overlapping fields of view;
wherein calculating the first conversion relationship between the second camera and the virtual camera comprises:
calculating a fourth conversion relation between the second camera and the plane mirror;
calculating a fifth conversion relation between the virtual camera and the plane mirror;
calculating a first conversion relationship between the second camera and the virtual camera based on the fourth conversion relationship and the fifth conversion relationship, the first conversion relationship being as follows:
，
wherein ,for the second camera coordinate system->To the virtual camera coordinate system->Rotation matrix of>For the second camera coordinate system->To the virtual camera coordinate system->Is a translation matrix of (a); />For the second camera coordinate system->To plane mirror coordinate systemOXYZIs a rotation matrix of (a);
is flatMirror coordinate systemOXYZTo the virtual camera coordinate system->Rotation matrix of>Is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Is a rotation matrix of (a);
is a plane mirror coordinate systemOXYZTo the virtual camera coordinate system->Translation matrix of>Is a plane mirror coordinate systemOXYZTo the second camera coordinate system->Is provided for the translation matrix of (a).
2. The method for calibrating camera parameters based on planar mirror and having no overlapping fields of view as set forth in claim 1, wherein said fourth transformation relationship is a planar mirror coordinate systemOXYZWith a second camera coordinate systemThe conversion relation between, i.e.)>, wherein ,
，
represented as
，Is the rotary Euler angle of the plane mirror;
，
wherein ,is the translation distance of the second camera in the X-axis, or->Is the translation distance of the second camera on the Y-axis, or->Is the translational distance of the second camera in the Z-axis.
3. The method for calibrating camera parameters based on planar mirror and having no overlapping fields of view as set forth in claim 1, wherein said fifth transformation relationship is a planar mirror coordinate systemOXYZCoordinate system with virtual cameraConversion relation between, i.e，
wherein ,，/>=/>，/>，
、/>respectively represent the coordinates of the plane mirror->To the virtual camera coordinate system->A rotation matrix and a translation matrix of the same; />By passing throughOXYZThe rotation around the Y axis is obtained and represents the other side of the plane mirror; />Is the translation distance of the virtual camera on the X-axis, or->Is the translation distance of the virtual camera on the Y-axis, or->Is the translation distance of the virtual camera in the Z-axis.
4. The planar mirror based non-overlapping field of view camera parameter calibration method of claim 1, wherein calculating a second conversion relationship between the virtual camera and the first camera comprises:
defining a virtual camera coordinate systemThe non-homogeneous coordinates of the spatial point under the world coordinate system, the camera coordinate system and the virtual camera coordinate system are respectively P,P1 and P2, there is
，
wherein , and />Respectively represent the first camera coordinate system->A rotation matrix and a translation matrix between the two world coordinate systems; /> and />Respectively represent +.>A rotation matrix and a translation matrix between the two world coordinate systems;
then, the second conversion relationship between the virtual camera and the first camera is expressed as:
，
wherein , and />Respectively represent +.>To a virtual camera coordinate systemRotation matrix and translation matrix of>Representing the coordinate system +.>To the inverse of the rotation matrix of the P-point world coordinate system.
5. The planar mirror based non-overlapping field of view camera parameter calibration method of claim 1, wherein calculating a third conversion relationship between the first camera and the second camera based on the first conversion relationship and the second conversion relationship comprises:
taking the virtual camera as an intermediate coordinate, obtaining a third conversion relation between the first camera and the second camera as follows:
，
wherein , and />Respectively represent +.>To a second camera coordinate systemA rotation matrix and a translation matrix of (a); /> and />Respectively from a first camera coordinate systemMirror coordinate system>To the first camera coordinate system->A rotation matrix and a translation matrix of (a); /> and />Respectively represent +.>Is a mirror image of the coordinate system of (2)To the virtual camera coordinate system->A rotation matrix and a translation matrix of (a); /> and />Respectively from the second camera coordinate system +.>To the virtual camera coordinate system->Is a rotation matrix and a translation matrix of the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311151609.4A CN116883517B (en) | 2023-09-07 | 2023-09-07 | Camera parameter calibration method without overlapping view fields based on plane mirror |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311151609.4A CN116883517B (en) | 2023-09-07 | 2023-09-07 | Camera parameter calibration method without overlapping view fields based on plane mirror |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116883517A true CN116883517A (en) | 2023-10-13 |
| CN116883517B CN116883517B (en) | 2023-11-10 |
Family
ID=88255522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311151609.4A Active CN116883517B (en) | 2023-09-07 | 2023-09-07 | Camera parameter calibration method without overlapping view fields based on plane mirror |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116883517B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107529371B (en) * | 2014-11-26 | 2017-03-29 | 上海新跃仪表厂 | The non-cooperation binocular measuring system of super close distance and its measuring method |
| CN109215086A (en) * | 2018-08-24 | 2019-01-15 | 深圳市寒武纪智能科技有限公司 | Camera extrinsic scaling method, equipment and system |
| CN110248179A (en) * | 2019-04-04 | 2019-09-17 | 复旦大学 | Camera pupil aberration correcting method based on light field coding |
| CN110827360A (en) * | 2019-10-31 | 2020-02-21 | 华中科技大学 | Photometric stereo measurement system and method for calibrating light source direction thereof |
| CN112258586A (en) * | 2020-10-16 | 2021-01-22 | 中国石油大学(华东) | Calibration method for stereoscopic vision model parameters of single plane mirror |
| CN113223135A (en) * | 2021-04-15 | 2021-08-06 | 中山大学 | Three-dimensional reconstruction device and method based on special composite plane mirror virtual image imaging |
| CN114111637A (en) * | 2021-11-25 | 2022-03-01 | 天津工业大学 | Stripe structured light three-dimensional reconstruction method based on virtual dual-purpose |
| CN115560695A (en) * | 2022-05-21 | 2023-01-03 | 华东交通大学 | Global calibration method for linear structured light vision sensor of plane mirror without overlapping view field |
| US20230009683A1 (en) * | 2019-12-05 | 2023-01-12 | Airbus Defence And Space Sas | Simulation sighting binoculars, and simulation system and methods |
| WO2023000595A1 (en) * | 2021-07-19 | 2023-01-26 | 中国科学院深圳先进技术研究院 | Curved screen-based phase deflection measurement method and system, and terminal |
-
2023
- 2023-09-07 CN CN202311151609.4A patent/CN116883517B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107529371B (en) * | 2014-11-26 | 2017-03-29 | 上海新跃仪表厂 | The non-cooperation binocular measuring system of super close distance and its measuring method |
| CN109215086A (en) * | 2018-08-24 | 2019-01-15 | 深圳市寒武纪智能科技有限公司 | Camera extrinsic scaling method, equipment and system |
| CN110248179A (en) * | 2019-04-04 | 2019-09-17 | 复旦大学 | Camera pupil aberration correcting method based on light field coding |
| CN110827360A (en) * | 2019-10-31 | 2020-02-21 | 华中科技大学 | Photometric stereo measurement system and method for calibrating light source direction thereof |
| US20230009683A1 (en) * | 2019-12-05 | 2023-01-12 | Airbus Defence And Space Sas | Simulation sighting binoculars, and simulation system and methods |
| CN112258586A (en) * | 2020-10-16 | 2021-01-22 | 中国石油大学(华东) | Calibration method for stereoscopic vision model parameters of single plane mirror |
| CN113223135A (en) * | 2021-04-15 | 2021-08-06 | 中山大学 | Three-dimensional reconstruction device and method based on special composite plane mirror virtual image imaging |
| WO2023000595A1 (en) * | 2021-07-19 | 2023-01-26 | 中国科学院深圳先进技术研究院 | Curved screen-based phase deflection measurement method and system, and terminal |
| CN114111637A (en) * | 2021-11-25 | 2022-03-01 | 天津工业大学 | Stripe structured light three-dimensional reconstruction method based on virtual dual-purpose |
| CN115560695A (en) * | 2022-05-21 | 2023-01-03 | 华东交通大学 | Global calibration method for linear structured light vision sensor of plane mirror without overlapping view field |
Non-Patent Citations (7)
| Title |
|---|
| PIERRE LÉBRALY等: "Flexible extrinsic calibration of non-overlapping cameras using a planar mirror: Application to vision-based robotics", 2010 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS * |
| RAM KRISHAN KUMAR等: "Simple calibration of non-overlapping cameras with a mirror", 2008 IEEE CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION * |
| 吴子伟: "非重叠视场中的双目测量系统标定方法研究", 中国优秀硕士学位论文全文数据库 * |
| 吴恩启;田士强;徐世鹏;蒋猛;: "单相机立体视觉测量技术的研究", 光学技术, no. 01 * |
| 孟祥翔;刘伟奇;张大亮;姜国华;朱秀庆;杨建明;: "双自由曲面大视场头盔显示光学系统设计", 红外与激光工程, no. 04 * |
| 宋丫;柴兴华;周富强;: "单摄像机全向立体视觉传感器的结构设计", 光学学报, no. 06 * |
| 张文卿: "无重叠视场视觉测量系统与标定方法", 机械设计与研究 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116883517B (en) | 2023-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109859275B (en) | Monocular vision hand-eye calibration method of rehabilitation mechanical arm based on S-R-S structure | |
| CN107738254B (en) | Conversion calibration method and system for mechanical arm coordinate system | |
| CN110695993B (en) | Synchronous measurement method, system and device for flexible mechanical arm | |
| Zhan et al. | Hand–eye calibration and positioning for a robot drilling system | |
| JP5337805B2 (en) | Local positioning system and method | |
| CN111415391B (en) | External azimuth parameter calibration method for multi-camera by adopting mutual shooting method | |
| US10310054B2 (en) | Relative object localization process for local positioning system | |
| CN111801198B (en) | Hand-eye calibration method, system and computer storage medium | |
| US20120065928A1 (en) | Optical measurement system | |
| Zhang et al. | A universal and flexible theodolite-camera system for making accurate measurements over large volumes | |
| Li | Camera calibration of a head-eye system for active vision | |
| Xie et al. | Calibration of 6-DOF industrial robots based on line structured light | |
| Jiang et al. | A measurement method for robot peg-in-hole prealignment based on combined two-level visual sensors | |
| JP2010172986A (en) | Robot vision system and automatic calibration method | |
| CN109087355B (en) | Monocular camera pose measuring device and method based on iterative updating | |
| JP2011123051A (en) | Three-dimensional measurement method | |
| CN113744340A (en) | Calibrating cameras with non-central camera models of axial viewpoint offset and computing point projections | |
| CN110686650B (en) | Monocular vision pose measuring method based on point characteristics | |
| Xu et al. | A calibration method for non-overlapping cameras based on mirrored absolute phase target | |
| Liu et al. | A high-accuracy pose measurement system for robotic automated assembly in large-scale space | |
| CN116681772A (en) | Multi-camera online calibration method under non-common view | |
| CN111915685A (en) | Zoom camera calibration method | |
| KR102152217B1 (en) | Jig for matching coordinates of VR and AR devices and method for sharing physical space by using the jig | |
| CN112857328B (en) | Calibration-free photogrammetry method | |
| CN111220118B (en) | Laser range finder based on visual inertial navigation system and range finding method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |