Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a zero calibration method and a zero calibration system for screen observation equipment, which can solve the problems of very complicated operation process and low precision in the prior art by manually adjusting the mode that the central point of the screen observation equipment is overlapped with the central point of a screen.
In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:
on one hand, the invention provides a method for calibrating the machine position of screen observation equipment, which is characterized by comprising the following steps:
generating a plurality of observation points on a screen, establishing a screen coordinate system by taking a selected point on the screen as an origin, and determining the pixel position of each observation point in the screen coordinate system and the observation angle parameter of each observation point observed by observation equipment;
establishing an observation matrix equation of the observation point pixel position and the observation angle parameter of each observation point relative to the position parameter to be calibrated of the observation equipment;
and determining the position parameter to be calibrated of the observation equipment according to the observation matrix equation of the observation point.
In some optional embodiments, the establishing an observation matrix equation of the observation point pixel position and the observation angle parameter of each observation point with respect to the to-be-calibrated position parameter of the observation device includes the following steps:
determining the distance x from the observation point P to the central point of the observation equipment in the horizontal direction relative to the observation angle parameter according to the observation angle parameterpAnd a distance y to the center point of the observation device in the vertical directionpThe relational expression of (1);
determining a pixel factor k in a horizontal direction of a screenxiAnd a pixel factor k in the vertical directionyiAnd according to kxi、kyiAnd observation point pixel location determination xpAnd ypThe expression of (1);
according to xpAnd ypAnd xpAnd ypAnd establishing an observation matrix equation of the pixel position and the observation parameter relative to the position parameter to be calibrated.
In some alternative embodiments, x is
pAnd y
pThe relation formula of the observation angle parameter is
And
wherein alpha is the elevation angle of the observation point observed by the observation equipment, beta is the azimuth angle of the observation point observed by the observation equipment, and l is the distance from the observation equipment to the screen.
In some optional embodiments, the pixel factor k for determining the horizontal direction of the screen is describedxiAnd a pixel factor k in the vertical directionyiAnd according to kxi、kyiAnd observation point pixel location determination xpAnd ypThe expression (2) specifically includes:
according to the formula
Determining a pixel factor k in a horizontal direction of a screen
xiAnd a pixel factor k in the vertical direction
yiWherein x is
imaxResolution in the horizontal direction, y
imaxThe resolution in the vertical direction is L, the length of the screen and W, the width of the screen;
according to k
xi、k
yiAnd the observation point pixel position, determining x
pAnd y
pWith respect to k
xi、k
yiAnd expression of observation point pixel position
Wherein x is
ioThe position of the observation center pixel of the center point of the observation device in the horizontal direction of the screen, y
ioThe pixel position of the observation central point of the observation equipment central point in the vertical direction of the screen, x
ipThe observation point pixel position, y, of the observation point P in the horizontal direction of the screen
ipThe pixel position of the observation point P in the vertical direction of the screen is taken as the observation point.
In some alternative embodiments, said is according to xpAnd ypAnd xpAnd ypThe expression of (2) establishing an observation matrix equation of the pixel position and the observation parameter with respect to the position parameter to be calibrated, comprising:
simultaneous formula relation
And expression
Observation equation set for obtaining observation point pixel position and observation angle parameter relative to-be-calibrated position parameter of observation equipment
Observing the system of equations
The obtained observation matrix equation y is Cx, wherein the position parameter matrix to be calibrated
Matrix of observation point pixel locations
Observation angle parameter matrix
In some optional embodiments, the position parameter to be calibrated of the observation device is determined based on a recursive least square method or a general least square method.
In some optional embodiments, the determining the to-be-calibrated position parameter of the observation device by using a recursive least square method includes the following steps:
an observation value matrix z of a k-th group observation point pixel position matrix y in consideration of an observation error of an observation point pixel positionkIs zk=Ckxk+νk(k=1,2,...,n),νkObservation error of k and observation point;
based on the least square method, according to zk=Ckxk+νk(k ═ 1, 2.., n), estimate calibration parameter matrix xnRecursion formula of
Wherein x is
kVariance P of
k=Var(x
k),ν
kVariance R of
k=Var(ν
k),
l
0Is a set initial value of l;
the observation point pixel positions (x) of the k observation point are sequentially substitutedipk,yipk) And observation angle parameter (alpha)k,βk) Obtaining an estimated value calibration parameter matrix x related to the pixel position of the observation central point and the distance l between the observation equipment and the screen through iteration for setting the iteration times n times to a recurrence formulan。
In some optional embodiments, the determining the position parameter to be calibrated of the observation device by using a general least square method includes the following steps:
with the center of the screen as the origin and the inner diameter r1Outer diameter of r2Randomly generating n observation points in the circular ring;
obtaining a correction equation according to an observation matrix equation y of n observation points
Wherein the observation point corrects the position matrix
Observation angle correction matrix
Solving for
Obtaining a corrected calibration parameter matrix related to the pixel position of the observation central point and the distance l from the observation equipment to the screen
On the other hand, the invention provides a system for calibrating the position of a screen observation device, which comprises:
the input module is used for randomly generating a plurality of observation points on the screen, establishing a screen coordinate system by taking a selected point on the screen as an original point, and determining the pixel position of each observation point in the screen coordinate system and the observation angle parameter of each observation point observed by the observation equipment;
the analysis module is used for establishing an observation matrix equation of the observation point pixel position and the observation angle parameter of each observation point relative to the position parameter to be calibrated of the observation equipment; and determining the position parameters to be calibrated of the observation equipment according to the observation matrix equation of the plurality of observation points.
In some optional embodiments, the analysis module comprises:
a first positioning unit for determining the distance x from the observation point P to the center point of the observation device in the horizontal direction according to the observation angle parameterpAnd a distance y to the center point of the observation device in the vertical directionpThe relational expression of (1);
a second positioning unit for determining a pixel factor k in a horizontal direction of the screenxiAnd a pixel factor k in the vertical directionyiAnd according to kxi、kyiAnd observation point pixel location determination xpAnd ypThe expression of (1);
an analysis unit for analyzing according to xpAnd ypAnd xpAnd ypAnd establishing an observation matrix equation of the pixel position and the observation parameter relative to the position parameter to be calibrated.
Compared with the prior art, the invention has the advantages that: firstly, establishing an observation matrix equation of a position parameter to be calibrated of observation equipment according to an observation point pixel position and an observation angle parameter of each observation point; the observation matrix equation passing through a plurality of observation points can be solved in a mathematical mode, so that the position parameter to be calibrated of the observation equipment can be determined. The distance between the focal point of the television equipment and the projection screen does not need to be obtained through measurement, the central point of the observation equipment, namely the position of the focal point projected in the screen, can be quickly and accurately positioned, and the calibration work of the observation equipment is greatly simplified.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. As shown in fig. 1-2:
the invention provides a method for calibrating a machine position of screen observation equipment, which comprises the following steps:
s1: generating a plurality of observation points on a screen, establishing a screen coordinate system by taking a selected point on the screen as an origin, and determining the pixel position of each observation point in the screen coordinate system and the observation angle parameter of each observation point observed by an observation device.
As shown in FIG. 2, an observation apparatus is providedThe central point, i.e. the focal point projected on the screen, is OcThe intersection point of the axis of the observation device and the screen is O, and the distance from the observation device to the screen is l. And establishing a plane coordinate system Oxy on the screen by taking the point O as a coordinate origin, and setting P as an observation point, wherein projection sub-tables of the observation point on Ox and Oy are N and M. The television viewing device outputs a high and low angle alpha and an azimuth angle beta. Defining low angle alpha ═ MOcO, azimuth angle beta ═ NOcAnd O, dividing the projection screen into four quadrants by a coordinate system Oxy, wherein the elevation angle in the quadrant I, II is positive, and the azimuth angles in the quadrants II and III are positive.
S2: and establishing an observation matrix equation of the observation point pixel position and the observation angle parameter of each observation point relative to the position parameter to be calibrated of the observation equipment.
Step S2 specifically includes:
s21: determining the distance x from the observation point P to the central point of the observation equipment in the horizontal direction relative to the observation angle parameter according to the observation angle parameterpAnd a distance y to the center point of the observation device in the vertical directionpThe relational expression (c) of (c).
Preferably, x
pAnd y
pThe relation formula of the observation angle parameter is
And
wherein alpha is the elevation angle of the observation point observed by the observation equipment, beta is the azimuth angle of the observation point observed by the observation equipment, and l is the distance from the observation equipment to the screen.
S22: determining a pixel factor k in a horizontal direction of a screenxiAnd a pixel factor k in the vertical directionyiAnd according to kxi、kyiAnd observation point pixel location determination xpAnd ypIs described in (1).
Preferably according to a formula
Determining a pixel factor k in a horizontal direction of a screen
xiI.e. the length of a single pixel, anPixel factor k in vertical direction
yiI.e. the width of a pixel, where x
imaxResolution in the horizontal direction, y
imaxIn the vertical direction, L is the length of the screen and W is the width of the screen.
According to k
xi、k
yiAnd observing point pixel position, determining x
pAnd y
pWith respect to k
xi、k
yiAnd expression of observation point pixel position
Wherein x is
ioThe position of the observation center pixel of the center point of the observation device in the horizontal direction of the screen, y
ioThe pixel position of the observation central point of the observation equipment central point in the vertical direction of the screen, x
ipThe observation point pixel position, y, of the observation point P in the horizontal direction of the screen
ipThe pixel position of the observation point P in the vertical direction of the screen is taken as the observation point.
S23: according to xpAnd ypAnd xpAnd ypAnd establishing an observation matrix equation of the pixel position and the observation parameter relative to the position parameter to be calibrated.
Preferably, the simultaneous formula relation
And expression
Observation equation set for obtaining observation point pixel position and observation angle parameter relative to-be-calibrated position parameter of observation equipment
Observing the system of equations
The obtained observation matrix equation y is Cx, wherein the position parameter matrix to be calibrated
Matrix of observation point pixel locations
Observation angle parameter matrix
In this embodiment, there is no precedence order between steps S21 and S22.
S3: and determining the position parameter to be calibrated of the observation equipment according to the observation matrix equation of the observation point.
Preferably, the position parameter to be calibrated of the observation device is determined based on a recursive least square method or a general least square method.
As shown in fig. 3, when the recursive least square method is adopted to determine the position parameter to be calibrated of the observation device, the method preferably includes the following steps:
an observation value matrix z of a k-th group observation point pixel position matrix y in consideration of an observation error of an observation point pixel positionkIs zk=Ckxk+νk(k=1,2,...,n),νkObservation error of k and observation point;
based on the least square method, according to zk=Ckxk+νk(k ═ 1, 2.., n), estimate calibration parameter matrix xnRecursion formula of
Wherein x is
kVariance P of
k=Var(x
k),ν
kVariance R of
k=Var(ν
k),
l
0Is a set initial value of l;
the observation point pixel positions (x) of the k observation point are sequentially substitutedipk,yipk) And observation angle parameter (alpha)k,βk) To a recurrence formula, passingSetting iteration times n times to obtain an estimated value calibration parameter matrix x related to the pixel position of the observation central point and the distance l between the observation equipment and the screenn。
In solving for
When the initial value is brought into the above formula, the initial value can be arranged into
Observation point pixel position (x) with k-th observation point
ipk,y
ipk) And observation angle parameter (alpha)
k,β
k) Then, then
xk+1=xk+Kk+1(zk+1-Ck+1xk)
Pk=(I3×3-KkCk)Pk-1
Wherein I is an identity matrix, Kk+1An intermediate quantity in the middle abbreviation.
Obtaining an estimated value calibration parameter matrix x related to the pixel position of the observation central point and the distance l between the observation equipment and the screen through iteration of the set iteration times n timesn。
As shown in fig. 4, preferably, when a general least square method is used to determine the position parameter of the observation device to be calibrated, the method includes the following steps:
with the center of the screen as the origin and the inner diameter r1Outer diameter of r2Randomly generating n observation points in the circular ring.
Obtaining a correction equation according to an observation matrix equation y of n observation points
Wherein the observation point corrects the position matrix
Observation angle correction matrix
Solving for
Obtaining a corrected calibration parameter matrix related to the pixel position of the observation central point and the distance l from the observation equipment to the screen
In the present embodiment, the observation point position is generated as follows:
{(xipk,yipk)|xipk=[r1+rand(n)·(r2-r1)]cos(rand(n)·2π),yipk=[r1+rand(n)·(r2-r1)]sin(rand(n)·2π)},
i.e. with the center of the screen as the origin and the inner diameter r1Outer diameter of r2Randomly generating n observation points in the circular ring. Wherein rand (n) represents random n times.
on the other hand, the invention also provides a system for calibrating the machine position of the screen observation equipment, which comprises the following components:
the input module is used for randomly generating a plurality of observation points on the screen, establishing a screen coordinate system by taking a selected point on the screen as an original point, and determining the pixel position of each observation point in the screen coordinate system and the observation angle parameter of each observation point observed by the observation equipment; the system comprises an observation device, an analysis module and a calibration module, wherein the observation device comprises an observation device, a calibration module and a calibration module, wherein the observation device comprises an observation device, the calibration module is used for calibrating the observation device, and the calibration module is used for establishing an observation matrix equation of an observation point pixel position and an observation angle parameter of each observation point relative to a to-be-calibrated position parameter of the observation device; and determining the position parameters to be calibrated of the observation equipment according to the observation matrix equation of the plurality of observation points.
In some optional embodiments, the analysis module comprises: a first positioning unit for determining the distance x from the observation point P to the center point of the observation device in the horizontal direction according to the observation angle parameterpAnd a distance y to the center point of the observation device in the vertical directionpThe relational expression of (1); also included is a second positioning unit for determining a pixel factor k in the horizontal direction of the screenxiAnd a pixel factor k in the vertical directionyiAnd according to kxi、kyiAnd observation point pixel location determination xpAnd ypThe expression of (1); further comprising an analysis unit for analyzing according to xpAnd ypAnd xpAnd ypAnd establishing an observation matrix equation of the pixel position and the observation parameter relative to the position parameter to be calibrated.
In the above embodiment, the observation points are generated pseudo-randomly. The observation points which are distributed randomly accord with the requirement of the least square method for the distribution of the observation errors, the randomness of the distribution of the observation points can be ensured, the situation that the relative error of small-angle measurement close to the circle center is large is avoided, and the estimation precision is ensured.
In summary, the method and the system firstly establish an observation matrix equation of the position parameter to be calibrated of the observation equipment according to the observation point pixel position and the observation angle parameter of each observation point; the observation matrix equation passing through a plurality of observation points can be solved in a mathematical mode, so that the position parameter to be calibrated of the observation equipment can be determined. The distance between the focal point of the television equipment and the projection screen does not need to be obtained through measurement, the central point of the observation equipment, namely the position of the focal point projected in the screen, can be quickly and accurately positioned, and the calibration work of the observation equipment is greatly simplified.
In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.