CN108537748B - Far field image distortion correction method and system based on angle - Google Patents
Far field image distortion correction method and system based on angle Download PDFInfo
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Abstract
The invention discloses a far-field image distortion correction method and a system based on angles, wherein the method comprises the steps of obtaining measurement parameters including the vertical distance between a measurement track and a camera, the included angle between a target plate and a ground normal and the initial azimuth angle of a rotary table; acquiring a turntable azimuth angle of each far-field image, selecting the far-field image with the same turntable azimuth angle as the initial turntable azimuth angle as a reference image to establish a coordinate system, and determining the initial position coordinates of each cooperative target in the reference image; calculating the relative angle of the rotary table of each far field image, and determining a correction matrix model according to the initial position coordinates and the measurement parameters; and inputting the relative angle of the rotary table corresponding to each far-field image into the correction matrix model to realize the correction of the far-field image. Therefore, the method or the system provided by the invention determines the correction matrix model by taking the relative angle of the turntable as a distortion parameter, realizes the distortion correction of a plurality of far-field images, has short time consumption and simple calculation, and meets the requirements of a laser irradiation performance monitoring system.
Description
Technical Field
The invention relates to the technical field of image distortion correction, in particular to a far-field image distortion correction method and system based on angles.
Background
The laser irradiation performance monitoring system is one of important test systems in a target range identification and shaping test. The system mainly comprises a laser irradiator, a target plate, an imaging device and a turntable. The working principle of the system is as follows: the laser irradiator irradiates a horizontally moving target plate at a certain distance in the air, the rotary table tracks the target plate at a certain distance on the ground in real time, the imaging device is carried on the rotary table, and the imaging device tracks and shoots the target plate. Because the aiming axis of the rotary table and the target plate have a real-time changing included angle, the target plate image acquired by the imaging device has different degrees of distortion, and the accurate identification and subsequent calculation of the target plate in the image are influenced. In order to improve the identification precision of the target plate, the acquired target plate image needs to be corrected. For the far field image, how to correct the far field image is crucial. At present, when distortion correction is carried out on continuously acquired target plate images, characteristic points are required to be manually selected for each target plate image, a correction matrix is obtained for each target plate image, and distortion correction is carried out on each target plate image.
Disclosure of Invention
The invention aims to provide an angle-based far-field image distortion correction method and system, wherein the method takes a relative angle of a rotary table as a distortion parameter to perform distortion correction on a far-field image, is short in time consumption and simple in calculation, and meets the requirements of a laser irradiation performance monitoring device.
In order to achieve the purpose, the invention provides the following scheme:
an angle-based far-field image distortion correction method is applied to a laser irradiation performance monitoring device; the laser irradiation performance monitoring device comprises a laser irradiator, a target plate, a camera, a measuring track, a rotary table and a control terminal; a plurality of cooperative targets are arranged on the target plate, and each cooperative target is marked by a cross line; the measuring track is a track for the target plate to move horizontally; the laser irradiator is arranged in the air and irradiates the horizontally moving target plate; the camera is carried on the rotary table, and the rotary table tracks the target plate in real time, so that the camera tracks and shoots the target plate; the control terminal is connected with the rotary table and the camera; the far-field image distortion correction method includes:
acquiring the vertical distance between the measuring track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal;
acquiring a plurality of continuously acquired far field images;
acquiring the rotating platform azimuth angle of each far-field image, and calculating the rotating platform relative angle of each far-field image; the relative angle of the rotary table is the relative angle between the main optical axis of the camera and the target plate;
selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from the plurality of far-field images as a reference image, and establishing a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is a longitudinal direction which passes through the center of the target plate and is vertical to the Z axis;
calculating the initial position coordinates of each cooperation target in the reference image according to the reference coordinate system;
calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image;
determining the corrected position coordinates of each cooperative target in the reference image by adopting a spatial transformation matrix according to the real distortion coordinates;
obtaining a correction matrix model according to the initial position coordinates and the correction position coordinates of each cooperative target; the correction matrix model is a matrix model containing relative angle parameters of the rotary table;
inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
Optionally, the calculating a relative angle of a rotation table of each far-field image specifically includes:
and determining the difference value between the turntable azimuth angle corresponding to each far-field image and the initial turntable azimuth angle as the turntable relative angle of each far-field image.
Optionally, the calculating a true distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance, and a relative angle of the turntable corresponding to the reference image specifically includes:
determining the center position coordinates of the camera according to the vertical distance; the vertical distance is L, and the center position coordinates are (0,0, L);
calculating a distortion target plate space scaling coefficient of each cooperative target in the reference image according to the initial position coordinate, the relative angle of the rotary table, the included angle and the center position coordinate of the camera; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target board and the ground normal line, β is the relative angle of the rotary table;
according to the initial position coordinates and the phaseCalculating the real distortion coordinate of each cooperative target in the reference image according to the central position coordinate of the machine and the spatial scaling coefficient of the distortion target plate; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the true distortion coordinate of the ith said cooperative target is A'i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)。
Optionally, the corrected position coordinate a ″ of the ith cooperative target in the reference image is calculated according to the following formulai(x″Ai,y″Ai,z″Ai) (ii) a The formula is:
optionally, the obtaining a correction matrix model according to the initial position coordinate of each cooperative target and the correction position coordinate specifically includes:
determining a transformation matrix according to the following formula; the transformation matrix is the correction matrix model; the formula is: [ A "")1A″2...A″n]＝Tn×n[A1A2...An]；Tn×nIs a transformation matrix; [ A "")1A″2...A″n]Corrected position coordinates representing n of the cooperative targets; [ A ]1A2...An]Initial position coordinates of n of the cooperative targets are represented.
Optionally, 4 cooperative targets are arranged on the target plate.
The invention also provides an angle-based far-field image distortion correction system, which is applied to a laser irradiation performance monitoring device; the laser irradiation performance monitoring device comprises a laser irradiator, a target plate, a camera, a measuring track, a rotary table and a control terminal; a plurality of cooperative targets are arranged on the target plate, and each cooperative target is marked by a cross line; the measuring track is a track for the target plate to move horizontally; the laser irradiator is arranged in the air and irradiates the horizontally moving target plate; the camera is carried on the rotary table, and the rotary table tracks the target plate in real time, so that the camera tracks and shoots the target plate; the control terminal is connected with the rotary table and the camera; the far-field image distortion correction system includes:
the first acquisition module is used for acquiring the vertical distance between the measurement track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal;
the second acquisition module is used for acquiring a plurality of continuously acquired far-field images;
the rotating table relative angle calculating module is used for acquiring the rotating table azimuth angle of each far-field image and calculating the rotating table relative angle of each far-field image; the relative angle of the rotary table is the relative angle between the main optical axis of the camera and the target plate;
the reference coordinate system establishing module is used for selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from a plurality of far-field images as a reference image and establishing a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is a longitudinal direction which passes through the center of the target plate and is vertical to the Z axis;
an initial position coordinate calculation module, configured to calculate an initial position coordinate of each of the cooperation targets in the reference image according to the reference coordinate system;
the real distortion coordinate calculation module is used for calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image;
a corrected position coordinate determination module, configured to determine, according to the true distortion coordinate, a corrected position coordinate of each of the cooperative targets in the reference image by using a spatial transformation matrix;
a correction matrix model obtaining module, configured to calculate a correction matrix model according to the initial position coordinates of each of the cooperative targets and the correction position coordinates; the correction matrix model is a matrix model containing relative angle parameters of the rotary table;
the correction module is used for inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
Optionally, the turntable relative angle calculating module specifically includes:
and the turntable relative angle calculation unit is used for determining the difference value between the turntable azimuth angle corresponding to each far-field image and the turntable initial azimuth angle as the turntable relative angle of each far-field image.
Optionally, the real distortion coordinate calculation module specifically includes:
a central position coordinate determination unit for determining a central position coordinate of the camera according to the vertical distance; the vertical distance is L, and the center position coordinates are (0,0, L);
the distorted target plate space scaling coefficient calculation unit is used for calculating the distorted target plate space scaling coefficient of each cooperative target in the reference image according to the initial position coordinate, the relative angle of the rotary table, the included angle and the center position coordinate of the camera; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target board and the ground normal line, β is the relative angle of the rotary table;
a real distortion coordinate calculation unit, configured to calculate a real distortion coordinate of each of the cooperative targets in the reference image according to the initial position coordinate, the center position coordinate of the camera, and the distortion target plate spatial scaling coefficient; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the true distortion coordinate of the ith said cooperative target is A'i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)。
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a far-field image distortion correction method and a far-field image distortion correction system based on angles, wherein the far-field image distortion correction method is applied to a laser irradiation performance monitoring device, and comprises the following steps: acquiring the vertical distance between the measuring track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal; acquiring a plurality of continuously acquired far field images; acquiring the rotating platform azimuth angle of each far-field image, and calculating the rotating platform relative angle of each far-field image; the relative angle of the rotary table is the relative angle between the main optical axis of the camera and the target plate; selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from the plurality of far-field images as a reference image, and establishing a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is a longitudinal direction which passes through the center of the target plate and is vertical to the Z axis; calculating the initial position coordinates of each cooperation target in the reference image according to the reference coordinate system; calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image; determining the corrected position coordinates of each cooperative target in the reference image by adopting a spatial transformation matrix according to the real distortion coordinates; obtaining a correction matrix model according to the initial position coordinates and the correction position coordinates of each cooperative target; the correction matrix model is a matrix model containing relative angle parameters of the rotary table; inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one. Therefore, the method or the system provided by the invention determines the correction matrix by taking the relative angle of the rotary table as a distortion parameter, and further performs distortion correction on all the far-field images according to the correction matrix, does not need to manually select characteristic points for each far-field image, does not need to obtain the correction matrix for each target plate image, has short time consumption and simple calculation, and meets the requirements of a laser irradiation performance monitoring device.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of a laser irradiation performance monitoring apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of a far field image distortion correction method according to an embodiment of the present invention;
FIG. 3 is a reference coordinate system O according to the present invention1-a schematic diagram of XYZ;
fig. 4 is a schematic structural diagram of a far-field image distortion correction system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.
The invention aims to provide an angle-based far-field image distortion correction method and system, wherein the method takes a relative angle of a rotary table as a distortion parameter to perform distortion correction on a far-field image, is short in time consumption and simple in calculation, and meets the requirements of a laser irradiation performance monitoring device.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
The far-field image distortion correction method provided by the invention is applied to a laser irradiation performance monitoring device.
Fig. 1 is a schematic structural diagram of a laser irradiation performance monitoring apparatus according to an embodiment of the present invention; as shown in figure 1 of the drawings, in which,
the laser irradiation performance monitoring device comprises a laser irradiator, a rotary table 1, a control terminal (computer) 2, a camera 3, a measuring track 4 and a target plate 5; the target board is provided with 4 cooperative targets A, B, C and D respectively, each cooperative target is marked by a cross line, and the intersection point of the cross lines needs to be clearly identified in the far field image. The measuring track 4 is a track for the target plate 5 to move horizontally; the laser irradiator is arranged in the air and irradiates the target plate 5 which moves horizontally; the camera 3 is carried on the rotary table 1, the rotary table 1 tracks the target plate 5 at a certain distance from the ground in real time, and the camera 3 tracks and shoots the target plate 5; the control terminal 2 is connected with the rotary table 1 and the camera 3; the far-field image distortion correction method mainly comprises the steps of calibrating parameters, collecting a far-field image, determining a rotating table azimuth angle corresponding to the far-field image, selecting a reference image, establishing a reference coordinate system, calculating an initial position coordinate, a real distortion coordinate and a correction position coordinate of each cooperative target in the reference image, calculating a correction matrix model, and finally carrying out distortion correction on each far-field image according to the correction matrix model and the rotating table azimuth angle corresponding to each far-field image.
Fig. 2 is a schematic flow chart of a far-field image distortion correction method according to an embodiment of the present invention, and as shown in fig. 2, the far-field image distortion correction method provided by the present invention specifically includes the following steps:
step 201: and acquiring the vertical distance between the measuring track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal.
Step 202: and acquiring a plurality of continuously acquired far field images.
Step 203: acquiring the rotating platform azimuth angle of each far-field image, and calculating the rotating platform relative angle of each far-field image; the relative angle of the rotary table is the relative angle between the main optical axis of the camera and the target plate.
Step 204: and selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from the plurality of far-field images as a reference image, and establishing a reference coordinate system according to the reference image.
FIG. 3 is a reference coordinate system O according to the present invention1A schematic diagram of XYZ, as shown in FIG. 3, the origin O of the reference coordinate system1The target plate center of the reference image is taken as the direction of the Z axis of the reference coordinate system, the direction of the target plate center points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the target plate center and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is the longitudinal direction passing through the center of the target plate and perpendicular to the Z axis.
Step 205: and calculating the initial position coordinates of each cooperation target in the reference image according to the reference coordinate system.
Step 206: and calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image.
Step 207: and determining the corrected position coordinates of each cooperative target in the reference image by adopting a spatial transformation matrix according to the real distortion coordinates.
Step 208: obtaining a correction matrix model according to the initial position coordinates and the correction position coordinates of each cooperative target; the correction matrix model is a matrix model containing relative angle parameters of the rotary table.
Step 209: inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
Step 202 specifically includes: the target plate 5 moves along the measuring track 4 at a speed v, the camera 3 tracks the target plate 5, a plurality of continuous far-field images are collected, and the collected continuous far-field images I are1…InStored in the control terminal 2.
Step 203 specifically includes:
the obtained initial azimuth angle of the turntable is the initial azimuth angle theta of the recording turntable through the encoder on the turntable 10。
Acquiring a turntable azimuth angle corresponding to each far field image; for a plurality of collected continuous far-field images I1…InThe bar code in the image acquisition system is identified to obtain the azimuth angle theta of the rotary table of all the far-field images1…θnAnd stored in the control terminal 2.
Determining the difference value between the corresponding turntable azimuth angle of each far-field image and the initial azimuth angle as the turntable relative angle of each far-field image, wherein the turntable relative angle β is thetan-θ0。
Step 206 specifically includes:
the vertical distance between the camera and the track is L; the vertical distance L between the camera 3 and the target plate 5 is measured with a laser rangefinder.
Determining the center position coordinate O of the camera according to the vertical distance L2As shown in fig. 3, the center position coordinates (0,0, L).
Calculating a distortion target plate space scaling coefficient of each cooperative target in the reference image according to the initial position coordinate, the relative angle of the rotary table, the included angle and the center position coordinate of the camera; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target board and the ground normal line, β is the relative angle of the rotary table;
calculating real distortion coordinates of each cooperative target in the reference image according to the initial position coordinates, the central position coordinates of the camera and the distortion target plate space scaling coefficient; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the true distortion coordinate of the ith said cooperative target is A'i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)。
The principle is as follows: as shown in fig. 3, in a reference coordinate system O1At XYZ, the cooperative target A (x)A1,yA10) true distortion coordinate is A '(x'A1,y′A1,z′A1And) the center position of the camera 3 is O2(0,0, L) then there is O2A1＝(xA1,yA1,-L)，O2A′1＝(x′A1,y′A1,z′A1-L) from vectors
And
are collinear with
Point A 'can be calculated'1Coordinate expression of
A′1(x′A1,y′A1,z′A1)＝(kxA1,kyA1,(1-k)L)
A'1Substituting the coordinate expression of (a) into the following plane equation:
xcosαsinβ-ysinα+zcosαcosβ＝0
α, the space scaling coefficient k of the distorted target plate is obtained by taking the included angle between the target plate 5 and the ground normal and β as the relative angle of the turntable:
substituting k into A'1In the point coordinate expression, calculating A'1Point coordinates.
Similarly, B 'shown in FIG. 3 can be calculated'1、C′1、D′1。
Step 207 specifically includes: calculating a corrected position coordinate A' of the ith cooperative target in the reference image according to the following formulai(x″Ai,y″Ai,z″Ai) (ii) a The formula is:
preferably, the coordinate a ″ of the correction position of the cooperative target in the reference image1、B″1、C″1、D″1：
According to
A'1(x′A1,y′A1,z′A1) Rotate to the undistorted target plate corner point A1(x″A1,y″A1,z″A1)。
Can be found out of'1、C′1、D′1B ″)1、C″1、D″1
Step 208 specifically includes:
determining a transformation matrix according to the following formula; the transformation matrix is the correction matrix model; the formula is: [ A "")1A″2...A″n]＝Tn×n[A1A2...An]；Tn×nIs a transformation matrix; [ A "")1A″2...A″n]Representing n undistorted target plate angular point coordinates; [ A ]1A2...An]Representing the coordinates of a plurality n of said corner points.
Since the number of cooperation targets is 4, the transformation matrix of the reference image is T4×4: using the relation of four pairs of corresponding points to find the transformation matrix T4×4。
[A″ B″ C″ D″]＝T4×4[A B C D]。
The method provided by the embodiment of the invention uses the relative angle β of the rotating table of the main optical axis of the camera 3 relative to the target plate 5 as a reference variable, calculates the coordinate projection of a distorted image control point according to a camera imaging model, a perspective transformation principle and geometric transformation, obtains a distortion-free control point by using a spatial transformation matrix, solves a transformation matrix (a correction matrix) according to the corresponding relation between the distorted image coordinate and an ideal image coordinate, and performs distortion correction on the whole image
In order to achieve the above object, the present invention further provides an angle-based far field image distortion correction system. The far-field image distortion correction system is applied to the laser irradiation performance monitoring device shown in fig. 1.
Fig. 4 is a schematic structural diagram of a far-field image distortion correction system according to an embodiment of the present invention, and as shown in fig. 4, the far-field image distortion correction system according to the embodiment of the present invention includes:
the first obtaining module 401 is configured to obtain a vertical distance between the measurement track and the camera, an initial azimuth angle of the turntable at the same time, and an included angle between the target plate and a ground normal.
A second acquiring module 402, configured to acquire a plurality of continuously acquired far-field images.
A turntable relative angle calculation module 403, configured to obtain a turntable azimuth angle of each far-field image, and calculate a turntable relative angle of each far-field image; the relative angle of the rotary table is the relative angle between the main optical axis of the camera and the target plate.
A reference coordinate system establishing module 404, configured to select an image with the same turntable azimuth as the turntable initial azimuth from multiple far-field images as a reference image, and establish a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is the longitudinal direction passing through the center of the target plate and perpendicular to the Z axis.
An initial position coordinate calculation module 405, configured to calculate an initial position coordinate of each of the cooperation targets in the reference image according to the reference coordinate system.
A true distortion coordinate calculation module 406, configured to calculate a true distortion coordinate of each of the cooperative targets in the reference image according to the initial position coordinate, the included angle, the vertical distance, and a relative angle of the turntable corresponding to the reference image.
A corrected position coordinate determining module 407, configured to determine, according to the true distortion coordinate, a corrected position coordinate of each of the cooperation targets in the reference image by using a spatial transformation matrix.
A correction matrix model obtaining module 408, configured to calculate a correction matrix model according to the initial position coordinates of each of the cooperative targets and the correction position coordinates; the correction matrix model is a matrix model containing relative angle parameters of the rotary table.
A correcting module 409, configured to input the relative angle of the turntable corresponding to the uncorrected far-field image into the correction matrix model, obtain a correction matrix of the uncorrected far-field image, and correct the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
The turntable relative angle calculating module 403 specifically includes:
and the turntable relative angle calculation unit is used for determining the difference value between the turntable azimuth angle corresponding to each far-field image and the turntable initial azimuth angle as the turntable relative angle of each far-field image.
The real distortion coordinate calculation module 406 specifically includes:
a central position coordinate determination unit for determining a central position coordinate of the camera according to the vertical distance; the vertical distance is L, and the center position coordinates are (0,0, L);
a distortion target plate space scaling factor calculation unit for calculating each cooperation target in the reference image according to the initial position coordinate, the relative angle of the turntable, the included angle and the center position coordinate of the cameraTarget distortion target plate spatial scaling factor; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target board and the ground normal line, β is the relative angle of the rotary table;
a real distortion coordinate calculation unit, configured to calculate a real distortion coordinate of each of the cooperative targets in the reference image according to the initial position coordinate, the center position coordinate of the camera, and the distortion target plate spatial scaling coefficient; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the true distortion coordinate of the ith said cooperative target is A'i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)。
The far-field image distortion correction system provided by the embodiment of the invention can be used for correcting a far-field image by simply taking an angle as a distortion parameter, eliminating the influence of the included angle α between the target plate 5 and the ground normal and the actual rotating relative angle β of the camera 3 in a laser irradiator performance monitoring device on the distortion of the far-field image, eliminating the need of manually selecting characteristic points for each far-field image and solving a correction matrix for each target plate image, and being short in time consumption and simple in calculation, overcoming the defects of incomplete target identification, low hit rate precision, inaccurate positioning and the like, and meeting the requirements of the laser irradiation performance monitoring device.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (5)
1. An angle-based far field image distortion correction method is characterized in that the far field image distortion correction method is applied to a laser irradiation performance monitoring device; the laser irradiation performance monitoring device comprises a laser irradiator, a target plate, a camera, a measuring track, a rotary table and a control terminal; a plurality of cooperative targets are arranged on the target plate, and each cooperative target is marked by a cross line; the measuring track is a track for the target plate to move horizontally; the laser irradiator is arranged in the air and irradiates the horizontally moving target plate; the camera is carried on the rotary table, and the rotary table tracks the target plate in real time, so that the camera tracks and shoots the target plate; the control terminal is connected with the rotary table and the camera; the far-field image distortion correction method includes:
acquiring the vertical distance between the measuring track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal;
acquiring a plurality of continuously acquired far field images;
acquiring the rotating platform azimuth angle of each far-field image, and calculating the rotating platform relative angle of each far-field image; the relative angle of the rotary table is the difference value between the rotary table azimuth angle corresponding to each far field image and the rotary table initial azimuth angle;
selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from the plurality of far-field images as a reference image, and establishing a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is a longitudinal direction which passes through the center of the target plate and is vertical to the Z axis;
calculating the initial position coordinates of each cooperation target in the reference image according to the reference coordinate system;
calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image; the method specifically comprises the following steps: determining the center position coordinates of the camera according to the vertical distance; the vertical distance is L, and the center position coordinates are (0,0, L);
calculating a distortion target plate space scaling coefficient of each cooperative target in the reference image according to the initial position coordinate, the relative angle of the rotary table, the included angle and the center position coordinate of the camera; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target plate and the ground normal line, β is the relative angle of the turntable corresponding to the reference image;
calculating real distortion coordinates of each cooperative target in the reference image according to the initial position coordinates, the central position coordinates of the camera and the distortion target plate space scaling coefficient; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the real distortion coordinate of the ith said cooperative target is
A′i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)；
Determining the corrected position coordinates of each cooperative target in the reference image by adopting a spatial transformation matrix according to the real distortion coordinates;
obtaining a correction matrix model according to the initial position coordinates and the correction position coordinates of each cooperative target; the correction matrix model is a matrix model containing relative angle parameters of the rotary table;
inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
2. The far field image distortion correction method according to claim 1, wherein the correction position coordinate a "of the i-th cooperative target in the reference image is calculated according to the following formulai(x″Ai,y″Ai,z″Ai) (ii) a The formula is:
3. the far-field image distortion correction method according to claim 2, wherein the obtaining a correction matrix model according to the initial position coordinates and the correction position coordinates of each of the cooperative targets specifically includes:
determining a transformation matrix according to the following formula; the transformation matrix is the correction matrix model; the formula is: [ A "")1A″2... A″n]＝Tn×n[A1A2... An]；Tn×nIs a transformation matrix; [ A "")1A″2... A″n]Corrected position coordinates representing n of the cooperative targets; [ A ]1A2... An]Initial position coordinates of n of the cooperative targets are represented.
4. The far-field image distortion correction method according to claim 1, wherein 4 cooperative targets are provided on the target board.
5. An angle-based far-field image distortion correction system is characterized in that the far-field image distortion correction system is applied to a laser irradiation performance monitoring device; the laser irradiation performance monitoring device comprises a laser irradiator, a target plate, a camera, a measuring track, a rotary table and a control terminal; a plurality of cooperative targets are arranged on the target plate, and each cooperative target is marked by a cross line; the measuring track is a track for the target plate to move horizontally; the laser irradiator is arranged in the air and irradiates the horizontally moving target plate; the camera is carried on the rotary table, and the rotary table tracks the target plate in real time, so that the camera tracks and shoots the target plate; the control terminal is connected with the rotary table and the camera; the far-field image distortion correction system includes:
the first acquisition module is used for acquiring the vertical distance between the measurement track and the camera, the initial azimuth angle of the rotary table at the same moment and the included angle between the target plate and the ground normal;
the second acquisition module is used for acquiring a plurality of continuously acquired far-field images;
the rotating table relative angle calculating module is used for acquiring the rotating table azimuth angle of each far-field image and calculating the rotating table relative angle of each far-field image; the relative angle of the rotary table is the difference value between the rotary table azimuth angle corresponding to each far field image and the rotary table initial azimuth angle;
the reference coordinate system establishing module is used for selecting an image with the same rotating table azimuth angle as the initial rotating table azimuth angle from a plurality of far-field images as a reference image and establishing a reference coordinate system according to the reference image; the origin of the reference coordinate system is the center of the target plate of the reference image, the direction of the Z axis of the reference coordinate system is the direction in which the center of the target plate points to the optical center of the camera, and the direction of the X axis of the reference coordinate system is the transverse direction which passes through the center of the target plate and is perpendicular to the Z axis; the direction of the Y axis of the reference coordinate system is a longitudinal direction which passes through the center of the target plate and is vertical to the Z axis;
an initial position coordinate calculation module, configured to calculate an initial position coordinate of each of the cooperation targets in the reference image according to the reference coordinate system;
the real distortion coordinate calculation module is used for calculating the real distortion coordinate of each cooperative target in the reference image according to the initial position coordinate, the included angle, the vertical distance and the relative angle of the rotary table corresponding to the reference image; the real distortion coordinate calculation module specifically includes:
a central position coordinate determination unit for determining a central position coordinate of the camera according to the vertical distance; the vertical distance is L, and the center position coordinates are (0,0, L);
the distorted target plate space scaling coefficient calculation unit is used for calculating the distorted target plate space scaling coefficient of each cooperative target in the reference image according to the initial position coordinate, the relative angle of the rotary table, the included angle and the center position coordinate of the camera; if the coordinate of the ith cooperation target is Ai(xAi,yAi0), then the distortion target plate space scaling factor in the ith cooperative target is:
α is the included angle between the target plate and the ground normal line, β is the relative angle of the turntable corresponding to the reference image;
a real distortion coordinate calculation unit, configured to calculate a real distortion coordinate of each of the cooperative targets in the reference image according to the initial position coordinate, the center position coordinate of the camera, and the distortion target plate spatial scaling coefficient; if the ith one isThe coordinate of the cooperation target is Ai(xAi,yAi0), then the true distortion coordinate of the ith said cooperative target is A'i(x′Ai,y′Ai,z′Ai)＝(kixAi,kiyAi,(1-ki)L)；
A corrected position coordinate determination module, configured to determine, according to the true distortion coordinate, a corrected position coordinate of each of the cooperative targets in the reference image by using a spatial transformation matrix;
a correction matrix model obtaining module, configured to calculate a correction matrix model according to the initial position coordinates of each of the cooperative targets and the correction position coordinates; the correction matrix model is a matrix model containing relative angle parameters of the rotary table;
the correction module is used for inputting the relative angle of the rotary table corresponding to the uncorrected far-field image into the correction matrix model to obtain a correction matrix of the uncorrected far-field image, and correcting the uncorrected far-field image according to the correction matrix; wherein the uncorrected far field images correspond to the correction matrix one to one.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6416186B1 (en) * | 1999-08-23 | 2002-07-09 | Nec Corporation | Projection display unit |
| CN102915171A (en) * | 2011-08-04 | 2013-02-06 | 王振兴 | Moving trajectory generation method |
Family Cites Families (1)
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-
2018
- 2018-03-27 CN CN201810257901.7A patent/CN108537748B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6416186B1 (en) * | 1999-08-23 | 2002-07-09 | Nec Corporation | Projection display unit |
| CN102915171A (en) * | 2011-08-04 | 2013-02-06 | 王振兴 | Moving trajectory generation method |
Non-Patent Citations (2)
| Title |
|---|
| 《一种基于模板匹配的远场畸变校正方法》;黄殿君等;《长春理工大学学报（自然科学版）》;20141231;第37卷(第6期);第127-133页 * |
| Sturm等.《Camera Models and Fundamental Concepts Used in Geometric Computer Vision》.《Foundations and Trends® in Computer Graphics and Vision》.2010, * |
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