Marker Class Reference

Basic 2D Marker functionality. More...

#include <Marker.h>

Inheritance diagram for Marker:

Public Member Functions
void	CompareCorners (std::vector< Point< cv::Point2d >> &_marker_corners_img, int *orientation, double *error)
	Compares the marker corners with the previous match. More...
void	CompareContent (std::vector< PointDouble > &_marker_corners_img, cv::Mat &gray, Camera *cam, int *orientation) const
	Compares the marker corners with the previous match.
virtual bool	UpdateContent (std::vector< Point< cv::Point2d >> &_marker_corners_img, cv::Mat &gray, Camera *cam, int frame_no=0)
	Updates the marker_content from the image using Homography.
void	UpdatePose (std::vector< Point< cv::Point2d >> &_marker_corners_img, Camera *cam, int orientation, int frame_no=0, bool update_pose=true)
	Updates the markers pose estimation.
virtual bool	DecodeContent (int *orientation)
	Decodes the marker content. Please call UpdateContent before this. This virtual method is meant to be implemented by heirs.
cv::Mat	GetContent () const
	Returns the content as a matrix.
void	SaveMarkerImage (const char *filename, int save_res=0) const
	Saves the marker as an image.
void	ScaleMarkerToImage (cv::Mat &image) const
	Draw the marker filling the ROI in the given image.
void	Visualize (cv::Mat &image, Camera *cam, const cv::Scalar color=CV_RGB(255, 0, 0)) const
	Visualize the marker.
void	SetMarkerSize (double _edge_length=0, int _res=0, double _margin=0)
	Method for resizing the marker dimensions
double	GetMarkerEdgeLength () const
	Get edge length (to support different size markers.
	~Marker ()
	Destructor
	Marker (double _edge_length=0, int _res=0, double _margin=0)
	Default constructor. More...
	Marker (const Marker &m)
	Copy constructor
virtual unsigned long	GetId () const
	Get id for this marker This is used e.g. in MarkerDetector to associate a marker id with an appropriate edge length. This method should be overwritten to return a suitable identification number for each marker type.
virtual void	SetId (unsigned long _id)
int	GetRes () const
double	GetMargin () const
double	GetError (int errors=(MARGIN_ERROR|DECODE_ERROR)) const
	Get marker detection error estimate. More...
void	SetError (int error_type, double value)
	Set the marker error estimate.

Public Attributes
Pose	pose
	The current marker Pose.
std::vector< PointDouble >	marker_points
	Marker color points in marker coordinates.
std::vector< PointDouble >	marker_corners
	Marker corners in marker coordinates.
std::vector< PointDouble >	marker_corners_img
	Marker corners in image coordinates.
std::vector< PointDouble >	marker_margin_w
	Samples to be used in figuring out min/max for thresholding.
std::vector< PointDouble >	marker_margin_b
	Samples to be used in figuring out min/max for thresholding.

Static Public Attributes
static const int	MARGIN_ERROR = 1
static const int	DECODE_ERROR = 2
static const int	TRACK_ERROR = 4

Protected Member Functions
void	VisualizeMarkerPose (cv::Mat &image, Camera *cam, double visualize2d_points[12][2], const cv::Scalar color=CV_RGB(255, 0, 0)) const
virtual void	VisualizeMarkerContent (cv::Mat &image, Camera *cam, double datatext_point[2], double content_point[2]) const
virtual void	VisualizeMarkerError (cv::Mat &image, Camera *cam, double errortext_point[2]) const
bool	UpdateContentBasic (std::vector< PointDouble > &_marker_corners_img, cv::Mat &gray, Camera *cam, int frame_no=0)

Protected Attributes
double	margin_error
double	decode_error
double	track_error
double	edge_length
int	res
double	margin
cv::Mat	marker_content

Detailed Description

Basic 2D Marker functionality.

This class contains the basic Marker functionality for planar markers.

Definition at line 52 of file Marker.h.

Constructor & Destructor Documentation

Marker()

Marker	(	double	_edge_length = 0,
		int	_res = 0,
		double	_margin = 0
	)

Default constructor.

Parameters

_edge_length	Length of the marker's edge in whatever units you are using (e.g. cm)
_res	The marker content resolution in pixels (this is actually
_margin	The marker margin resolution in pixels (The actual captured marker image has pixel resolution of _margin+_res+_margin)

Member Function Documentation

CompareCorners()

void CompareCorners	(	std::vector< Point< cv::Point2d >> &	_marker_corners_img,
		int *	orientation,
		double *	error
	)

Compares the marker corners with the previous match.

In some cases the tracking of the marker can be accepted solely based on this. Returns the marker orientation and an error value describing the pixel error relative to the marker diameter.

GetError()

double GetError ( int  errors = (MARGIN_ERROR | DECODE_ERROR) ) const

inline

Get marker detection error estimate.

Parameters

errors

Flags indicating what error elements are combined The marker detection error can consist of several elements: MARGIN_ERROR is updated in UpdateContent and it indicates erroneous values inside the marginal area. DECODE_ERROR is updated in DecodeContent and it indicates erroneous values inside the actual marker content area. TRACK_ERROR is updated in MarkerDetector.Detect and it indicates the amount of tracking error returned from CompareCorners

Definition at line 181 of file Marker.h.

GetMargin()

double GetMargin ( ) const

inline

Returns the margin thickness, that is, the number of rows or columns of black squares surrounding the content area.

Definition at line 165 of file Marker.h.

GetRes()

int GetRes ( ) const

inline

Returns the resolution (the number of square rows and columns) of the marker content area. The total number of content squares within the content area is resolution*resolution.

Definition at line 155 of file Marker.h.

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The documentation for this class was generated from the following file:

• Marker.h