Visual Servoing Platform  version 3.2.0 under development (2018-10-16)
vpDetectorDataMatrixCode Class Reference

#include <visp3/detection/vpDetectorDataMatrixCode.h>

+ Inheritance diagram for vpDetectorDataMatrixCode:

Public Member Functions

 vpDetectorDataMatrixCode ()
 
virtual ~vpDetectorDataMatrixCode ()
 
bool detect (const vpImage< unsigned char > &I)
 
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)
 

Protected Attributes

std::vector< std::vector< vpImagePoint > > m_polygon
 
std::vector< std::string > m_message
 
size_t m_nb_objects
 

Detailed Description

Base class for bar code detector. This class is a wrapper over libdmtx available from http://www.libdmtx.org. Installation instructions are provided here https://visp.inria.fr/3rd_dmtx.

The detect() function allows to detect multiple QR codes in an image. Once detected, for each QR code 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().

The following sample code shows how to use this class to detect QR codes in an image.

#include <visp3/detection/vpDetectorDataMatrixCode.h>
#include <visp3/io/vpImageIo.h>
int main()
{
#ifdef VISP_HAVE_DMTX
vpImageIo::read(I, "bar-code.pgm");
bool status = detector.detect(I);
if (status) {
for(size_t i=0; i < detector.getNbObjects(); i++) {
std::cout << "Bar 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
}

The previous example may produce results like:

Bar code 0:
Point 0: 273.21, 78.9799
Point 1: 390.016, 85.1014
Point 2: 388.024, 199.185
Point 3: 269.23, 192.96
Message: "datamatrix 1"
Bar code 1:
Point 0: 262.23, 396.404
Point 1: 381.041, 402.631
Point 2: 378.92, 524.188
Point 3: 257.916, 519.962
Message: "datamatrix 2"

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

Examples:
tutorial-barcode-detector-live.cpp, and tutorial-barcode-detector.cpp.

Definition at line 113 of file vpDetectorDataMatrixCode.h.

Constructor & Destructor Documentation

vpDetectorDataMatrixCode::vpDetectorDataMatrixCode ( )

Default constructor that does nothing.

Definition at line 52 of file vpDetectorDataMatrixCode.cpp.

virtual vpDetectorDataMatrixCode::~vpDetectorDataMatrixCode ( )
inlinevirtual

Definition at line 117 of file vpDetectorDataMatrixCode.h.

References vpDetectorBase::detect().

Member Function Documentation

bool vpDetectorDataMatrixCode::detect ( const vpImage< unsigned char > &  I)
virtual

Detect datamatrix bar codes in the image. Return true if a bar code is detected, false otherwise.

Parameters
I: Input image.

Implements vpDetectorBase.

Definition at line 60 of file vpDetectorDataMatrixCode.cpp.

References vpImage< Type >::bitmap, vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpDetectorBase::m_message, vpDetectorBase::m_nb_objects, and vpDetectorBase::m_polygon.

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, and mbot-apriltag-ibvs.cpp.

Definition at line 74 of file vpDetectorBase.cpp.

References vpDetectorBase::m_polygon.

std::vector<std::string>& vpDetectorBase::getMessage ( void  )
inlineinherited
std::string & vpDetectorBase::getMessage ( size_t  i)
inherited

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

Definition at line 62 of file vpDetectorBase.cpp.

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

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

Returns ith object container box as a vector of points.

Definition at line 50 of file vpDetectorBase.cpp.

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

Member Data Documentation

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

Message attached to each object.

Definition at line 71 of file vpDetectorBase.h.

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

size_t vpDetectorBase::m_nb_objects
protectedinherited

Number of detected objects.

Definition at line 72 of file vpDetectorBase.h.

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

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