CN104123725B - A kind of computational methods of single line array camera homography matrix H - Google Patents
A kind of computational methods of single line array camera homography matrix H Download PDFInfo
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- CN104123725B CN104123725B CN201410332592.7A CN201410332592A CN104123725B CN 104123725 B CN104123725 B CN 104123725B CN 201410332592 A CN201410332592 A CN 201410332592A CN 104123725 B CN104123725 B CN 104123725B
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Abstract
A kind of computational methods of single line array camera homography matrix H, the method uses Cross ration invariability principle, and the 4 lines scaling boards that the present invention is provided, 4 lines to meet following rule:,,,, with reference to line-scan digital camera imaging characteristicses, (x, y, the z) coordinate on D4 lines can be calculated with Cross ration invariability, and then calculate homography matrix H according to the double ratio of conllinear 4 points of image plane.
Description
Technical field
The invention belongs to camera calibration neighborhood, it is related to single line array camera impact point to the meter of the homography matrix H of imaging point
Calculation method.
Background technology
The demarcation of video camera be to determine the three-dimensional geometry position of space object surface point with its in the picture corresponding points it
Between correlation.It is the geometrical model according to the video camera imaging set up, is sat by the image coordinate and the world of known features point
Mark solves the parameter model of video camera.Camera calibration is unusual the key link, the precision of its calibration result and algorithm it is steady
It is qualitative to directly affect the accuracy that camera operation produces result.Therefore, it is camera calibration to improve camera calibration precision
Emphasis.
A wherein important step is exactly homography matrix H of the impact point to imaging point.Homography matrix H is obtained, is just needed
It is to be understood that coordinate of ground point and imaging point coordinates.Method therefor obtains this two kinds of coordinates of point using scaling board.It is common at present
Punctuate plate has chessboard calibration plate, circular scaling board and equidistant striped scaling board.Chessboard calibration plate can very easily obtain target
The coordinate of point, such as will obtain accurate imaging point coordinates, it is necessary to do relative uniform motion between single line array camera and scaling board, this is just
System complexity is caused to increase.With circular scaling board, if doing relative uniform motion between single line array camera and scaling board
Speed setting is bad, and the circle of the imaging plane for obtaining will deform, it is impossible to effectively calculate the center of circle, so cannot obtain accurately into
Picpointed coordinate.Equidistant striped scaling board can quickly obtain the x-axis or the value of y-axis of impact point and imaging point, but cannot obtain
The value of another reference axis.
To sum up, existing single line array camera impact point, to the computational methods of the homography matrix H of imaging point, is also present at present
Some shortcomings:Relative uniform motion is done between single line array camera and scaling board, speed setting is difficult.Phase is done between camera and scaling board
To non-uniform movement, it is impossible to calculate homography matrix H.
The content of the invention
It is an object of the invention to provide a kind of computational methods of single line array camera homography matrix H, to reach camera and mark
Relative non-uniform movement is done between fixed board, it is also possible to calculate single line array camera homography matrix H.
To achieve the above object, the computational methods of single line array camera homography matrix H of the invention, the method is using special
4 line scaling boards, using the imaging characteristicses and conllinear 4 points of Cross ration invariability of single line array camera, calculating single line array camera list should
Property matrix H.The step of the method, is as follows:
(1)The lines in single line array camera image are extracted with Hough operation methods, in the lines in a capture plane
A line, this journey is intersected with 4 lines in the image of the 4 lines scaling boards for photographing, and takes intersection point for a, b, c and d;
(2)Ask for the double ratio of imaging point a, b, c and d。
(3)The double ratio of imaging point a, b, c impact point A, B, C and D corresponding with d is obtained using Cross ration invariability, and then calculate D points(X, y, z)Coordinate.
(4)D points and D points are imaged point coordinates accordingly and substitute into impact point to the homography matrix H formula of imaging point, can counted
Calculate corresponding H-matrix.
Described step(1)In 4 lines scaling boards, 4 lines meet following rule:,,,,For that can set certainly according to demand.
The step(2)The double ratio of four points a, b, c and d is on cathetus, ac is a and c two
Distance between point.Bc, ad and bd are similarly.
The step(3)Middle Cross ration invariability is
The step(3)Middle calculating D points(X, y, z)The step of coordinate, is as follows:
(1), it is considered to a dummy line D5, it and D1, D2, D3 parallel co-planar, D1, D2, D3 and by D points D5 this four
Parallel lines are A', B', C' and D' with y-axis intersection point.There are Cross ration invariability, Wo Menyou
Therefore,
(2)A, B, C and D can be obtained on four calibration lines of scaling board
Can further obtain:
Because 4 calibration lines of scaling board are coplanar, it is in the z coordinate of this target board space coordinate, being can according to demand certainly
Setting, can obtain D points(X, y, z)Coordinate.
The step(4)The step of middle calculating homography matrix H, is as follows:
(1)By common line-scan digital camera homography formula
Derive outlet list array camera homography formula
It is scale parameter;
Therefore homography matrix H is
(2)By common line-scan digital camera homography formula, according to impact point D(X, y, z)With corresponding imaging point coordinates d(u),
Zero coordinate points of imager coordinate are the summit in da directions, can calculate homography matrix H.The beneficial effects of the invention are as follows:This hair
The computational methods of bright single line array camera homography matrix H, using 4 special line scaling boards, using the imaging of single line array camera
Feature and conllinear 4 points of Cross ration invariability, calculate single line array camera homography matrix H, solve single line array camera and scaling board
Between make non-uniform movement and cannot calculate the problem of homography matrix H.This method simple system, restrictive condition is few, for single line
Array camera demarcate application is significant and practical value.
Brief description of the drawings
Fig. 1 is the inventive method schematic flow sheet;
Fig. 2 is single line array camera imaging schematic diagram;
In Fig. 2, F is the focus of line-scan digital camera.A, b, c, d are picture point, and A, B, C, D are picture point a, b, c, d are corresponding
Impact point.A', B', C' and D' are the value of A, B, C, D in y-axis.D1, D2, D3, D4 are 4 coplanar calibration lines, dummy line D5
Cross the line of D points and D1, D2, D3 parallel co-planar.
Specific embodiment
Embodiments of the present invention are carried out in detail by technical scheme for a better understanding of the present invention below in conjunction with the accompanying drawings
Explanation.
As shown in figure 1, the present invention carries out the straight line during Hough computings obtain image to gained image first, target is chosen
Point calculates double ratio.According to the characteristics of single line array camera imaging system, the double ratio of impact point is obtained with reference to Cross ration invariability.Using mark
The equation of calibration line in fixed board, tries to achieve the coordinate of D points.
Specific implementation of the invention is as follows:
1. with Hough operation methods extract single line array camera to image in lines, a line in capture plane, this
Row gives the 4 lines scaling boards for photographing(4 line meets following rule:,,,,For that can set certainly according to demand)Image in 4 lines, take intersection point for a, b, c and d;
2. with the double ratio of imaging point a, b, c and d
, ac is a and c distance between two points.Bc, ad and bd are similarly.
3. the double ratio of imaging point a, b, c impact point A, B, C and D corresponding with d is obtained using Cross ration invariability,
And then calculate D points(X, y, z)Coordinate.
Step 1:Obtained using Cross ration invariability
Step 2:As shown in Figure 2, it is considered to a dummy line D5, it and D1, D2, D3 parallel co-planar, D1, D2, D3 and by D
This four parallel lines of point D5 are A', B', C' and D with y-axis intersection point '.By Cross ration invariability, Wo Menyou
Therefore,
Step 3:A, B, C and D can be obtained on four calibration lines of scaling board
Can further obtain:
Step 4:Because 4 calibration lines of scaling board are coplanar, it is in the z coordinate of this target board space coordinate, being can basis
Demand can obtain D points from setting(X, y, z)Coordinate.
4. impact point can calculate corresponding H-matrix to the homography matrix H formula of imaging point
Described step(1)In 4 lines scaling boards, 4 lines meet following rule:,,,,For that can set certainly according to demand.
Step 1:By common line-scan digital camera homography formula
Derive outlet list array camera homography formula
It is scale parameter;
Therefore homography matrix H is
Step 2:By common line-scan digital camera homography formula, according to impact point(X, y, z)With corresponding imaging point coordinates d
(u), zero coordinate points of imager coordinate are the summit in da directions, can calculate homography matrix H.
In order to verify effectiveness of the invention, line-scan digital camera model DALSA Piranha Series Ps 2-2x- is used
04K30, resolution ratio is 1 × 4096, and pixel dimension is 7 μm.The lines parameter of scaling board 4Mm, demarcates board space z-axis coordinate
It is zero.
It should be noted last that, the above embodiments are merely illustrative of the technical solutions of the present invention and it is unrestricted.Although real
Example is applied to be described in detail the present invention, it will be understood by those within the art that, technical scheme is entered
Row modification or equivalent, without departure from the spirit and scope of technical solution of the present invention, it all should cover in power of the invention
In the middle of sharp claimed range.
Claims (4)
1. a kind of computational methods of single line array camera homography matrix H, it is characterised in that:The step of the method, is as follows:
(1) lines in single line array camera image are extracted with Hough operation methods, in a capture plane in lines one
OK, this journey is intersected with 4 lines in the image of the 4 lines scaling boards for photographing, takes intersection point for a, b, c and d;4 lines scaling boards, 4
Bar line meets following rule:D1:Y=0, D2:Y=α, D3:Y=2 α, D4:Y=x+3 α, α are can according to demand from setting;
(2) double ratio CR (a, the b of imaging point a, b, c and d are asked for;c,d);
(3) double ratio CR (A, the B of imaging point a, b, c impact point A, B, C and D corresponding with d are obtained using Cross ration invariability;C, D),
And then calculate D point (x, y, z) coordinate;
Wherein, the calculation procedure of D points (x, y, z) coordinate is as follows:
Step one, a dummy line D5, it and D1, D2, D3 parallel co-planar, D1, D2, D3 and by this four parallel lines of D points D5
It is A', B', C' and D with y-axis intersection point ', there is Cross ration invariability, there are CR (A, B;C, D)=CR (A', B';C',D');
Step 2, A, B, C and D can be obtained on four calibration lines of scaling board
Can further obtain:
It is β in the z coordinate of this target board space coordinate because 4 calibration lines of scaling board are coplanar, is to set certainly according to demand,
D point (x, y, z) coordinate can be obtained;
(4) D points and D points are imaged point coordinates accordingly and substitute into impact point to the homography matrix H formula of imaging point, can calculated
Corresponding H-matrix.
2. computational methods of a kind of single line array camera homography matrix H according to claim 1, it is characterised in that:It is described
The double ratio of four points a, b, c and d is on step (2) cathetus
Ac is a and c distance between two points, and bc is b and c distance between two points, ad is the distance between 2 points of a and d, and bd is b and d
2 points of distances between this.
3. computational methods of a kind of single line array camera homography matrix H according to claim 1, it is characterised in that:It is described
Cross ration invariability is CR (A, B in step (3);C, D)=CR (a, b;c,d).
4. computational methods of a kind of single line array camera homography matrix H according to claim 1, it is characterised in that:It is described
The step of homography matrix H is calculated in step (4) is as follows:
Step one, by common line-scan digital camera homography formula
Derive outlet list array camera homography formula
S is scale parameter;
Therefore homography matrix H is
Step 2, by common line-scan digital camera homography formula, according to impact point D (x, y, z) and corresponding imaging point coordinates d (u),
Zero coordinate points of imager coordinate are the summit in da directions, can calculate homography matrix H.
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CN105653503B (en) * | 2015-12-30 | 2018-04-20 | 东华大学 | A kind of quick plane list being multiplied based on multiple simple matrixes answers method of estimation |
CN106023234B (en) * | 2016-06-08 | 2019-01-08 | 南京航空航天大学 | A kind of linear array CCD camera alignment adjusting method |
CN107462174B (en) * | 2017-06-19 | 2019-06-21 | 北京交通大学 | The method and device of the proportion of utilization factor and frame difference measurements contact net geometric parameter |
CN108428252A (en) * | 2018-03-14 | 2018-08-21 | 河南科技大学 | A kind of single line array camera distortion scaling method |
CN110060305B (en) * | 2019-04-12 | 2022-09-30 | 河南科技大学 | High-precision simplified linear array camera calibration method |
CN112614188B (en) * | 2020-12-07 | 2022-09-16 | 上海交通大学 | Dot-matrix calibration board based on cross ratio invariance and identification method thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101650828A (en) * | 2009-09-07 | 2010-02-17 | 东南大学 | Method for reducing random error of round object location in camera calibration |
US8009930B2 (en) * | 2008-03-26 | 2011-08-30 | City University Of Hong Kong | Auto-calibration method for a projector-camera system |
-
2014
- 2014-07-14 CN CN201410332592.7A patent/CN104123725B/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8009930B2 (en) * | 2008-03-26 | 2011-08-30 | City University Of Hong Kong | Auto-calibration method for a projector-camera system |
CN101650828A (en) * | 2009-09-07 | 2010-02-17 | 东南大学 | Method for reducing random error of round object location in camera calibration |
Non-Patent Citations (2)
Title |
---|
基于单应性约束的重叠视域内多目标定位和匹配技术研究;李方波;《中国优秀硕士学位论文全文数据库 信息科技辑》;20130715(第07期);论文第3.1.1节 * |
多线阵CCD摄像机标定及应用研究;姚庆源;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20140615(第06期);论文第4章第2章第2.1.2、2.1.5-2.1.6节、第4.2-4.3、4.5节 * |
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