CN115294028A - Registration plate calibration method and device - Google Patents

Registration plate calibration method and device Download PDF

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Publication number
CN115294028A
CN115294028A CN202210806537.1A CN202210806537A CN115294028A CN 115294028 A CN115294028 A CN 115294028A CN 202210806537 A CN202210806537 A CN 202210806537A CN 115294028 A CN115294028 A CN 115294028A
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coordinates
marker
calibration
image
coordinate system
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李明
沈丽萍
牛乾
王金海
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Hangzhou Santan Medical Technology Co Ltd
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Hangzhou Santan Medical Technology Co Ltd
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/0002—Inspection of images, e.g. flaw detection
    • G06T7/0004—Industrial image inspection
    • G06T7/001—Industrial image inspection using an image reference approach
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/30—Determination of transform parameters for the alignment of images, i.e. image registration
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/10—Image acquisition modality
    • G06T2207/10004—Still image; Photographic image

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  • Computer Vision & Pattern Recognition (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

The embodiment of the invention provides a registration plate calibration method and a registration plate calibration device, which relate to the technical field of data processing, and the method comprises the following steps: obtaining a fluoroscopic image containing a plurality of fiducial markers and a registration plate; detecting image coordinates of each reference mark object and each target mark object in the perspective image; obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system; and determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker. By applying the registration plate calibration scheme provided by the embodiment of the invention, the calibration accuracy of the registration plate can be improved.

Description

Registration plate calibration method and device
Technical Field
The invention relates to the technical field of data processing, in particular to a registration plate calibration method and a registration plate calibration device.
Background
Nowadays, registration plates have been widely used in various registration scenarios such as image registration and point cloud registration. The registration plate includes a marker, and before registration is performed by using the registration plate, coordinates of the marker in a calibration coordinate system where the registration plate is located need to be determined, which is called a registration plate calibration process.
In the prior art, before a registration plate is manufactured, coordinates of a marker in a calibration coordinate system are preset, and then the registration plate is manufactured based on the set coordinates of the marker, so that the registration plate calibration is realized. However, the method has high requirements on the manufacturing process of the registration plate, and errors are easy to occur in the manufacturing process, so that the calibration accuracy of the registration plate is low.
Disclosure of Invention
The embodiment of the invention aims to provide a registration plate calibration method and a registration plate calibration device so as to improve the accuracy of registration plate calibration. The specific technical scheme is as follows:
in a first aspect, an embodiment of the present invention provides a registration plate calibration method, where the method includes:
obtaining a fluoroscopic image comprising a plurality of fiducial markers and a registration plate, wherein a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on the surface of the registration plate;
detecting image coordinates of each reference mark object and each target mark object in the perspective image;
obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system;
and determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
In an embodiment of the present invention, the determining coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each fiducial marker, and the calibration coordinates of each fiducial marker includes:
determining a conversion relation between an image coordinate system where the perspective image is located and the calibration coordinate system according to the image coordinate of each reference mark and the calibration coordinate of each reference mark;
and converting the image coordinates of each target marker into coordinates in the calibration coordinate system based on the determined conversion relation.
In an embodiment of the present invention, the determining coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each fiducial marker, and the calibration coordinates of each fiducial marker includes:
determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object;
and determining coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
In an embodiment of the present invention, the detecting image coordinates of each fiducial marker and each target marker in the fluoroscopic image includes:
for each of the respective fiducial markers and the respective target markers, coordinates of a centroid of the marker in the fluoroscopic image are detected as image coordinates of the marker.
In one embodiment of the present invention, the detecting coordinates of the centroid of the marker in the fluoroscopic image includes:
detecting the region of the marker in the perspective image;
and performing weighted average calculation on the coordinates of the pixel points in the detected area according to the weight coefficients of the pixel points in the detected area to obtain the calculated coordinates of the centroid of the marker, wherein the weight coefficients of the pixel points are determined according to the pixel values of the pixel points.
In an embodiment of the present invention, the preset calibration coordinate system is: a coordinate system corresponding to the coordinate measuring instrument;
the obtaining of the calibration coordinates of each reference mark under the preset calibration coordinate system includes:
and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
In an embodiment of the invention, in the case that the calibration coordinate system is a two-dimensional coordinate system, the perspective image is a two-dimensional image, and the number of the fiducial markers is at least two;
and under the condition that the calibration coordinate system is a three-dimensional coordinate system, the perspective image is a three-dimensional image, and the number of the fiducial markers is at least three.
In one embodiment of the present invention, the size difference between the fiducial marker and the target marker is less than or equal to a predetermined difference.
In a second aspect, an embodiment of the present invention further provides a registration plate calibration apparatus, where the apparatus includes:
the image acquisition module is used for acquiring a perspective image containing a plurality of fiducial markers and a registration plate, wherein a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on the surface of the registration plate;
a coordinate detection module for detecting image coordinates of each reference mark object and each target mark object in the perspective image;
the coordinate obtaining module is used for obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system;
and the coordinate determination module is used for determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
In an embodiment of the present invention, the coordinate determination module is specifically configured to:
determining a conversion relation between an image coordinate system where the perspective image is located and the calibration coordinate system according to the image coordinate of each reference mark and the calibration coordinate of each reference mark;
and converting the image coordinates of each target marker into coordinates in the calibration coordinate system based on the determined conversion relation.
In an embodiment of the present invention, the coordinate determination module is specifically configured to:
determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object;
and determining coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
In an embodiment of the present invention, the coordinate detecting module includes:
and the mass center detection sub-module is used for detecting the coordinates of the mass center of each marker in the perspective image as the image coordinates of each marker aiming at each reference marker and each marker in each target marker.
In an embodiment of the present invention, the centroid detecting sub-module is specifically configured to:
detecting the area of the marker in the perspective image;
and performing weighted average calculation on the coordinates of the pixel points in the detected area according to the weight coefficient of the pixel points in the detected area to obtain the calculated coordinates of the centroid of the marker, wherein the weight coefficient of the pixel point is determined according to the pixel value of the pixel point.
In an embodiment of the present invention, the preset calibration coordinate system is: a coordinate system corresponding to the coordinate measuring instrument;
the coordinate obtaining module is specifically configured to:
and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
In an embodiment of the invention, in the case that the calibration coordinate system is a two-dimensional coordinate system, the perspective image is a two-dimensional image, and the number of the fiducial markers is at least two;
and under the condition that the calibration coordinate system is a three-dimensional coordinate system, the perspective image is a three-dimensional image, and the number of the fiducial markers is at least three.
In one embodiment of the present invention, the size difference between the fiducial marker and the target marker is less than or equal to a predetermined difference.
In a third aspect, an embodiment of the present invention further provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, where the processor, the communication interface, and the memory complete mutual communication through the communication bus;
a memory for storing a computer program;
a processor adapted to perform the method steps of any of the above first aspects when executing a program stored in the memory.
In a fourth aspect, the present invention further provides a computer-readable storage medium, in which a computer program is stored, and the computer program, when executed by a processor, implements the method steps in any one of the above first aspects.
The embodiment of the invention has the following beneficial effects:
as can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the plurality of target markers are embedded in the calibrated registration plate, and in order to calibrate the registration plate, the reference markers are placed on the surface of the registration plate, so that when the registration plate is calibrated, not only the image coordinates of each target marker can be detected, but also the image coordinates of each reference marker can be detected, and the calibration coordinates of each reference marker can be obtained, so that the image coordinates of the target markers in the image coordinate system, the image coordinates of the reference markers and the calibration coordinates of the reference markers can be accurately converted to the coordinates in the calibration coordinate system. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, 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 that other embodiments can be obtained by referring to these drawings.
Fig. 1 is a schematic flow chart of a first registration plate calibration method according to an embodiment of the present invention;
fig. 2 is a schematic flowchart of a second registration plate calibration method according to an embodiment of the present invention;
fig. 3 is a schematic flowchart of a third registration plate calibration method according to an embodiment of the present invention;
fig. 4 is a schematic flowchart of a fourth registration plate calibration method according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of a fifth registration plate calibration method according to an embodiment of the present invention;
fig. 6 is a schematic flowchart of a sixth registration plate calibration method according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of a first registration plate calibration apparatus according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a second registration plate calibration apparatus provided in an embodiment of the present invention;
fig. 9 is a schematic structural diagram of an electronic device according to an embodiment of the 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 obtained by those of ordinary skill in the art based on the embodiments of the present invention are within the scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic flowchart of a first registration plate calibration method according to an embodiment of the present invention, where the method includes the following steps S101 to S104.
Step S101: a fluoroscopic image is obtained that includes a plurality of fiducial markers and a registration plate.
The registration plate is embedded with a plurality of target markers, and each fiducial marker is placed on the surface of the registration plate.
The registration plate is a registration plate embedded with a plurality of target markers, the plurality of target markers belong to the components of the registration plate, the fiducial markers do not belong to the components of the registration plate, and are only markers introduced for realizing the calibration of the registration plate.
The target markers and fiducial markers may be spherical, square or other shaped markers.
The registration plate is generally a three-dimensional volumetric structure including a plurality of target markers, for example, at least 4 target markers may be included, at least one of which is not coplanar with the other markers.
The individual fiducial markers may be placed on multiple sides of the registration plate surface.
The fluoroscopic image may be an image in which the fiducial marker and the target marker can be visualized in an image, such as an X-ray image, a CT (Computed Tomography) image, an MR (Magnetic Resonance) image, an ultrasound image, a PET (Positron Emission Tomography) image, and the like.
The target marker and the reference marker may be made of a material developed in at least one of the images. The sheet material of the registration plate that encloses the markers may be made of a material that does not develop or develops poorly in the images.
For example, the target markers and the fiducial markers may be steel balls, and the plate may be plastic.
Step S102: image coordinates of each reference marker and each target marker in the fluoroscopic image are detected.
The image coordinates of the marker can be represented by the geometric center, the centroid or the image coordinates of any position on the marker.
Specifically, the respective fiducial markers and the respective target markers may be detected in their respective regions in the fluoroscopic image, and then the image coordinates of the respective fiducial markers and the respective target markers may be determined based on the positional information of the detected regions in the fluoroscopic image.
In one embodiment of the present invention, when detecting the regions of the reference marker and the target marker in the fluoroscopic image, the detection may be performed by any one of the following three implementations.
In the first implementation manner, since the materials of the two markers can be known in advance, the pixel values of the two markers in the perspective image can be known in advance, so that the region where the pixel point with the pixel value known in advance is located in the perspective image is determined to be the region where the marker is located.
In the second embodiment, the region of the reference marker and the target marker in the fluoroscopic image can be detected by detecting the fluoroscopic image using a detection method for detecting the image region of the marker having the shape according to the shape of the marker.
For example, when the reference marker and the target marker are spherical markers, a circular region in the fluoroscopic image may be detected by a circle finding method, and the specified region may be determined as a region where the marker is located.
The reference marker and the target marker may have the same or different shapes, and the fluoroscopic image may be detected by different detection methods for markers having different shapes.
In addition to the above two implementations, the respective fiducial markers and the regions of the respective target markers in the fluoroscopic image may be detected by other detection methods.
In an embodiment of the present invention, an object that is the same as the reference marker or the target marker may exist in the registration plate, in this case, after the perspective image is obtained, a region where a pixel point whose pixel value is a previously known pixel value is located may be determined, and it is determined whether the shape of each determined region is the shape of the reference marker or the target marker, if so, the region is determined as the region where the marker is located, and if not, the region is determined as not.
In one embodiment of the present invention, after detecting the region of each fiducial marker and each target marker in the fluoroscopic image, for each of the fiducial markers and each target marker, the image coordinates of the marker may be determined by any one of the following three implementations.
In a first implementation manner, the coordinates of the pixel point located in the center of the area where the marker is located may be used as the image coordinates of the marker.
In the second implementation manner, the coordinates of the centroid of the marker may also be calculated, and as the image coordinates of the marker, the implementation manner of calculating the coordinates of the centroid of the marker may refer to step S102A in the embodiment shown in the subsequent fig. 4, which is not detailed here for the moment.
In a third implementation manner, the coordinates of any pixel point in the area where the marker is located may also be determined as the image coordinates of the marker.
Step S103: and obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system.
The calibration coordinate system may be manually constructed, may also be constructed according to the length, width and height of the registration plate, and may also be determined in other manners.
Further description of the above calibration coordinate system can be found in the following embodiments, and will not be detailed here.
Specifically, a calibration coordinate system where the registration plate is located may be determined first, and calibration coordinates of each fiducial marker in the calibration coordinate system may be obtained.
In one embodiment of the invention, in obtaining the calibration coordinates of the fiducial marker, the coordinates may be obtained by any one of the following three implementations.
In the first implementation manner, since the reference mark is placed on the surface of the registration plate, coordinates of the reference mark measured by a user using a measuring tool such as a ruler or a caliper may be obtained as calibration coordinates of the reference mark.
In a second implementation manner, a position sensor may be further mounted on the reference marker to obtain coordinates of the position sensor in the calibration coordinate system, and the calibration coordinates of the reference marker may be determined according to the measured sensor coordinates.
In a third implementation manner, calibration coordinates of the reference mark object measured by the existing coordinate measuring machine may also be obtained, and a specific implementation manner of the measurement by the coordinate measuring machine may be referred to step S103A in the embodiment shown in subsequent fig. 6, which will not be described in detail here.
Step S104: and determining the coordinates of each target marker in a calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
In an embodiment of the present invention, a conversion relationship between an image coordinate system in which the perspective image is located and a calibration coordinate system may be calculated, and the image coordinate of the target marker is converted to a coordinate in the calibration coordinate system according to the conversion relationship, so as to realize calibration of the registration plate. The specific implementation manner of using the transformation relationship between the two coordinate systems to realize the calibration of the registration plate can be referred to steps S104A-S104B in the embodiment shown in subsequent fig. 2, and will not be described in detail here.
In another embodiment of the present invention, since the relative position relationship between each fiducial marker and each target marker is fixed, the relative position relationship between each fiducial marker and each target marker may be calculated first, and then the coordinates of the target marker in the calibration coordinate system may be determined according to the calibration coordinates of the fiducial markers based on the calculated relative position relationship, so as to achieve calibration of the registration plate. The specific implementation manner of using the relative position relationship between the fiducial marker and the target marker to realize the calibration of the registration plate can be seen in steps S104C-S104D in the embodiment shown in the subsequent fig. 3, which will not be described in detail here.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the plurality of target markers are embedded in the calibrated registration plate, and in order to calibrate the registration plate, the reference markers are placed on the surface of the registration plate, so that when the registration plate is calibrated, not only the image coordinates of each target marker can be detected, but also the image coordinates of each reference marker can be detected, and the calibration coordinates of each reference marker can be obtained, so that the image coordinates of the target markers in the image coordinate system, the image coordinates of the reference markers and the calibration coordinates of the reference markers can be accurately converted to the coordinates in the calibration coordinate system. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
In addition, in the registration plate calibration process, the registration plate calibration can be realized only by placing a plurality of reference markers on the surface of the registration plate and according to the perspective images and the calibration coordinates of the reference markers, so that the registration plate calibration method based on the scheme is simple in steps and high in convenience, the markers included in the registration plate do not need to be mounted on the surface or preset positions of the registration plate, and the process requirements on the registration plate are low. The target marker is embedded in the registration plate, so that the risk of falling off of the marker due to the fact that the marker is mounted on the surface of the registration plate can be avoided.
The above calibration coordinate system is further explained below.
The calibration coordinate system is preset. When obtaining the above perspective image, a perspective image having the same dimension as the calibration coordinate system may be obtained, and when placing the fiducial markers on the surface of the registration plate, the number of the fiducial markers to be placed may be determined according to the dimension of the calibration coordinate system.
In one embodiment of the present invention, when the calibration coordinate system is a two-dimensional coordinate system, the fluoroscopic image is a two-dimensional image, and the number of the reference markers is at least two.
In an embodiment of the present invention, the two-dimensional perspective image may be an image obtained by parallel projecting the calibration plate, and the projection light during projection may be perpendicular to the plane where the calibration plate is located.
In the case where the calibration coordinate system is a three-dimensional coordinate system, the fluoroscopic image is a three-dimensional image, and the number of the reference markers is at least three.
In this scheme, when the calibration coordinate system is a two-dimensional coordinate system, the detected image coordinates of each reference mark, the detected image coordinates of each target mark and the detected image coordinates of each reference mark are two-dimensional coordinates, and the coordinates of the target mark in the two-dimensional calibration coordinate system can be accurately determined by using the image coordinates of at least two reference marks, the detected image coordinates of each target mark and the detected calibration coordinates of the at least two reference marks.
The reference marker and the target marker may have the same or different shapes and sizes.
In an embodiment of the invention, a size difference between the reference marker and the target marker is smaller than or equal to a preset difference.
The two markers may be of various shapes, the size difference may be expressed differently for differently shaped markers, and different difference thresholds may be preset for differently shaped markers.
For example, if the fiducial marker and the target marker are spherical markers, the size difference may be represented by a difference in radius between the two markers, and the predetermined difference may be set with respect to the radius of the spherical marker.
If the reference marker and the target marker are square markers, the size difference may be represented by a length difference, a width difference, and a height difference of the two markers, and the preset difference may be set with respect to the length, the width, and the height of the square markers.
In the scheme, the size difference between the reference mark and the target mark is smaller than or equal to the preset difference, and the shapes and the sizes of the two marks are almost the same, so that when the image coordinates of the reference mark and the target mark are detected, the image coordinates of the two marks can be detected by using the same method, the efficiency of detecting the image coordinates is improved, and the calibration efficiency of the registration plate is improved.
A specific implementation manner of the registration plate calibration using the transformation relationship between the two coordinate systems mentioned in step S104 above is described below.
In an embodiment of the present invention, referring to fig. 2, a flowchart of a second registration plate calibration method is provided, and in this embodiment, the step S104 may be implemented by the following steps S104A to S104B.
Step S104A: and determining the conversion relation between the image coordinate system where the perspective image is located and the calibration coordinate system according to the image coordinates of each reference mark object and the calibration coordinates of each reference mark object.
According to the image coordinates of each reference mark object and the calibration coordinates of each reference mark object, the conversion relation between the image coordinate system and the calibration coordinate system can be calculated through the existing coordinate conversion technology.
For example, the image coordinates of each fiducial marker and the calibration coordinates of each fiducial marker may be converted from the image coordinate system to the calibration coordinate system by calculating the amount of rotation and translation, and the conversion relationship between the image coordinate system and the calibration coordinate system may be determined based on the calculated amount of rotation and translation.
Step S104B: and converting the image coordinates of each target marker into coordinates in a calibration coordinate system based on the determined conversion relation.
For each target marker, the image coordinates of the target marker may be converted to coordinates in a calibration coordinate system based on the determined conversion relationship.
The conversion of the image coordinates in the image coordinate system into the coordinates in the calibration coordinate system can be realized by the existing coordinate conversion technology, and is not described in detail here.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the conversion relationship between the image coordinate system and the calibration coordinate system can be accurately determined according to the image coordinates of each reference mark and the calibration coordinates of each reference mark, so that the image coordinates of each target mark can be accurately converted into the coordinates in the calibration coordinate system based on the determined conversion relationship. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
A specific implementation of the calibration of the registration plate using the relative position relationship between the fiducial marker and the target marker in step S104 will be described below.
In an embodiment of the present invention, referring to fig. 3, a flowchart of a third registration plate calibration method is provided, and in this embodiment, the step S104 can be implemented by the following steps S104C to S104D.
Step S104C: and determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object.
In one embodiment of the present invention, for each target marker, a relative distance between the target marker and each fiducial marker may be calculated according to the image coordinates of the target marker and the image coordinates of each fiducial marker, so that a relative position between the fiducial marker and each target marker may be determined according to the calculated relative distances.
In another embodiment of the present invention, for each target marker, each included angle formed by the target marker and each fiducial marker may be calculated according to the image coordinates of the target marker and the image coordinates of each fiducial marker, so that the relative position between the fiducial marker and each target marker may be determined according to the calculated included angles.
Step S104D: and determining the coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
For each target marker, the coordinates of the target marker in the calibration coordinate system may be determined based on the relative position between the target marker and the respective fiducial marker, and the marker coordinates of the respective fiducial marker.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating a registration plate, according to the image coordinates of each fiducial marker and the image coordinates of each target marker, the relative position between each fiducial marker and each target marker can be accurately determined, and because the relative position between each fiducial marker and each target marker is fixed, the coordinates of each target marker in the calibration coordinate system can be accurately determined according to the determined relative position and the calibration coordinates of each fiducial marker. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
A specific implementation of the above-mentioned step S102 in which the coordinates of the centroid of the marker are used as the image coordinates of the marker will be described below.
In an embodiment of the present invention, referring to fig. 4, a flowchart of a fourth registration plate calibration method is provided, and in this embodiment, the step S102 may be implemented by the following step S102A.
Step S102A: for each of the fiducial markers and the target markers, coordinates of the centroid of the marker in the fluoroscopic image are detected as image coordinates of the marker.
In an embodiment of the present invention, for each of the fiducial markers and the target markers, the position of the centroid of the marker in the marker may be predetermined, so that after the region of the marker in the fluoroscopic image is detected, according to the predetermined position of the centroid in the marker, a pixel point corresponding to the centroid of the marker is determined in the detected region, and the coordinate of the pixel point is determined as the coordinate of the centroid of the marker.
In addition, the coordinates of the centroid of each marker can also be detected through steps S102A1-S102A2 in the embodiment shown in the subsequent fig. 5, which will not be detailed here.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibration of a registration plate, since the centroid of a marker is generally representative for the marker, the detected coordinates of the centroid of each marker are used as the image coordinates of each marker, which can improve the accuracy of the image coordinates of each marker, thereby improving the accuracy of calibration of the registration plate.
In detecting the coordinates of the centroids of the respective markers in the fluoroscopic image, the coordinates of the centroids of the respective markers may be detected through steps S102A1 to S102A2 in the subsequent embodiment shown in fig. 5, in addition to the manner provided in step S102A in the embodiment shown in fig. 4 described above.
In an embodiment of the present invention, referring to fig. 5, a flowchart of a fifth registration plate calibration method is provided, and in this embodiment, the step S102A may be implemented by the following steps S102A1 to S102 A2.
Step S102A1: the region of each marker in the fluoroscopic image is detected.
The manner of detecting the regions where the markers are located in the fluoroscopic image can be referred to step S102 in the embodiment shown in fig. 1, which is not described herein again.
Step S102A2: and for each marker, performing weighted average calculation on the coordinates of the pixel points in the area where the marker is located according to the weight coefficient of the pixel points in the area where the marker is located to obtain the calculated coordinates of the centroid of the marker, and taking the calculated coordinates as the image coordinates of the marker.
Wherein, the weight coefficient of the pixel point is determined according to the pixel value of the pixel point.
The larger the pixel value of the pixel point is, the closer the distance between the position corresponding to the pixel point in the marker and the centroid of the marker is, and the larger the weight coefficient of the pixel point is.
Specifically, for each marker, a weight coefficient of a pixel point in an area where the marker is located may be determined, then weighted average calculation is performed on coordinates of the determined pixel point, and the coordinates obtained after calculation are determined as coordinates of a centroid of the marker.
For example, if a region where a marker is located includes a pixel 1, a pixel 2, and a pixel 3, the coordinate of the pixel 1 is (x 1, y1, z 1), the weight coefficient is a1, the coordinate of the pixel 2 is (x 2, y2, z 2), the weight coefficient is a2, the coordinate of the pixel 3 is (x 3, y3, z 3), and the weight coefficient is a3, the coordinates of the three pixels are weighted and averaged, and the obtained x-axis coordinate of the centroid of the marker is (a 1 x1+ a2 x2+ a3 x 3)/3,y is (a 1 y1+ a2 y2+ a3 x 3)/3,z is (a 1 x z1+ a2 z2+ a 3)/3.
In addition, when determining the weight coefficient of a pixel point in the region where the marker is located, the weight coefficient of each pixel point in the region may be determined, or the weight coefficients of some pixel points in the region may also be determined, for example, the weight coefficient of one pixel point may be determined every certain number of pixel points.
In one embodiment of the present invention, the pixel value of a pixel point in the region where the marker is located may be used as the weighting coefficient of the pixel point, and the coordinates of the centroid of the marker are calculated by the following expression:
Figure BDA0003737949110000121
wherein P is the coordinate of the centroid, K is the total number of pixel points in the region where the marker is located, K is the kth pixel point in the region where the marker is located, and m k Is the pixel value, Q, of the kth pixel k Is the coordinate of the kth pixel point.
If P is the x-axis coordinate of the centroid in the preset image coordinate system, Q k Is the x-axis coordinate of the kth pixel point in the preset image coordinate system, if P is the y-axis coordinate of the centroid in the preset image coordinate system, Q is k Is the y-axis coordinate of the kth pixel point in the preset image coordinate system, and if P is the z-axis coordinate of the centroid in the preset image coordinate system, Q is k And the z-axis coordinate of the kth pixel point in a preset image coordinate system.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibration of the registration plate, the pixel value of each pixel point in the region where the marker is located in the fluoroscopic image can usually reflect the weight distribution of the marker, so that after the region where the marker is located in the fluoroscopic image is detected, the weight coefficient of the pixel point can be accurately determined according to the pixel value of the pixel point in the detected region, and thus, the weighted average calculation is performed on the coordinates of the pixel point in the detected region according to the weight coefficient of the pixel point in the detected region, the coordinates of the centroid of the marker can be accurately calculated, and the coordinates of the centroid of the marker are taken as the coordinates of the marker, so that the calibration accuracy of the registration plate can be improved.
In obtaining the calibration coordinates of the reference mark, in addition to the manner mentioned in step S103 in the embodiment shown in fig. 1, the calibration coordinates of the reference mark may be obtained in step S103A in the embodiment shown in fig. 6.
In an embodiment of the present invention, referring to fig. 6, a schematic flow chart of a sixth registration plate calibration method is provided, in this embodiment, a preset calibration coordinate system is: the above step S103 can be realized by the following step S103A in the coordinate system corresponding to the coordinate measuring machine.
Step S103A: and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
In an embodiment of the present invention, the coordinate measuring apparatus is a three-dimensional coordinate measuring apparatus for calibrating the registration plate.
When the coordinate measuring machine is used for measuring the coordinates of each reference mark object, the registration plate can be placed on a measuring platform of the coordinate measuring machine, and a measuring tool of the coordinate measuring machine is contacted with each reference mark object.
Specifically, a coordinate system not corresponding to the coordinate measuring apparatus in the calibration coordinate system may be preset, and after the coordinate measuring apparatus measures the coordinates of each reference mark in the coordinate system corresponding to the apparatus, the measured coordinates of each reference mark may be obtained and used as the calibration coordinates of each reference mark.
Therefore, when the scheme provided by the embodiment of the invention is applied to calibrating the registration plate, the coordinate measuring instrument can accurately measure the coordinates of each reference mark object in the coordinate system corresponding to the coordinate measuring instrument, so that under the condition that the coordinate system is the coordinate system corresponding to the coordinate measuring instrument, the calibration coordinates of each reference mark object can be accurately obtained by obtaining the coordinates obtained by measuring each reference mark object by the coordinate measuring instrument, and the coordinates of each target mark object in the calibration coordinate system can be accurately determined based on the calibration coordinates of each reference mark object.
Corresponding to the registration plate calibration method, the embodiment of the invention also provides a registration plate calibration device.
In one embodiment of the present invention, referring to fig. 7, a schematic structural diagram of a first registration plate calibration apparatus is provided, the apparatus including:
an image obtaining module 701, configured to obtain a perspective image including a plurality of fiducial markers and a registration plate, where a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on a surface of the registration plate;
a coordinate detection module 702, configured to detect image coordinates of each fiducial marker and each target marker in the fluoroscopic image;
a coordinate obtaining module 703, configured to obtain calibration coordinates of each fiducial marker in a preset calibration coordinate system;
and a coordinate determination module 704, configured to determine coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each fiducial marker, and the calibration coordinates of each fiducial marker.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the plurality of target markers are embedded in the calibrated registration plate, and in order to calibrate the registration plate, the reference markers are placed on the surface of the registration plate, so that when the registration plate is calibrated, not only the image coordinates of each target marker can be detected, but also the image coordinates of each reference marker can be detected, and the calibration coordinates of each reference marker can be obtained, so that the image coordinates of the target markers in the image coordinate system, the image coordinates of the reference markers and the calibration coordinates of the reference markers can be accurately converted to the coordinates in the calibration coordinate system. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
In addition, in the registration plate calibration process, the registration plate calibration can be realized only by placing a plurality of reference markers on the surface of the registration plate and according to the perspective images and the calibration coordinates of the reference markers, so that the registration plate calibration method applied to the scheme is simple in step and high in convenience, the markers included in the registration plate are not required to be installed on the surface or preset positions of the registration plate, and the process requirements on the registration plate are low. The target marker is embedded in the registration plate, so that the risk of falling off of the marker caused by the fact that the marker is installed on the surface of the registration plate can be avoided.
In an embodiment of the present invention, the coordinate determining module 704 is specifically configured to:
determining a conversion relation between an image coordinate system of the perspective image and the calibration coordinate system according to the image coordinate of each reference mark object and the calibration coordinate of each reference mark object;
and converting the image coordinates of each target marker into coordinates in the calibration coordinate system based on the determined conversion relation.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the conversion relationship between the image coordinate system and the calibration coordinate system can be accurately determined according to the image coordinates of each reference mark and the calibration coordinates of each reference mark, so that the image coordinates of each target mark can be accurately converted into the coordinates in the calibration coordinate system based on the determined conversion relationship. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
In an embodiment of the present invention, the coordinate determining module 704 is specifically configured to:
determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object;
and determining coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating a registration plate, according to the image coordinates of each fiducial marker and the image coordinates of each target marker, the relative position between each fiducial marker and each target marker can be accurately determined, and because the relative position between each fiducial marker and each target marker is fixed, the coordinates of each target marker in the calibration coordinate system can be accurately determined according to the determined relative position and the calibration coordinates of each fiducial marker. Therefore, the registration plate calibration accuracy can be improved by applying the registration plate calibration scheme provided by the embodiment of the invention.
In an embodiment of the present invention, referring to fig. 8, a schematic structural diagram of a second registration plate calibration apparatus is provided, in this embodiment, the coordinate detection module 702 includes:
a centroid detection submodule 702A, configured to detect, for each of the fiducial markers and the target markers, coordinates of a centroid of the marker in the fluoroscopic image as image coordinates of the marker.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibration of a registration plate, since the centroid of a marker is generally representative for the marker, the detected coordinates of the centroid of each marker are used as the image coordinates of each marker, which can improve the accuracy of the image coordinates of each marker, thereby improving the accuracy of calibration of the registration plate.
In an embodiment of the present invention, the centroid detecting submodule 702A is specifically configured to:
detecting the area of each marker in the perspective image;
and for each marker, performing weighted average calculation on the coordinates of the pixel points in the area where the marker is located according to the weight coefficient of the pixel points in the area where the marker is located to obtain the calculated coordinates of the centroid of the marker, wherein the weight coefficient of the pixel points is determined according to the pixel value of the pixel points.
Therefore, when the scheme provided by the embodiment of the invention is applied to calibration of the registration plate, the pixel value of each pixel point in the region where the marker is located in the perspective image can usually reflect the weight distribution of the marker, and therefore, after the region where the marker is located in the perspective image is detected, the weight coefficient of the pixel point can be accurately determined according to the pixel value of the pixel point in the detected region, so that the coordinates of the pixel point in the detected region can be subjected to weighted average calculation according to the weight coefficient of the pixel point in the detected region, the coordinates of the centroid of the marker can be accurately calculated, the coordinates of the centroid of the marker can be used as the coordinates of the marker, and the calibration accuracy of the registration plate can be improved.
In an embodiment of the present invention, the preset calibration coordinate system is: a coordinate system corresponding to the coordinate measuring instrument;
the coordinate obtaining module 703 is specifically configured to:
and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
As can be seen from the above, when the scheme provided by the embodiment of the present invention is applied to calibrating the registration plate, the coordinate measuring apparatus can accurately measure the coordinates of each reference mark object in the coordinate system corresponding to the coordinate measuring apparatus, so that in the case that the coordinate system is calibrated in the coordinate system corresponding to the coordinate measuring apparatus, the calibration coordinates of each reference mark object can be accurately obtained by obtaining the coordinates obtained by the coordinate measuring apparatus by measuring each reference mark object, and thus, the coordinates of each target mark object in the calibration coordinate system can be accurately determined based on the calibration coordinates of each reference mark object.
In an embodiment of the invention, in the case that the calibration coordinate system is a two-dimensional coordinate system, the perspective image is a two-dimensional image, and the number of the fiducial markers is at least two;
and under the condition that the calibration coordinate system is a three-dimensional coordinate system, the perspective image is a three-dimensional image, and the number of the fiducial markers is at least three.
In this scheme, when the calibration coordinate system is a two-dimensional coordinate system, the detected image coordinates of each reference mark, the detected image coordinates of each target mark and the detected image coordinates of each reference mark are two-dimensional coordinates, and the coordinates of the target mark in the two-dimensional calibration coordinate system can be accurately determined by using the image coordinates of at least two reference marks, the detected image coordinates of each target mark and the detected calibration coordinates of the at least two reference marks.
In one embodiment of the present invention, the size difference between the fiducial marker and the target marker is less than or equal to a predetermined difference.
In the scheme, the size difference between the reference mark and the target mark is smaller than or equal to the preset difference, and the shapes and the sizes of the two marks are almost the same, so that when the image coordinates of the reference mark and the target mark are detected, the image coordinates of the two marks can be detected by using the same method, the efficiency of detecting the image coordinates is improved, and the calibration efficiency of the registration plate is improved.
An embodiment of the present invention further provides an electronic device, as shown in fig. 9, which includes a processor 901, a communication interface 902, a memory 903, and a communication bus 904, where the processor 901, the communication interface 902, and the memory 903 complete mutual communication through the communication bus 904,
a memory 903 for storing computer programs;
the processor 901 is configured to implement the following steps when executing the program stored in the memory 903:
obtaining a perspective image containing a plurality of fiducial markers and a registration plate, wherein a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on the surface of the registration plate;
detecting image coordinates of each reference mark object and each target mark object in the perspective image;
obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system;
and determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
The processor 901 executes the program stored in the memory 903 to implement other schemes for calibrating the registration plate, which are the same as those mentioned in the foregoing method embodiments and are not described herein again.
The communication bus mentioned in the electronic device may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown, but this is not intended to represent only one bus or type of bus.
The communication interface is used for communication between the electronic equipment and other equipment.
The Memory may include a Random Access Memory (RAM) or a Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the processor.
The Processor may be a general-purpose Processor, including a Central Processing Unit (CPU), a Network Processor (NP), and the like; but also Digital Signal Processors (DSPs), application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components.
In a further embodiment of the present invention, a computer-readable storage medium is further provided, in which a computer program is stored, and the computer program, when executed by a processor, implements the steps of any of the registration plate calibration methods described above.
In yet another embodiment, a computer program product containing instructions is also provided, which when run on a computer, causes the computer to perform any of the registration plate calibration methods of the above embodiments.
In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to be performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), among others.
It is noted that, herein, relational terms such as first and second, and the like may be 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 a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus, the electronic device, the computer-readable storage medium, and the computer program product embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiments.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (18)

1. A registration plate calibration method, the method comprising:
obtaining a perspective image containing a plurality of fiducial markers and a registration plate, wherein a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on the surface of the registration plate;
detecting image coordinates of each reference mark object and each target mark object in the perspective image;
obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system;
and determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
2. The method of claim 1, wherein determining coordinates of each target marker in the calibration coordinate system based on the image coordinates of each target marker, the image coordinates of each fiducial marker, and the calibration coordinates of each fiducial marker comprises:
determining a conversion relation between an image coordinate system where the perspective image is located and the calibration coordinate system according to the image coordinate of each reference mark and the calibration coordinate of each reference mark;
and converting the image coordinates of each target marker into coordinates in the calibration coordinate system based on the determined conversion relation.
3. The method of claim 1, wherein determining coordinates of each target marker in the calibration coordinate system based on the image coordinates of each target marker, the image coordinates of each fiducial marker, and the calibration coordinates of each fiducial marker comprises:
determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object;
and determining coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
4. The method of any of claims 1-3, wherein said detecting image coordinates of each fiducial marker and each target marker in the fluoroscopic image comprises:
for each of the respective fiducial markers and the respective target markers, coordinates of a centroid of the marker in the fluoroscopic image are detected as image coordinates of the marker.
5. The method of claim 4, wherein said detecting coordinates of a centroid of the marker in the fluoroscopic image comprises:
detecting the area of the marker in the perspective image;
and performing weighted average calculation on the coordinates of the pixel points in the detected area according to the weight coefficient of the pixel points in the detected area to obtain the calculated coordinates of the centroid of the marker, wherein the weight coefficient of the pixel point is determined according to the pixel value of the pixel point.
6. A method according to any one of claims 1-3, wherein the preset calibration coordinate system is: a coordinate system corresponding to the coordinate measuring instrument;
the obtaining of the calibration coordinates of each reference mark under the preset calibration coordinate system includes:
and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
7. The method according to any one of claims 1 to 3,
under the condition that the calibration coordinate system is a two-dimensional coordinate system, the perspective image is a two-dimensional image, and the number of the reference markers is at least two;
and under the condition that the calibration coordinate system is a three-dimensional coordinate system, the perspective image is a three-dimensional image, and the number of the fiducial markers is at least three.
8. The method of any one of claims 1-3, wherein the difference in size between the fiducial marker and the target marker is less than or equal to a preset difference.
9. A registration plate calibration apparatus, the apparatus comprising:
the image acquisition module is used for acquiring a perspective image containing a plurality of fiducial markers and a registration plate, wherein a plurality of target markers are embedded in the registration plate, and each fiducial marker is placed on the surface of the registration plate;
a coordinate detection module for detecting image coordinates of each reference mark object and each target mark object in the perspective image;
the coordinate obtaining module is used for obtaining the calibration coordinates of each reference mark object under a preset calibration coordinate system;
and the coordinate determination module is used for determining the coordinates of each target marker in the calibration coordinate system according to the image coordinates of each target marker, the image coordinates of each reference marker and the calibration coordinates of each reference marker.
10. The apparatus of claim 9, wherein the coordinate determination module is specifically configured to:
determining a conversion relation between an image coordinate system of the perspective image and the calibration coordinate system according to the image coordinate of each reference mark object and the calibration coordinate of each reference mark object;
and converting the image coordinates of each target marker into coordinates in the calibration coordinate system based on the determined conversion relation.
11. The apparatus of claim 9, wherein the coordinate determination module is specifically configured to:
determining the relative position between each reference mark object and each target mark object according to the image coordinates of each reference mark object and the image coordinates of each target mark object;
and determining coordinates of each target marker in the calibration coordinate system according to the calibration coordinates of each reference marker based on the determined relative position.
12. The apparatus according to any one of claims 9-11, wherein the coordinate detection module comprises:
and the mass center detection sub-module is used for detecting the coordinates of the mass center of each marker in the perspective image as the image coordinates of each marker aiming at each reference marker and each marker in each target marker.
13. The apparatus of claim 12, wherein the centroid detection submodule is specifically configured to:
detecting the area of the marker in the perspective image;
and performing weighted average calculation on the coordinates of the pixel points in the detected area according to the weight coefficients of the pixel points in the detected area to obtain the calculated coordinates of the centroid of the marker, wherein the weight coefficients of the pixel points are determined according to the pixel values of the pixel points.
14. The apparatus according to any one of claims 9-11, wherein the preset calibration coordinate system is: a coordinate system corresponding to the coordinate measuring instrument;
the coordinate obtaining module is specifically configured to:
and obtaining coordinates obtained by measuring each reference mark by the coordinate measuring instrument, and taking the coordinates as the calibration coordinates of each reference mark in a preset calibration coordinate system.
15. The apparatus according to any one of claims 9-11,
under the condition that the calibration coordinate system is a two-dimensional coordinate system, the perspective image is a two-dimensional image, and the number of the reference mark objects is at least two;
and under the condition that the calibration coordinate system is a three-dimensional coordinate system, the perspective image is a three-dimensional image, and the number of the fiducial markers is at least three.
16. The device of any one of claims 9-11, wherein a difference in size between the fiducial marker and the target marker is less than or equal to a preset difference.
17. An electronic device is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor and the communication interface are used for realizing mutual communication by the memory through the communication bus;
a memory for storing a computer program;
a processor for implementing the method steps of any of claims 1 to 8 when executing a program stored in the memory.
18. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, which computer program, when being executed by a processor, carries out the method steps of any one of the claims 1-8.
CN202210806537.1A 2022-07-08 2022-07-08 Registration plate calibration method and device Pending CN115294028A (en)

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