CN110060305B - High-precision simplified linear array camera calibration method - Google Patents
High-precision simplified linear array camera calibration method Download PDFInfo
- Publication number
- CN110060305B CN110060305B CN201910294845.9A CN201910294845A CN110060305B CN 110060305 B CN110060305 B CN 110060305B CN 201910294845 A CN201910294845 A CN 201910294845A CN 110060305 B CN110060305 B CN 110060305B
- Authority
- CN
- China
- Prior art keywords
- matrix
- array camera
- parameter matrix
- camera
- linear array
- 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.)
- Active
Links
Images
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
Landscapes
- Engineering & Computer Science (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Image Processing (AREA)
- Studio Devices (AREA)
Abstract
A high-precision simplified linear array camera calibration method is disclosed, in which the internal relation r in the rotary matrix of the linear array camera imaging model is derived 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 0, and A ‑T A ‑1 Forming a symmetric matrix, forming an overrun equation
More than 2H matrixes can be obtained by selecting coordinates (X, Y) of a target point to coordinates (u) of an imaging point in more than 2 calibration plates with different angles or different distances, an equation is established, and a parameter B is solved 11 ，B 12 ，B 22 And then obtaining the internal and external parameters of the linear array camera. The method has simple system and less unknown parameter calculation, and has important significance and practical value for the application of the linear array camera calibration.
Description
Technical Field
The invention belongs to the field of camera calibration, and particularly relates to a high-precision simplified linear array camera calibration method.
Background
The calibration of the camera is a very critical link for determining the calibration of the space camera, and the accuracy of the calibration result and the stability of the algorithm directly influence the accuracy of the result generated by the operation of the camera. Therefore, it is the key point of camera calibration to improve the camera calibration precision.
Because the linear array camera can only image one line in each imaging, and the linear array imaging model is different from the traditional area array camera imaging model, the internal and external parameter calculation method suitable for the area array camera is not suitable for the linear array camera. The internal and external parameter constraint equation of the existing linear array camera is complex, so that a simple and effective constraint equation is established according to an imaging model of the linear array camera, and the linear array camera has practical research value and practical application value.
When 3 homography matrixes H are obtained by the method for calibrating the internal and external parameters of the single-line-array camera, the space coordinates of characteristic points in a calibration plate in a world coordinate system need to be known, the current commonly used calibration plate is a plane calibration plate, the (X, Y) in the space coordinates is easy to determine, but the coordinates in the Z direction can be obtained by using precision positioning equipment; or a three-dimensional calibration object is used, but the calibration is complex to manufacture and cannot easily meet the precision requirement.
According to the invention, through theoretical derivation, the precision requirement on the characteristic point in the Z direction is abandoned, the same high-precision calibration effect can be achieved by using the planar calibration plate, the requirement on a calibration object is low, and the calibration process is convenient. How to abandon the accuracy requirement of the characteristic point in the Z direction and not influence the calibrated high accuracy is a technical problem to be solved at present.
Disclosure of Invention
In order to solve the technical problems, the invention provides a high-precision simplified linear array camera calibration method, which simplifies the original calibration method, and only utilizes easily determined space coordinates to complete the linear array camera calibration without influencing the calibration precision.
In order to realize the technical purpose, the adopted technical scheme is as follows: a high-precision simplified linear array camera calibration method comprises the following steps:
step 1, deducing a linear array camera imaging model according to an area array camera imaging model to obtain a homography matrix H model
Step 2, deducing an internal parameter matrix A and an external parameter matrix [ r ] of the line-scan camera according to the imaging model of the line-scan camera 1 r 2 t]；
Step 3, rotating the parameter matrix r according to the external parameter matrix 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 1 If 0, the parameters and homography in the internal parameter A are derivedLinking of parameters in the property matrix H
Step 4, calculate A -T A -1 And is provided with B 11 、B 12 、B 22 Alternative A -T A -1 Parameters in the matrix, substitution
To obtain
Step 5, selecting more than 2 coordinates (X, Y) from target points of calibration plates with different angles or different distances to coordinates (u) of imaging points, calculating to obtain more than 2H matrixes, and substituting the H matrixes into the H matrixes
Formula (I) using least squares to obtain B 11 、B 12 、B 22 A value of (d);
step 6, according to B 11 、B 12 、B 22 Calculating an internal parameter matrix A, then taking an H matrix obtained in the fifth step according to the internal parameter matrix A, and calculating an external parameter matrix [ r 1 r 2 t]。
The method for constructing the homography matrix H model in the step 1 comprises the following steps:
step 1.1, area-array camera imaging model
s is any real number;
step 1.2, imaging one line each time by the linear array camera, and obtaining the line image according to the area array camera imaging model
Step 1.3, the imaging model in the step 1.2 is reversely pushed again, and the imaging model can be obtained
Step 1.4, assuming z is 0, so
The internal parameter matrix A and the external parameter matrix [ r ] in the step 2 of the invention 1 r 2 t]The derivation method comprises the following steps:
step 2.1, the imaging model of the area-array camera including internal and external parameters
m＝[u v 1] T ，M＝[x y z 1] T
Step 2.2, because only one line can be imaged in each imaging of the line camera, according to the imaging model of the area camera, if z is equal to 0, the method can obtain
Step 2.3, assuming z is 0, so
In step 3 of the present invention
The derivation method comprises the following steps:
step 3.1, because [ h ] 1 h 2 h 4 ]＝sA[r 1 r 2 t]Is obtained by
h 1 ＝sAr 1 Or r 1 ＝λA -1 h 1
h 2 ＝sAr 2 Or r 2 ＝λA -1 h 2
h 4 sAt or λ a -1 h 4
Step 3.2, because r 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 When the value is equal to 0, r is 1 ，r 2 Substituted to obtain
In step 4 of the present invention
The derivation method comprises the following steps:
step 4.1, calculate A -T A -1
Step 4.2, setting B 11 、B 12 、B 22 Three parameter replacement A -T A -1 Parameters in the matrix;
step 4.3, substituting B into
To obtain
The internal parameter matrix A and the external parameter matrix [ r ] in step 6 of the invention 1 r 2 t]The calculation method of (2) is as follows:
step 6.1 Equipment
By
To obtain
c u ＝-B 12 /B 11
Step 6.2, mixing f u ，c u Substituting the A into the A to obtain an internal parameter matrix A;
step 6.3, arbitrarily take the H matrix obtained in step 5, and substitute A, H into λ ═ 1/s ═ 1/| | | a -1 h 1 ||＝1/||A -1 h 2 | can be given as λ, further substituted into r 1 ＝λA -1 h 1 ，r 2 ＝λA -1 h 2 ，t＝λA -1 h 4 The extrinsic parameter matrix [ r ] is obtained 1 r 2 t]。
The beneficial effects of the invention are: the internal relation r in the linear array camera imaging model rotation matrix proposed by the invention 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 0, and A -T A -1 Forming a symmetric matrix, forming an overrun equation
More than 2 coordinates (X, Y) of the target point to the imaging point in more than 2 calibration plates with different angles or different distances are selectedH matrix, establishing equation and solving parameter B 11 ，B 12 ，B 22 And then obtaining the internal and external parameters of the linear array camera. The method has simple system and less unknown parameter calculation, and has important significance and practical value for the application of the linear array camera calibration.
Drawings
FIG. 1 is a schematic flow diagram of the process of the present invention.
Detailed Description
For a better understanding of the technical aspects of the present invention, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in FIG. 1, the present invention is based on the rotation parameter matrix r in the extrinsic parameter matrix 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 And (3) deducing the relation between the parameters in the internal parameters and the parameters in the homography matrix, establishing a constraint equation, solving the homography matrix from a plurality of target points to an imaging point by using coordinates (X, Y) of the target points of the calibration plate to the imaging point, substituting the homography matrix into the constraint equation, and further calculating the internal and external parameters of the linear array camera.
The invention is implemented as follows:
a high-precision simplified linear array camera calibration method comprises the following steps:
step 1, deducing a linear array camera imaging model according to an area array camera imaging model to obtain a homography matrix H model
Step 1.1, area-array camera imaging model
s is any real number.
Step 1.2, imaging one line each time by the linear array camera, and obtaining the line image according to the area array camera imaging model
Step 1.3, the imaging model in the step 1.2 is reversely pushed again, and the method can be obtained
Step 1.4, assuming z is 0, so
Step 2, deducing an internal parameter matrix A and an external parameter matrix [ r ] of the line-scan camera according to the imaging model of the line-scan camera 1 r 2 t]；
Step 2.1, the imaging model of the area-array camera including internal and external parameters
m＝[u v 1] T ，M＝[x y z 1] T
Step 2.2, because only one line can be imaged in each imaging of the line camera, according to the imaging model of the area camera, if z is equal to 0, the method can obtain
Step 2.3, assuming z is 0, so
Step 3, rotating the parameter matrix r according to the external parameter matrix 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 0 deducing the relation between the parameters in the internal parameter A and the parameters in the homography matrix H
Step 3.1, because [ h ] 1 h 2 h 4 ]＝sA[r 1 r 2 t]Obtained by
h 1 ＝sAr 1 Or r 1 ＝λA -1 h 1
h 2 ＝sAr 2 Or r 2 ＝λA -1 h 2
h 4 sAt or λ a -1 h 4
Step 3.2, because r 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 When the value is equal to 0, r is 1 ，r 2 Substituted to obtain
Step 4, calculating A -T A -1 And is provided with B 11 ，B 12 ，B 22 Alternative A -T A -1 Parameters in the matrix, substitution
To obtain
Step 4.1, calculate A -T A -1
Step 4.2, settingB 11 、B 12 、B 22 Three parameter replacement A -T A -1 Parameters in the matrix;
step 4.3, substituting B into
To obtain
Step 5, selecting more than 2 coordinates (X, Y) from target points of calibration plates with different angles or different distances to coordinates (u) of imaging points, calculating to obtain more than 2H matrixes, and substituting the H matrixes into the H matrixes
Formula (I) using least squares to obtain B 11 、B 12 、B 22 The value of (c).
Step 6 according to B 11 ，B 12 ，B 22 Calculating an internal parameter matrix A, then taking the internal parameter matrix A, taking an obtained H matrix, and calculating an external parameter matrix [ r [ r ] ] 1 r 2 t]；
Step 6.1 Equipment
To obtain
c u ＝-B 12 /B 11
Step 6.2, f u 、c u Substituting the A into the A to obtain an internal parameter matrix A;
step 6.3, taking the H matrix obtained in step 5, and substituting A, H into λ ═ 1/s ═ 1/| | | a -1 h 1 ||＝1/||A -1 h 2 | can be given as λ, further substituted into r 1 ＝λA -1 h 1 ，r 2 ＝λA -1 h 2 ，t＝λA -1 h 4 The extrinsic parameter matrix [ r ] can be obtained 1 r 2 t]。
Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present invention, which is defined in the claims.
Claims (6)
1. A high-precision simplified linear array camera calibration method is characterized by comprising the following steps:
step 1, deducing a linear array camera imaging model according to an area array camera imaging model to obtain a homography matrix H model
Step 2, deducing an internal parameter matrix A and an external parameter matrix [ r ] of the line-scan camera according to the imaging model of the line-scan camera 1 r 2 t]；
Step 3, rotating the parameter matrix r according to the external parameter matrix 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 And (5) deducing the relation between the parameters in the internal parameter A and the parameters in the homography matrix H as 0
Step 4, calculate A -T A -1 And is provided with B 11 、B 12 、B 22 Alternative A -T A -1 Parameters in the matrixSubstitution into
To obtain
Step 5, selecting more than 2 pairs of coordinates (X, Y) of target points of calibration plates with different angles or different distances to coordinates (u) of imaging points, calculating to obtain more than 2H matrixes, and substituting the H matrixes into the H matrixes
Formula (B) using least squares 11 、B 12 、B 22 A value of (d);
step 6, according to B 11 、B 12 、B 22 Calculating an internal parameter matrix A, then according to the internal parameter matrix A, taking the H matrix obtained in the fifth step, and calculating an external parameter matrix [ r 1 r 2 t]。
2. A high-precision simplified line camera calibration method as set forth in claim 1, characterized in that: the method for forming the homography matrix H model in the step 1 comprises the following steps:
step 1.1, area-array camera imaging model
s is any real number;
step 1.2, imaging one line each time by the linear array camera, and obtaining the line image according to the area array camera imaging model
Step 1.3, the imaging model in the step 1.2 is reversely pushed again, and the imaging model can be obtained
Step 1.4, assuming z is 0, so
3. A high-precision simplified line camera calibration method as set forth in claim 1, characterized in that: the internal parameter matrix A and the external parameter matrix [ r ] in the step 2 1 r 2 t]The derivation method comprises the following steps:
step 2.1, the imaging model of the area-array camera including internal and external parameters
m＝[u v 1] T ，M＝[x y z 1] T
Step 2.2, because only one line can be imaged in each imaging of the line camera, according to the imaging model of the area camera, if z is equal to 0, the method can obtain
Step 2.3, assume z is 0, therefore
4. A high-precision simplified line camera calibration method as defined in claim 1, wherein: in the step 3
The derivation method comprises the following steps:
step 3.1, because [ h ] 1 h 2 h 4 ]＝sA[r 1 r 2 t]Obtained by
h 1 ＝sAr 1 Or r 1 ＝λA -1 h 1
h 2 ＝sAr 2 Or r 2 ＝λA -1 h 2
h 4 sAt or λ a -1 h 4
Step 3.2, because r 1 T r 1 ＝r 2 T r 2 1 and r 1 T r 2 When the value is equal to 0, r is 1 ，r 2 Substituted to obtain
5. A high-precision simplified line camera calibration method as set forth in claim 1, characterized in that: in the step 4
The derivation method comprises the following steps:
step 4.1, calculate A -T A -1
Step 4.2, setting B 11 、B 12 、B 22 Three parameter replacement A -T A -1 Parameters in the matrix;
step 4.3, substituting B into
To obtain
6. A high-precision simplified line camera calibration method as defined in claim 1, wherein: the internal parameter matrix A and the external parameter matrix [ r ] in the step 6 1 r 2 t]The calculation method of (2) is as follows:
step 6.1 Equipment
By
To obtain
c u ＝-B 12 /B 11
Step 6.2, f u ，c u Substituting the A into the A to obtain an internal parameter matrix A;
step 6.3, arbitrarily take the H matrix obtained in step 5, and substitute A, H into λ ═ 1/s ═ 1/| | | a -1 h 1 ||＝1/||A -1 h 2 | can be given as λ, further substituted into r 1 ＝λA -1 h 1 ，r 2 ＝λA -1 h 2 ，t＝λA -1 h 4 Is obtained byExtrinsic parameter matrix [ r ] 1 r 2 t]。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910294845.9A CN110060305B (en) | 2019-04-12 | 2019-04-12 | High-precision simplified linear array camera calibration method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910294845.9A CN110060305B (en) | 2019-04-12 | 2019-04-12 | High-precision simplified linear array camera calibration method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110060305A CN110060305A (en) | 2019-07-26 |
| CN110060305B true CN110060305B (en) | 2022-09-30 |
Family
ID=67318873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910294845.9A Active CN110060305B (en) | 2019-04-12 | 2019-04-12 | High-precision simplified linear array camera calibration method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110060305B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104123725A (en) * | 2014-07-14 | 2014-10-29 | 河南科技大学 | Homography matrix H computing method of single line array camera |
| CN104182969A (en) * | 2014-08-08 | 2014-12-03 | 河南科技大学 | Internal and external parameter calibration method of single-scanline camera |
| CN104958061A (en) * | 2015-07-28 | 2015-10-07 | 北京信息科技大学 | Fundus OCT imaging method utilizing three-dimensional imaging of binocular stereo vision and system thereof |
| WO2018228013A1 (en) * | 2017-06-12 | 2018-12-20 | 北京航空航天大学 | Front coated plane mirror-based structured light parameter calibration device and method |
-
2019
- 2019-04-12 CN CN201910294845.9A patent/CN110060305B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104123725A (en) * | 2014-07-14 | 2014-10-29 | 河南科技大学 | Homography matrix H computing method of single line array camera |
| CN104182969A (en) * | 2014-08-08 | 2014-12-03 | 河南科技大学 | Internal and external parameter calibration method of single-scanline camera |
| CN104958061A (en) * | 2015-07-28 | 2015-10-07 | 北京信息科技大学 | Fundus OCT imaging method utilizing three-dimensional imaging of binocular stereo vision and system thereof |
| WO2018228013A1 (en) * | 2017-06-12 | 2018-12-20 | 北京航空航天大学 | Front coated plane mirror-based structured light parameter calibration device and method |
Non-Patent Citations (2)
| Title |
|---|
| 二轴转台测角法用于线阵相机几何参数标定;周梓聪等;《中国图象图形学报》;20170916(第09期);全文 * |
| 线扫描相机标定及畸变矫正方法;朱瑶等;《航天返回与遥感》;20171215(第06期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110060305A (en) | 2019-07-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103530880B (en) | Based on the camera marking method of projection Gaussian network pattern | |
| CN111784778B (en) | Binocular camera external parameter calibration method and system based on linear solving and nonlinear optimization | |
| CN107367229B (en) | Free binocular stereo vision rotating shaft parameter calibration method | |
| CN110285827B (en) | Distance-constrained photogrammetry high-precision target positioning method | |
| CN103743352B (en) | A kind of 3 D deformation measuring method based on polyphaser coupling | |
| WO2022160760A1 (en) | Calibration method and apparatus for multiple stereo cameras | |
| CN108053450A (en) | A kind of high-precision binocular camera scaling method based on multiple constraint | |
| CN107886547B (en) | Fisheye camera calibration method and system | |
| CN103983963B (en) | A kind of autoegistration method of multistation ground laser radar data | |
| CN107507246A (en) | A kind of camera marking method based on improvement distortion model | |
| CN111369607B (en) | Prefabricated part assembling and matching method based on picture analysis | |
| WO2020199439A1 (en) | Single- and dual-camera hybrid measurement-based three-dimensional point cloud computing method | |
| CN109272555B (en) | External parameter obtaining and calibrating method for RGB-D camera | |
| CN110398208A (en) | Big data deformation monitoring method based on photographic measuring apparatus system | |
| CN104048649B (en) | A kind of multi-view images and the rapid registering method of threedimensional model | |
| CN105910584B (en) | Large scale dynamic photogrammtry system it is high-precision fixed to and orientation accuracy evaluation method | |
| CN112381862B (en) | Full-automatic registration method and device for CAD (computer-aided design) model and triangular mesh | |
| CN105139411A (en) | Large visual field camera calibration method based on four sets of collinear constraint calibration rulers | |
| CN113450416B (en) | TCSC method applied to three-dimensional calibration of three-dimensional camera | |
| CN105488535B (en) | A kind of three-dimensional point cloud matching process | |
| CN109883399A (en) | One kind is based on the photogrammetric alternately approach algorithm of the modified overlapping multi-disc of focal length | |
| CN110060305B (en) | High-precision simplified linear array camera calibration method | |
| CN107504959B (en) | Method for measuring house wall base outline by utilizing inclined aerial image | |
| CN101894369B (en) | Real-time method for computing focal length of camera from image sequence | |
| CN113409395B (en) | High-precision detection and positioning method for catheter end |
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 | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20190726 Assignee: Luoyang Lingxiang computer technology development Co.,Ltd. Assignor: HENAN University OF SCIENCE AND TECHNOLOGY Contract record no.: X2023980038641 Denomination of invention: A high-precision simplified calibration method for linear array cameras Granted publication date: 20220930 License type: Common License Record date: 20230727 |
|
| EE01 | Entry into force of recordation of patent licensing contract |