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
  vpImage<unsigned char> I;
  vpImageIo::read(I, "bar-code.pgm");

  vpDetectorDataMatrixCode detector;

  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::vpDetectorDataMatrixCode

(

)

Default constructor that does nothing.

Definition at line 52 of file vpDetectorDataMatrixCode.cpp.

~vpDetectorDataMatrixCode()

virtual vpDetectorDataMatrixCode::~vpDetectorDataMatrixCode ( )

inlinevirtual

Definition at line 117 of file vpDetectorDataMatrixCode.h.

References vpDetectorBase::detect().

Member Function Documentation

detect()

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.

getBBox()

vpRect vpDetectorBase::getBBox ( size_t  i ) const

inherited

Return the bounding box of the ith object.

Examples:

testAprilTag.cpp, tutorial-apriltag-detector.cpp, tutorial-barcode-detector-live.cpp, tutorial-barcode-detector.cpp, tutorial-face-detector-live-threaded.cpp, tutorial-face-detector-live.cpp, and tutorial-face-detector.cpp.

Definition at line 87 of file vpDetectorBase.cpp.

References vpDetectorBase::m_polygon.

getCog()

vpImagePoint vpDetectorBase::getCog ( size_t  i ) const

inherited

Return the center of gravity location of the ith object.

Definition at line 74 of file vpDetectorBase.cpp.

References vpDetectorBase::m_polygon.

getMessage() [1/2]

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

inlineinherited

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

Examples:

testAprilTag.cpp, tutorial-apriltag-detector.cpp, tutorial-barcode-detector-live.cpp, tutorial-barcode-detector.cpp, tutorial-face-detector-live.cpp, and tutorial-face-detector.cpp.

Definition at line 107 of file vpDetectorBase.h.

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 62 of file vpDetectorBase.cpp.

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

getNbObjects()

size_t vpDetectorBase::getNbObjects ( ) const

inlineinherited

Return the number of objects that are detected.

Examples:

testAprilTag.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-barcode-detector-live.cpp, tutorial-barcode-detector.cpp, tutorial-face-detector-live.cpp, tutorial-face-detector.cpp, and tutorial-pose-from-qrcode-image.cpp.

Definition at line 117 of file vpDetectorBase.h.

getPolygon() [1/2]

std::vector<std::vector<vpImagePoint> >& vpDetectorBase::getPolygon ( )

inlineinherited

Returns object container box as a vector of points.

Examples:

testAprilTag.cpp, tutorial-apriltag-detector.cpp, tutorial-barcode-detector-live.cpp, tutorial-barcode-detector.cpp, and tutorial-pose-from-qrcode-image.cpp.

Definition at line 122 of file vpDetectorBase.h.

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 50 of file vpDetectorBase.cpp.

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

Member Data Documentation

m_message

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().

m_nb_objects

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().

m_polygon

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

protectedinherited

For each object, defines the polygon that contains the object.

Definition at line 67 of file vpDetectorBase.h.

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