Visual Servoing Platform  version 3.5.1 under development (2023-09-22)
vpDetectorAprilTag Class Reference

#include <visp3/detection/vpDetectorAprilTag.h>

+ Inheritance diagram for vpDetectorAprilTag:

Public Types

enum  vpAprilTagFamily {
  TAG_36h11 , TAG_36h10 , TAG_36ARTOOLKIT , TAG_25h9 ,
  TAG_25h7 , TAG_16h5 , TAG_CIRCLE21h7 , TAG_CIRCLE49h12 ,
  TAG_CUSTOM48h12 , TAG_STANDARD41h12 , TAG_STANDARD52h13
}
 
enum  vpPoseEstimationMethod {
  HOMOGRAPHY , HOMOGRAPHY_VIRTUAL_VS , DEMENTHON_VIRTUAL_VS , LAGRANGE_VIRTUAL_VS ,
  BEST_RESIDUAL_VIRTUAL_VS , HOMOGRAPHY_ORTHOGONAL_ITERATION
}
 

Public Member Functions

 vpDetectorAprilTag (const vpAprilTagFamily &tagFamily=TAG_36h11, const vpPoseEstimationMethod &poseEstimationMethod=HOMOGRAPHY_VIRTUAL_VS)
 
 vpDetectorAprilTag (const vpDetectorAprilTag &o)
 
vpDetectorAprilTagoperator= (vpDetectorAprilTag o)
 
virtual ~vpDetectorAprilTag ()
 
bool detect (const vpImage< unsigned char > &I)
 
bool detect (const vpImage< unsigned char > &I, double tagSize, const vpCameraParameters &cam, std::vector< vpHomogeneousMatrix > &cMo_vec, std::vector< vpHomogeneousMatrix > *cMo_vec2=NULL, std::vector< double > *projErrors=NULL, std::vector< double > *projErrors2=NULL)
 
void displayFrames (const vpImage< unsigned char > &I, const std::vector< vpHomogeneousMatrix > &cMo_vec, const vpCameraParameters &cam, double size, const vpColor &color, unsigned int thickness=1) const
 
void displayFrames (const vpImage< vpRGBa > &I, const std::vector< vpHomogeneousMatrix > &cMo_vec, const vpCameraParameters &cam, double size, const vpColor &color, unsigned int thickness=1) const
 
void displayTags (const vpImage< unsigned char > &I, const std::vector< std::vector< vpImagePoint > > &tagsCorners, const vpColor &color=vpColor::none, unsigned int thickness=1) const
 
void displayTags (const vpImage< vpRGBa > &I, const std::vector< std::vector< vpImagePoint > > &tagsCorners, const vpColor &color=vpColor::none, unsigned int thickness=1) const
 
bool getPose (size_t tagIndex, double tagSize, const vpCameraParameters &cam, vpHomogeneousMatrix &cMo, vpHomogeneousMatrix *cMo2=NULL, double *projError=NULL, double *projError2=NULL)
 
vpPoseEstimationMethod getPoseEstimationMethod () const
 
std::vector< std::vector< vpImagePoint > > getTagsCorners () const
 
std::vector< int > getTagsId () const
 
std::vector< std::vector< vpPoint > > getTagsPoints3D (const std::vector< int > &tagsId, const std::map< int, double > &tagsSize) const
 
void setAprilTagDecodeSharpening (double decodeSharpening)
 
void setAprilTagFamily (const vpAprilTagFamily &tagFamily)
 
void setAprilTagNbThreads (int nThreads)
 
void setAprilTagPoseEstimationMethod (const vpPoseEstimationMethod &poseEstimationMethod)
 
void setAprilTagQuadDecimate (float quadDecimate)
 
void setAprilTagQuadSigma (float quadSigma)
 
void setAprilTagRefineDecode (bool refineDecode)
 
void setAprilTagRefineEdges (bool refineEdges)
 
void setAprilTagRefinePose (bool refinePose)
 
void setDisplayTag (bool display, const vpColor &color=vpColor::none, unsigned int thickness=2)
 
void setZAlignedWithCameraAxis (bool zAlignedWithCameraFrame)
 
Inherited functionalities from vpDetectorBase
vpRect getBBox (size_t i) const
 
vpImagePoint getCog (size_t i) const
 
std::vector< std::string > & getMessage ()
 
std::string & getMessage (size_t i)
 
size_t getNbObjects () const
 
std::vector< std::vector< vpImagePoint > > & getPolygon ()
 
std::vector< vpImagePoint > & getPolygon (size_t i)
 
void setTimeout (unsigned long timeout_ms)
 

Protected Attributes

bool m_displayTag
 
vpColor m_displayTagColor
 
unsigned int m_displayTagThickness
 
vpPoseEstimationMethod m_poseEstimationMethod
 
vpAprilTagFamily m_tagFamily
 
std::vector< std::vector< vpImagePoint > > m_polygon
 
std::vector< std::string > m_message
 
size_t m_nb_objects
 
unsigned long m_timeout_ms
 

Friends

void swap (vpDetectorAprilTag &o1, vpDetectorAprilTag &o2)
 

Detailed Description

Base class for AprilTag detector. This class is a wrapper over AprilTag. There is no need to download and install AprilTag from source code or existing pre-built packages since the source code is embedded in ViSP. Reference papers are AprilTag: A robust and flexible visual fiducial system ([37]), AprilTag 2: Efficient and robust fiducial detection ([48]) and Flexible Layouts for Fiducial Tags (Under Review) ([24]).

The detect() function allows to detect multiple tags in an image. Once detected, for each tag it is possible to retrieve the location of the corners using getPolygon(), the encoded message using getMessage(), the bounding box using getBBox() and the center of gravity using getCog().

If camera parameters and the size of the tag are provided, you can also estimate the 3D pose of the tag in terms of position and orientation wrt the camera considering 2 cases:

  • 1. If all the tags have the same size use detect(const vpImage<unsigned char> &, const double, const vpCameraParameters &, std::vector<vpHomogeneousMatrix> &)
  • 2. If tag sizes differ, use rather getPose()

The following sample code shows how to use this class to detect the location of 36h11 AprilTag patterns in an image.

#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/io/vpImageIo.h>
int main()
{
#ifdef VISP_HAVE_APRILTAG
vpImageIo::read(I, "image-tag36h11.pgm");
bool status = detector.detect(I);
if (status) {
for(size_t i=0; i < detector.getNbObjects(); i++) {
std::cout << "Tag code " << i << ":" << std::endl;
std::vector<vpImagePoint> p = detector.getPolygon(i);
for(size_t j=0; j < p.size(); j++)
std::cout << " Point " << j << ": " << p[j] << std::endl;
std::cout << " Message: \"" << detector.getMessage(i) << "\"" << std::endl;
}
}
#endif
}
@ TAG_36h11
AprilTag 36h11 pattern (recommended)
static void read(vpImage< unsigned char > &I, const std::string &filename, int backend=IO_DEFAULT_BACKEND)
Definition: vpImageIo.cpp:143

The previous example may produce results like:

Tag code 0:
Point 0: 124.008, 442.226
Point 1: 194.614, 441.237
Point 2: 184.833, 540.386
Point 3: 111.948, 533.634
Message: "36h11 id: 0"
Tag code 1:
Point 0: 245.327, 438.801
Point 1: 338.116, 437.221
Point 2: 339.341, 553.539
Point 3: 238.954, 543.855
Message: "36h11 id: 1"

This other example shows how to estimate the 3D pose of 36h11 AprilTag patterns considering that all the tags have the same size (in our example 0.053 m).

#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/io/vpImageIo.h>
int main()
{
#ifdef VISP_HAVE_APRILTAG
vpImageIo::read(I, "image-tag36h11.pgm");
std::vector<vpHomogeneousMatrix> cMo;
cam.initPersProjWithoutDistortion(615.1674805, 615.1675415, 312.1889954, 243.4373779);
double tagSize = 0.053;
bool status = detector.detect(I, tagSize, cam, cMo);
if (status) {
for(size_t i=0; i < detector.getNbObjects(); i++) {
std::cout << "Tag number " << i << ":" << std::endl;
std::cout << " Message: \"" << detector.getMessage(i) << "\"" << std::endl;
std::cout << " Pose: " << vpPoseVector(cMo[i]).t() << std::endl;
std::size_t tag_id_pos = detector.getMessage(i).find("id: ");
if (tag_id_pos != std::string::npos) {
std::string tag_id = detector.getMessage(i).substr(tag_id_pos + 4);
std::cout << " Tag Id: " << tag_id << std::endl;
}
}
}
#endif
}
Generic class defining intrinsic camera parameters.
void initPersProjWithoutDistortion(double px, double py, double u0, double v0)
Implementation of a pose vector and operations on poses.
Definition: vpPoseVector.h:192
vpRowVector t() const

The previous example may produce results like:

Tag number 0:
Message: "36h11 id: 0"
Pose: 0.1015061088 -0.05239057228 0.3549037285 1.991474322 2.04143538 -0.9412360063
Tag Id: 0
Tag number 1:
Message: "36h11 id: 1"
Pose: 0.08951250829 0.02243780207 0.306540622 1.998073197 2.061488008 -0.8699567948
Tag Id: 1

In this other example we estimate the 3D pose of 36h11 AprilTag patterns considering that tag 36h11 with id 0 (in that case the tag message is "36h11 id: 0") has a size of 0.040 m, while all the others have a size of 0.053m.

#include <visp3/detection/vpDetectorAprilTag.h>
#include <visp3/io/vpImageIo.h>
int main()
{
#ifdef VISP_HAVE_APRILTAG
vpImageIo::read(I, "image-tag36h11.pgm");
cam.initPersProjWithoutDistortion(615.1674805, 615.1675415, 312.1889954, 243.4373779);
double tagSize_id_0 = 0.04;
double tagSize_id_others = 0.053;
bool status = detector.detect(I);
if (status) {
for(size_t i=0; i < detector.getNbObjects(); i++) {
std::cout << "Tag code " << i << ":" << std::endl;
std::cout << " Message: \"" << detector.getMessage(i) << "\"" << std::endl;
if (detector.getMessage(i) == std::string("36h11 id: 0")) {
if (! detector.getPose(i, tagSize_id_0, cam, cMo)) {
std::cout << "Unable to get tag index " << i << " pose!" << std::endl;
}
}
else {
if (! detector.getPose(i, tagSize_id_others, cam, cMo)) {
std::cout << "Unable to get tag index " << i << " pose!" << std::endl;
}
}
std::cout << " Pose: " << vpPoseVector(cMo).t() << std::endl;
}
}
#endif
}
Implementation of an homogeneous matrix and operations on such kind of matrices.

With respect to the previous example, this example may now produce a different pose for tag with id 0:

Tag code 0:
Message: "36h11 id: 0"
Pose: 0.07660838403 -0.03954005455 0.2678518706 1.991474322 2.04143538 -0.9412360063
Tag code 1:
Message: "36h11 id: 1"
Pose: 0.08951250829 0.02243780207 0.306540622 1.998073197 2.061488008 -0.8699567948

Other examples are also provided in tutorial-apriltag-detector.cpp and tutorial-apriltag-detector-live.cpp

Examples
mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, servoAfma6AprilTagIBVS.cpp, servoAfma6AprilTagPBVS.cpp, servoBebop2.cpp, servoFlirPtuIBVS.cpp, servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, servoPixhawkDroneIBVS.cpp, servoUniversalRobotsIBVS.cpp, servoUniversalRobotsPBVS.cpp, testAprilTag.cpp, tutorial-apriltag-detector-live-T265-realsense.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, tutorial-apriltag-detector-live-rgbd-structure-core.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-flir-ptu-ibvs.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, and tutorial-mb-generic-tracker-apriltag-webcam.cpp.

Definition at line 216 of file vpDetectorAprilTag.h.

Member Enumeration Documentation

◆ vpAprilTagFamily

Enumerator
TAG_36h11 

AprilTag 36h11 pattern (recommended)

TAG_36h10 

DEPRECATED.

TAG_36ARTOOLKIT 

DEPRECATED AND WILL NOT DETECT ARTOOLKIT TAGS.

TAG_25h9 

AprilTag 25h9 pattern.

TAG_25h7 

DEPRECATED AND POOR DETECTION PERFORMANCE.

TAG_16h5 

AprilTag 16h5 pattern.

TAG_CIRCLE21h7 

AprilTag Circle21h7 pattern.

TAG_CIRCLE49h12 

AprilTag Circle49h12 pattern.

TAG_CUSTOM48h12 

AprilTag Custom48h12 pattern.

TAG_STANDARD41h12 

AprilTag Standard41h12 pattern.

TAG_STANDARD52h13 

AprilTag Standard52h13 pattern.

Examples
mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, tutorial-apriltag-detector-live-T265-realsense.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, tutorial-apriltag-detector-live-rgbd-structure-core.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, and tutorial-mb-generic-tracker-apriltag-webcam.cpp.

Definition at line 219 of file vpDetectorAprilTag.h.

◆ vpPoseEstimationMethod

Enumerator
HOMOGRAPHY 

Pose from homography

HOMOGRAPHY_VIRTUAL_VS 

Non linear virtual visual servoing approach initialized by the homography approach

DEMENTHON_VIRTUAL_VS 

Non linear virtual visual servoing approach initialized by the Dementhon approach

LAGRANGE_VIRTUAL_VS 

Non linear virtual visual servoing approach initialized by the Lagrange approach

BEST_RESIDUAL_VIRTUAL_VS 

Non linear virtual visual servoing approach initialized by the approach that gives the lowest residual

HOMOGRAPHY_ORTHOGONAL_ITERATION 

Pose from homography followed by a refinement by Orthogonal Iteration

Examples
tutorial-apriltag-detector-live-T265-realsense.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, tutorial-apriltag-detector-live-rgbd-structure-core.cpp, tutorial-apriltag-detector-live.cpp, and tutorial-apriltag-detector.cpp.

Definition at line 233 of file vpDetectorAprilTag.h.

Constructor & Destructor Documentation

◆ vpDetectorAprilTag() [1/2]

vpDetectorAprilTag::vpDetectorAprilTag ( const vpAprilTagFamily tagFamily = TAG_36h11,
const vpPoseEstimationMethod poseEstimationMethod = HOMOGRAPHY_VIRTUAL_VS 
)

Definition at line 813 of file vpDetectorAprilTag.cpp.

◆ vpDetectorAprilTag() [2/2]

vpDetectorAprilTag::vpDetectorAprilTag ( const vpDetectorAprilTag o)

Definition at line 821 of file vpDetectorAprilTag.cpp.

◆ ~vpDetectorAprilTag()

vpDetectorAprilTag::~vpDetectorAprilTag ( )
virtual

Definition at line 834 of file vpDetectorAprilTag.cpp.

Member Function Documentation

◆ detect() [1/2]

◆ detect() [2/2]

bool vpDetectorAprilTag::detect ( const vpImage< unsigned char > &  I,
double  tagSize,
const vpCameraParameters cam,
std::vector< vpHomogeneousMatrix > &  cMo_vec,
std::vector< vpHomogeneousMatrix > *  cMo_vec2 = NULL,
std::vector< double > *  projErrors = NULL,
std::vector< double > *  projErrors2 = NULL 
)

Detect AprilTag tags in the image and compute the corresponding tag poses considering that all the tags have the same size.

If tags with different sizes have to be considered, you may use getPose().

Parameters
[in]I: Input image.
[in]tagSize: Tag size in meter corresponding to the external width of the pattern.
[in]cam: Camera intrinsic parameters.
[out]cMo_vec: List of tag poses.
[out]cMo_vec2: Optional second list of tag poses, since there are 2 solutions for planar pose estimation.
[out]projErrors: Optional (sum of squared) projection errors in the normalized camera frame.
[out]projErrors2: Optional (sum of squared) projection errors for the 2nd solution in the normalized camera frame.
Returns
true if at least one tag is detected.
See also
getPose()

Definition at line 875 of file vpDetectorAprilTag.cpp.

References m_displayTag, m_displayTagColor, m_displayTagThickness, vpDetectorBase::m_message, vpDetectorBase::m_nb_objects, and vpDetectorBase::m_polygon.

◆ displayFrames() [1/2]

void vpDetectorAprilTag::displayFrames ( const vpImage< unsigned char > &  I,
const std::vector< vpHomogeneousMatrix > &  cMo_vec,
const vpCameraParameters cam,
double  size,
const vpColor color,
unsigned int  thickness = 1 
) const

Display the tag frames on a grayscale image.

Parameters
[in]I: The image.
[in]cMo_vec: The vector of computed tag poses.
[in]cam: Camera intrinsic parameters.
[out]size: Size of the frame.
[out]color: The desired color, if none the X-axis is red, the Y-axis green and the Z-axis blue.
[out]thickness: The thickness of the lines.
Examples
tutorial-apriltag-detector.cpp.

Definition at line 904 of file vpDetectorAprilTag.cpp.

◆ displayFrames() [2/2]

void vpDetectorAprilTag::displayFrames ( const vpImage< vpRGBa > &  I,
const std::vector< vpHomogeneousMatrix > &  cMo_vec,
const vpCameraParameters cam,
double  size,
const vpColor color,
unsigned int  thickness = 1 
) const

Display the tag frames on a vpRGBa image.

Parameters
[in]I: The image.
[in]cMo_vec: The vector of computed tag poses.
[in]cam: Camera intrinsic parameters.
[out]size: Size of the frame.
[out]color: The desired color, if none the X-axis is red, the Y-axis green and the Z-axis blue.
[out]thickness: The thickness of the lines.

Definition at line 920 of file vpDetectorAprilTag.cpp.

◆ displayTags() [1/2]

void vpDetectorAprilTag::displayTags ( const vpImage< unsigned char > &  I,
const std::vector< std::vector< vpImagePoint > > &  tagsCorners,
const vpColor color = vpColor::none,
unsigned int  thickness = 1 
) const

Display the tag contours on a grayscale image.

Parameters
[in]I: The image.
[in]tagsCorners: The vector of tag contours.
[out]color: The desired color, if none RGBY colors are used.
[out]thickness: The thickness of the lines.
Examples
tutorial-apriltag-detector.cpp.

Definition at line 934 of file vpDetectorAprilTag.cpp.

◆ displayTags() [2/2]

void vpDetectorAprilTag::displayTags ( const vpImage< vpRGBa > &  I,
const std::vector< std::vector< vpImagePoint > > &  tagsCorners,
const vpColor color = vpColor::none,
unsigned int  thickness = 1 
) const

Display the tag contours on a vpRGBa image.

Parameters
[in]I: The image.
[in]tagsCorners: The vector of tag contours.
[out]color: The desired color, if none RGBY colors are used.
[out]thickness: The thickness of the lines.

Definition at line 948 of file vpDetectorAprilTag.cpp.

◆ getBBox()

◆ getCog()

vpImagePoint vpDetectorBase::getCog ( size_t  i) const
inherited

Return the center of gravity location of the ith object.

Examples
mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, and tutorial-flir-ptu-ibvs.cpp.

Definition at line 76 of file vpDetectorBase.cpp.

References vpDetectorBase::m_polygon.

◆ getMessage() [1/2]

std::vector<std::string>& vpDetectorBase::getMessage ( )
inlineinherited

◆ getMessage() [2/2]

std::string & vpDetectorBase::getMessage ( size_t  i)
inherited

Returns the contained message of the ith object if there is one.

Definition at line 64 of file vpDetectorBase.cpp.

References vpException::badValue, vpDetectorBase::m_message, and vpDetectorBase::m_polygon.

◆ getNbObjects()

◆ getPolygon() [1/2]

◆ getPolygon() [2/2]

std::vector< vpImagePoint > & vpDetectorBase::getPolygon ( size_t  i)
inherited

Returns ith object container box as a vector of points.

Definition at line 52 of file vpDetectorBase.cpp.

References vpException::badValue, and vpDetectorBase::m_polygon.

◆ getPose()

bool vpDetectorAprilTag::getPose ( size_t  tagIndex,
double  tagSize,
const vpCameraParameters cam,
vpHomogeneousMatrix cMo,
vpHomogeneousMatrix cMo2 = NULL,
double *  projError = NULL,
double *  projError2 = NULL 
)

Get the pose of a tag depending on its size and camera parameters. This function is useful to get the pose of tags with different sizes, while detect(const vpImage<unsigned char> &, const double, const vpCameraParameters &, std::vector<vpHomogeneousMatrix> &) considers that all the tags have the same size.

Parameters
[in]tagIndex: Index of the tag. Value should be in range [0, nb tags-1] with nb_tags = getNbObjects(). Note that this index doesn't correspond to the tag id.
[in]tagSize: Tag size in meter corresponding to the external width of the pattern.
[in]cam: Camera intrinsic parameters.
[out]cMo: Pose of the tag.
[out]cMo2: Optional second pose of the tag.
[out]projError: Optional (sum of squared) projection errors in the normalized camera frame.
[out]projError2: Optional (sum of squared) projection errors for the 2nd solution in the normalized camera frame.
Returns
true if success, false otherwise.

The following code shows how to use this function:

detector.detect(I);
for (size_t i = 0; i < detector.getNbObjects(); i++) {
double tagSize = 0.1;
detector.getPose(i, tagSize, cam, cMo);
}
See also
detect(const vpImage<unsigned char> &, double, const vpCameraParameters &, std::vector<vpHomogeneousMatrix> *, std::vector<vpHomogeneousMatrix> *, std::vector<double> *, std::vector<double> *)
Examples
testAprilTag.cpp.

Definition at line 985 of file vpDetectorAprilTag.cpp.

◆ getPoseEstimationMethod()

vpPoseEstimationMethod vpDetectorAprilTag::getPoseEstimationMethod ( ) const
inline

Return the pose estimation method.

Definition at line 274 of file vpDetectorAprilTag.h.

◆ getTagsCorners()

std::vector< std::vector< vpImagePoint > > vpDetectorAprilTag::getTagsCorners ( ) const

Return the corners coordinates for the detected tags.

See also
getTagsId(), getTagsPoints3D()
Examples
testAprilTag.cpp, tutorial-apriltag-detector-live-T265-realsense.cpp, and tutorial-apriltag-detector.cpp.

Definition at line 1055 of file vpDetectorAprilTag.cpp.

References vpDetectorBase::m_polygon.

◆ getTagsId()

std::vector< int > vpDetectorAprilTag::getTagsId ( ) const

◆ getTagsPoints3D()

std::vector< std::vector< vpPoint > > vpDetectorAprilTag::getTagsPoints3D ( const std::vector< int > &  tagsId,
const std::map< int, double > &  tagsSize 
) const

Return a vector that contains for each tag id the corresponding tag 3D corners coordinates in the tag frame.

Parameters
tagsId: A vector containing the id of each tag that is detected. It's size corresponds to the number of tags that are detected. This vector is returned by getTagsId().
tagsSize: a map that contains as first element a tag id and as second elements its 3D size in meter. When first element of this map is -1, the second element corresponds to the default tag size.
std::map<int, double> tagsSize;
tagsSize[-1] = 0.05; // Default tag size in meter, used when detected tag id is not in this map
tagsSize[10] = 0.1; // All tags with id 10 are 0.1 meter large
tagsSize[20] = 0.2; // All tags with id 20 are 0.2 meter large
See also
getTagsCorners(), getTagsId()
Examples
testAprilTag.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, and tutorial-apriltag-detector-live-rgbd-structure-core.cpp.

Definition at line 1009 of file vpDetectorAprilTag.cpp.

References vpException::fatalError.

◆ operator=()

vpDetectorAprilTag & vpDetectorAprilTag::operator= ( vpDetectorAprilTag  o)

Definition at line 828 of file vpDetectorAprilTag.cpp.

References swap.

◆ setAprilTagDecodeSharpening()

void vpDetectorAprilTag::setAprilTagDecodeSharpening ( double  decodeSharpening)

Definition at line 1064 of file vpDetectorAprilTag.cpp.

◆ setAprilTagFamily()

void vpDetectorAprilTag::setAprilTagFamily ( const vpAprilTagFamily tagFamily)

Definition at line 1069 of file vpDetectorAprilTag.cpp.

References m_poseEstimationMethod.

◆ setAprilTagNbThreads()

◆ setAprilTagPoseEstimationMethod()

void vpDetectorAprilTag::setAprilTagPoseEstimationMethod ( const vpPoseEstimationMethod poseEstimationMethod)

◆ setAprilTagQuadDecimate()

void vpDetectorAprilTag::setAprilTagQuadDecimate ( float  quadDecimate)

From the AprilTag code:

detection of quads can be done on a lower-resolution image, improving speed at a cost of pose accuracy and a slight decrease in detection rate. Decoding the binary payload is still done at full resolution.

Default is 1.0, increase this value to reduce the computation time.

Parameters
quadDecimate: Value for quad_decimate.
Examples
mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, testAprilTag.cpp, tutorial-apriltag-detector-live-T265-realsense.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, tutorial-apriltag-detector-live-rgbd-structure-core.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-flir-ptu-ibvs.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, and tutorial-mb-generic-tracker-apriltag-webcam.cpp.

Definition at line 1129 of file vpDetectorAprilTag.cpp.

◆ setAprilTagQuadSigma()

void vpDetectorAprilTag::setAprilTagQuadSigma ( float  quadSigma)

From the AprilTag code:

What Gaussian blur should be applied to the segmented image (used for quad detection?) Parameter is the standard deviation in pixels. Very noisy images benefit from non-zero values (e.g. 0.8).

Default is 0.0.

Parameters
quadSigma: Value for quad_sigma.

Definition at line 1143 of file vpDetectorAprilTag.cpp.

◆ setAprilTagRefineDecode()

vp_deprecated void vpDetectorAprilTag::setAprilTagRefineDecode ( bool  refineDecode)

Deprecated parameter from AprilTag 2 version.

Definition at line 1149 of file vpDetectorAprilTag.cpp.

◆ setAprilTagRefineEdges()

void vpDetectorAprilTag::setAprilTagRefineEdges ( bool  refineEdges)

From the AprilTag code:

When non-zero, the edges of the each quad are adjusted to "snap to" strong gradients nearby. This is useful when decimation is employed, as it can increase the quality of the initial quad estimate substantially. Generally recommended to be on (1). Very computationally inexpensive. Option is ignored if quad_decimate = 1.

Default is 1.

Parameters
refineEdges: If true, set refine_edges to 1.

Definition at line 1169 of file vpDetectorAprilTag.cpp.

◆ setAprilTagRefinePose()

vp_deprecated void vpDetectorAprilTag::setAprilTagRefinePose ( bool  refinePose)

Deprecated parameter from AprilTag 2 version.

Definition at line 1175 of file vpDetectorAprilTag.cpp.

◆ setDisplayTag()

void vpDetectorAprilTag::setDisplayTag ( bool  display,
const vpColor color = vpColor::none,
unsigned int  thickness = 2 
)
inline

◆ setTimeout()

void vpDetectorBase::setTimeout ( unsigned long  timeout_ms)
inlineinherited

Set detector timeout in milli-seconds. When set to 0, there is no timeout.

Definition at line 126 of file vpDetectorBase.h.

Referenced by vpDetectorDataMatrixCode::vpDetectorDataMatrixCode().

◆ setZAlignedWithCameraAxis()

void vpDetectorAprilTag::setZAlignedWithCameraAxis ( bool  zAlignedWithCameraFrame)

Modify the resulting tag pose returned by getPose() in order to get a pose where z-axis is aligned when the camera plane is parallel to the tag.

Parameters
zAlignedWithCameraFrame: Flag to get a pose where z-axis is aligned with the camera frame.
Examples
tutorial-apriltag-detector-live-T265-realsense.cpp, tutorial-apriltag-detector-live-rgbd-realsense.cpp, tutorial-apriltag-detector-live-rgbd-structure-core.cpp, tutorial-apriltag-detector-live.cpp, and tutorial-apriltag-detector.cpp.

Definition at line 1190 of file vpDetectorAprilTag.cpp.

Friends And Related Function Documentation

◆ swap

void swap ( vpDetectorAprilTag o1,
vpDetectorAprilTag o2 
)
friend

Definition at line 1178 of file vpDetectorAprilTag.cpp.

Referenced by operator=().

Member Data Documentation

◆ m_displayTag

bool vpDetectorAprilTag::m_displayTag
protected

Definition at line 305 of file vpDetectorAprilTag.h.

Referenced by detect().

◆ m_displayTagColor

vpColor vpDetectorAprilTag::m_displayTagColor
protected

Definition at line 306 of file vpDetectorAprilTag.h.

Referenced by detect().

◆ m_displayTagThickness

unsigned int vpDetectorAprilTag::m_displayTagThickness
protected

Definition at line 307 of file vpDetectorAprilTag.h.

Referenced by detect().

◆ m_message

std::vector<std::string> vpDetectorBase::m_message
protectedinherited

Message attached to each object.

Definition at line 65 of file vpDetectorBase.h.

Referenced by vpDetectorFace::detect(), detect(), vpDetectorDataMatrixCode::detect(), vpDetectorQRCode::detect(), and vpDetectorBase::getMessage().

◆ m_nb_objects

size_t vpDetectorBase::m_nb_objects
protectedinherited

Number of detected objects.

Definition at line 66 of file vpDetectorBase.h.

Referenced by vpDetectorFace::detect(), detect(), vpDetectorDataMatrixCode::detect(), and vpDetectorQRCode::detect().

◆ m_polygon

std::vector<std::vector<vpImagePoint> > vpDetectorBase::m_polygon
protectedinherited

◆ m_poseEstimationMethod

vpPoseEstimationMethod vpDetectorAprilTag::m_poseEstimationMethod
protected

Definition at line 308 of file vpDetectorAprilTag.h.

Referenced by setAprilTagFamily(), and setAprilTagPoseEstimationMethod().

◆ m_tagFamily

vpAprilTagFamily vpDetectorAprilTag::m_tagFamily
protected

Definition at line 309 of file vpDetectorAprilTag.h.

◆ m_timeout_ms

unsigned long vpDetectorBase::m_timeout_ms
protectedinherited

Detection timeout.

Definition at line 67 of file vpDetectorBase.h.

Referenced by vpDetectorDataMatrixCode::detect().