CN106600649A - Camera self-calibration method based on two-dimensional mark code - Google Patents
Camera self-calibration method based on two-dimensional mark code Download PDFInfo
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- CN106600649A CN106600649A CN201611118239.4A CN201611118239A CN106600649A CN 106600649 A CN106600649 A CN 106600649A CN 201611118239 A CN201611118239 A CN 201611118239A CN 106600649 A CN106600649 A CN 106600649A
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Abstract
The invention discloses a camera self-calibration method based on a two-dimensional mark code. The method comprises the following steps of setting a two-dimensional target with a mark code; carrying out image acquisition on the two-dimensional target and acquiring a two-dimensional target image group possessing the mark code; detecting the mark code in the two-dimensional target image group and matching to a two-dimensional target image; determining a two-dimensional target base image and calculating an inner parameter matrix and an outer parameter matrix of an image acquisition apparatus; optimizing the inner parameter matrix and the outer parameter matrix of the image acquisition apparatus; and adding the image acquisition apparatus and calculating inner and outer parameters and three-dimensional point cloud of the image acquisition apparatus. In the invention, through setting the two-dimensional target possessing the mark code, the image acquisition apparatus is calibrated and technical problems that manufacturing of a three-dimensional target is difficult, an accuracy requirement is high and a self-calibration result precision is poor in a traditional calibration technology are solved.
Description
Technical field
The present invention relates to dimensional Modeling Technology field, and in particular to a kind of Camera Self-Calibration side based on two-dimensional marker code
Method.
Background technology
In the field based on photo three-dimensional reconstruction, how by two dimensional image recover target object three dimensions geometry with
And camera motion parameter is always the focus in the field.At present conventional scaling method can be divided three classes：Traditional scaling method,
Active vision method and Camera Self-Calibration method.Traditional scaling method is needed using the demarcation thing of known three-dimensional geometric information, is obtained
The calibration result for arriving is more accurate, however it is necessary that high accuracy three-dimensional target, greatly, cost is also higher for manufacture difficulty；Actively regard
Feel some movable informations of camera known to scaling method needs, the advantage of this kind of calibration algorithm is due to the motion of known portions camera
Information, therefore can be with linear solution camera model parameter, algorithm robustness is higher, but complex operation, is difficult in actual applications
Accurate movement camera；Camera Self-Calibration method is that target object is repeatedly shot in a certain static scene, or multiple phases
Machine shoots simultaneously to target, is demarcated using the mutual restriction relation between image sequence, there is the very wide range of application sent out, but smart
Degree is poor.
The content of the invention
The technical problem to be solved is, for above-mentioned deficiency of the prior art, to disclose a kind of based on two
The Camera Self-Calibration method of dimension flag code, making hardly possible, the required precision for solving three-dimensional target in traditional calibration technique is high, and from
The technical problem of scaling method result low precision.
The technical solution adopted for the present invention to solve the technical problems is：A kind of Camera Self-Calibration based on two-dimensional marker code
Method, it is characterised in that comprise the following steps：
It is provided with the two-dimensional target of flag code；
Image acquisition is carried out to two-dimensional target, the two-dimensional target image sets with flag code are obtained；
Flag code in two-dimensional target image sets is detected and two-dimensional target image is matched；
Determine two-dimensional target base image, and calculate the Intrinsic Matrix and outer parameter matrix of image collecting device；
Intrinsic Matrix and outer parameter matrix to image collecting device is optimized；
Increase image collecting device and calculate the inside and outside parameter and three-dimensional point cloud of the image collecting device.
Further, it is described that multi-angle image collection is carried out to two-dimensional target, obtain the two-dimensional target figure with flag code
As group；Specifically include：The collection of multiple images is carried out to two-dimensional target by image collecting device, with flag code two are formed
Dimension target image group.
Further, described image harvester carries out multi-angled shooting and is had using a camera to two-dimensional target
The two-dimensional target image sets of flag code.
Further, described image harvester obtains with flag code two simultaneously using multiple cameras to two-dimensional target
Dimension target image group.
Further, the flag code in the image sets to two-dimensional target is detected and two-dimensional target image carried out
Match somebody with somebody, specifically include：Flag code on each two-dimensional target image in two-dimensional target image sets is detected, is obtained per a two dimension
Four angular coordinates of the numbering of flag code and flag code on target image；And to the two-dimensional target figure with same tag code
As being matched.
Further, the determination two-dimensional target base image, and calculate the Intrinsic Matrix of image collecting device and outer
Parameter matrix, specifically includes：Two two-dimensional targets for selecting the quantity of labelling code-phase matching on all two-dimensional target images most
Image, according to the angular coordinate meter of flag code matching in the initial internal parameter and two two-dimensional target images of image collecting device
Calculate the basis matrix of two two-dimensional target images；The basis matrix of two two-dimensional target images is decomposed, image is obtained and is adopted
The Intrinsic Matrix of acquisition means and outer parameter matrix.
Further, the Intrinsic Matrix and outer parameter matrix to image collecting device is optimized；Specially：Adopt
With heterogeneous linear optimization Levenberg Marquardt methods and minimum angle point re-projection error algorithm to Intrinsic Matrix and outer ginseng
Matrix number is optimized, the camera intrinsic parameter and outer parameter after being optimized.
Further, it is described to increase image collecting device and calculate the inside and outside parameter and three-dimensional point of the image collecting device
Cloud, specifically includes, and the image collecting device of increase obtains corresponding two-dimensional target image sets and determines two-dimensional target base image,
Obtain the three-dimensional point of the intrinsic parameter, outer parameter and the corresponding flag code of the image collecting device of the image collecting device of the increase
Cloud.
The present invention has compared with prior art advantages below：
The present invention is demarcated by arranging the two-dimensional target with flag code to image collecting device, solves tradition mark
Determine the technical problem of the making hardly possible, precise requirements height and self-calibration result low precision of three-dimensional target in technology.Image collector
Put and multiple two-dimensional target images are obtained to two-dimensional target, according to the flag code number of matches on two-dimensional target image, it is determined that two-dimentional
Target base image, the angular coordinate of the flag code in two-dimensional target base image calculates the parameter letter of image collecting device
Breath, obtains the Intrinsic Matrix and outer parameter matrix of image collecting device, then according to the initial intrinsic parameter of image collecting device
Intrinsic Matrix and outer parameter matrix to the image collecting device is optimized, and obtains the demarcation letter of the image collecting device
Breath, then increases image collecting device, and increased image collecting device is demarcated according to above-mentioned step, until final complete
Into the demarcation of all image collecting devices.
Two-dimensional target is to print the flag code with identifier, and using the square marks code with four angle points, it is right to be easy to
The identification of flag code, arranges unique identifier on flag code, realize the matching to characteristic point, and each flag code is using internal volume
The ID of code is determined unique identifier, it is entirely avoided the characteristic point of erroneous matching, improves the robustness of calibration system.
Description of the drawings
Fig. 1 is a kind of Camera Self-Calibration method flow diagram based on two-dimensional marker code proposed by the present invention.
Specific embodiment
Below in conjunction with the accompanying drawings and embodiment describes the specific embodiment of the invention：
It is a kind of Camera Self-Calibration method flow diagram based on two-dimensional marker code proposed by the present invention referring to Fig. 1.
As shown in figure 1, a kind of Camera Self-Calibration method based on two-dimensional marker code, it is characterised in that comprise the following steps：
Step 101, is provided with the two-dimensional target of flag code；
Step 102, image acquisition is carried out to two-dimensional target, obtains the two-dimensional target image sets with flag code；
Step 103, is detected to the flag code in two-dimensional target image sets and two-dimensional target image is matched；
Step 104, determines two-dimensional target base image, and calculates the Intrinsic Matrix and outer parameter square of image collecting device
Battle array；
Step 105, the Intrinsic Matrix and outer parameter matrix to image collecting device is optimized；
Step 106, increases image collecting device and calculates the inside and outside parameter and three-dimensional point cloud of the image collecting device.
By arranging the two-dimensional target with flag code in the embodiment of the present invention, image collecting device is demarcated, solved
The technical problem of the making hardly possible, precise requirements height and self-calibration result low precision of three-dimensional target in certainly traditional calibration technique.Figure
As harvester obtains multiple two-dimensional target images to two-dimensional target, according to the flag code number of matches on two-dimensional target image,
Determine two-dimensional target base image, the angular coordinate of the flag code in two-dimensional target base image calculates image collecting device
Parameter information, according to the initial intrinsic parameter of image collecting device obtain image collecting device Intrinsic Matrix and outer parameter square
Battle array, then the Intrinsic Matrix to the image collecting device and outer parameter matrix are optimized, and obtain the image collecting device
Calibration information, then increases image collecting device, and increased image collecting device is demarcated according to above-mentioned step, until
It is finally completed the demarcation of all image collecting devices.
Flag code can be using the quadricorn square marks of tool, and the square marks can adopt filled black, inside it
Setting is easy to the binary identifier for recognizing, multiple flag codes to constitute binary matrix, be conducive to adopting using dark border
By quick detection in the image of collection, binary identification symbol is corresponded with flag code.
Two-dimensional target is to arrange multiple flag codes in one plane, adopts and is uniformly distributed, thus it is possible to vary flag code
Fill color, between adjacent marker code space is arranged, and is easy to the detection of flag code angular coordinate, it is preferred that around flag code
The white frame of 1cm is set, there is the interval that can be distinguished between such adjacent marker code.
Unique identifier is set on flag code, the matching to characteristic point is realized, each flag code is using in-line coding
ID is determined unique identifier, it is entirely avoided the characteristic point of erroneous matching, improves the robustness of calibration system.
In a step 102, it is described that multi-angle image collection is carried out to two-dimensional target, obtain the two-dimensional target with flag code
Image sets；Specifically include：The collection of multiple images is carried out to two-dimensional target by image collecting device, is formed with flag code
Two-dimensional target image sets.
In a step 102, can adopt as the image collecting device for carrying out multi-angle image collection to two-dimentional target first
The collection of multiple images is carried out around target with a camera, then to gather its flag code of image detection and match.
In a step 102, can adopt as the image collecting device for carrying out multi-angle image collection to two-dimentional target first
Shot multiple two-dimensional target images with flag code simultaneously to two-dimensional target with two cameras, as subsequent step can
Select image.
No matter carrying out multi-angle image using a camera for multi-angle image collection is carried out to two-dimentional target first
Collection, or the collection of two-dimensional target image is carried out to two-dimensional target using two cameras or multiple cameras, due at the beginning of camera
Beginning parameter is, it is known that can determine the internal reference of camera according to the initial intrinsic parameter of the two-dimensional target image information and camera that select
Matrix number and outer parameter matrix, the so optimization for later stage camera parameter provide basis, while can calculate in two-dimensional target
The three-dimensional point cloud of flag code, the so demarcation for follow-up other image collecting devices provide basis, so can wait to mark to multiple
Determine image collecting device to be screened, select the two-dimensional target image and the figure for adopting first captured by other image collecting devices
As the most image collecting device of the three-dimensional point cloud number of matches of harvester acquisition, the image acquisition is calculated according to the method described above
The internal reference of device is and outer parameter, and obtains the three-dimensional point cloud corresponding to the flag code taken by the image collecting device；According to
Secondary circulation, until completing the inside and outside parameter of all image collecting devices and the three-dimensional point cloud of all flag codes.
In step 103, the flag code in the image sets to two-dimensional target is detected and two-dimensional target image is entered
Row matching, specifically includes：Flag code on each two-dimensional target image in two-dimensional target image sets is detected, obtain per
Four angular coordinates of the numbering of flag code and flag code on two-dimensional target image；And to the two-dimentional target with same tag code
Logo image is matched.
The flag code with identifier is printed in two-dimensional target, using the square marks code with four angle points, it is right to be easy to
The identification of flag code, while arranging unique identifier on flag code, is easy to match flag code, improves stated accuracy.
At step 104, it is described determination two-dimensional target base image, and calculate image collecting device Intrinsic Matrix and
Outer parameter matrix, specifically includes：Two two-dimentional targets for selecting the quantity of labelling code-phase matching on all two-dimensional target images most
Logo image, according to the angular coordinate of flag code matching in the initial internal parameter and two two-dimensional target images of image collecting device
Calculate the basis matrix of two two-dimensional target images；The basis matrix of two two-dimensional target images is decomposed, image is obtained
The Intrinsic Matrix of harvester and outer parameter matrix.
The intrinsic parameter of image collecting device is the initiation parameter of image collecting device, and such as focal length, principal point coordinate etc. lead to
The intrinsic parameter information and flag code coordinate information for crossing image collecting device obtains the Intrinsic Matrix and outer ginseng of image collecting device
Matrix number.
In step 105, the Intrinsic Matrix and outer parameter matrix to image collecting device is optimized；Specifically
For：Using heterogeneous linear optimization Levenberg Marquardt methods and minimum angle point re-projection error algorithm to Intrinsic Matrix
It is optimized with outer parameter matrix, the camera intrinsic parameter and outer parameter after being optimized.
In step 106, it is described to increase image collecting device and calculate the inside and outside parameter and three of the image collecting device
Dimension point cloud, specifically includes, and the image collecting device of increase obtains corresponding two-dimensional target image sets and determines two-dimensional target basis
Image, obtains intrinsic parameter, outer parameter and the corresponding flag code of the image collecting device of the image collecting device of the increase
Three-dimensional point cloud.
The present invention is demarcated first to an image collecting device or two image collecting devices, and figure is then increased successively
As harvester, increased image collecting device is demarcated according to flow process is demarcated first, so as to obtain all image acquisition
The calibration information of device, and the three-dimensional point cloud of two-dimensional target is calculated according to the calibration information of image collecting device, obtain
The three-dimensional point cloud of flag code in two-dimensional target, is easy to process of the later stage to view data, such as to other image collecting devices
Demarcation and the process of shooting image information.
The preferred embodiment for the present invention is explained in detail above in conjunction with accompanying drawing, but the invention is not restricted to above-mentioned enforcement
Mode, in the ken that those of ordinary skill in the art possess, can be with the premise of without departing from present inventive concept
Make a variety of changes.
Many other changes and remodeling can be made without departing from the spirit and scope of the present invention.It should be appreciated that the present invention is not
It is limited to specific embodiment, the scope of the present invention is defined by the following claims.
Claims (8)
1. a kind of Camera Self-Calibration method based on two-dimensional marker code, it is characterised in that include：Following steps：
It is provided with the two-dimensional target of flag code；
Image acquisition is carried out to two-dimensional target, the two-dimensional target image sets with flag code are obtained；
Flag code in two-dimensional target image sets is detected and two-dimensional target image is matched；
Determine two-dimensional target base image, and calculate the Intrinsic Matrix and outer parameter matrix of image collecting device；
Intrinsic Matrix and outer parameter matrix to image collecting device is optimized；
Increase image collecting device and calculate the inside and outside parameter and three-dimensional point cloud of the image collecting device.
2. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 1, it is characterised in that described right
Two-dimensional target carries out multi-angle image collection, obtains the two-dimensional target image sets with flag code；Specifically include：Adopted by image
Acquisition means carry out the collection of multiple images to two-dimensional target, form the two-dimensional target image sets with flag code.
3. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 2, it is characterised in that the figure
The two-dimensional target image sets with flag code are obtained as harvester carries out multi-angled shooting to two-dimensional target using a camera.
4. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 2, it is characterised in that the figure
As simultaneously harvester obtains the two-dimensional target image sets with flag code using multiple cameras to two-dimensional target.
5. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 1, it is characterised in that described right
Flag code in two-dimensional target image sets is detected and two-dimensional target image is matched, specifically included：To two-dimensional target
Flag code in image sets on each two-dimensional target image detected, obtains the numbering of flag code on every two-dimensional target image
And four angular coordinates of flag code；And the two-dimensional target image with same tag code is matched.
6. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 1, it is characterised in that it is described really
Determine two-dimensional target base image, and calculate the Intrinsic Matrix and outer parameter matrix of image collecting device, specifically include：Select institute
There are two most two-dimensional target images of the quantity of labelling code-phase matching on two-dimensional target image, according to the first of image collecting device
The angular coordinate of flag code matching calculates the basis of two two-dimensional target images on beginning inner parameter and two two-dimensional target images
Matrix；The basis matrix of two two-dimensional target images is decomposed, the Intrinsic Matrix of image collecting device and outer is obtained
Parameter matrix.
7. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 1, it is characterised in that described right
The Intrinsic Matrix of image collecting device and outer parameter matrix are optimized；Specially：Using heterogeneous linear optimization Levenberg
Marquardt methods and minimum angle point re-projection error algorithm are optimized to Intrinsic Matrix and outer parameter matrix, obtain excellent
Camera intrinsic parameter and outer parameter after change.
8. a kind of Camera Self-Calibration method based on two-dimensional marker code according to claim 1, it is characterised in that the increasing
Plus image collecting device and the inside and outside parameter and three-dimensional point cloud of the image collecting device are calculated, specifically include, the image of increase
Harvester obtains corresponding two-dimensional target image sets and determines two-dimensional target base image, obtains the image collector of the increase
The three-dimensional point cloud of the intrinsic parameter, outer parameter and the corresponding flag code of the image collecting device put.
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| CN111064864A (en) * | 2018-10-17 | 2020-04-24 | 杭州海康慧影科技有限公司 | Method and device for setting distortion correction parameters and endoscope system |
| CN111311690A (en) * | 2020-02-19 | 2020-06-19 | 深圳蚂里奥技术有限公司 | Calibration method and device of depth camera, terminal and computer storage medium |
| WO2023173972A1 (en) * | 2022-03-18 | 2023-09-21 | 华为技术有限公司 | Camera intrinsic calibration method and apparatus |
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| CN108010084A (en) * | 2017-11-20 | 2018-05-08 | 深圳市云之梦科技有限公司 | A kind of depth camera is rebuild and method, system, the equipment of automatic Calibration |
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