#include <vpOpenCVGrabber.h>

Inheritance diagram for vpOpenCVGrabber:

Public Member Functions
	vpOpenCVGrabber ()

	~vpOpenCVGrabber ()

void	open ()

void	open (vpImage< unsigned char > &I)

void	open (vpImage< vpRGBa > &I)

void	acquire (vpImage< unsigned char > &I)

void	acquire (vpImage< vpRGBa > &I)

IplImage *	acquire ()

void	close ()

void	getFramerate (double &framerate)

void	setFramerate (const double framerate)

void	setWidth (const unsigned int width)

void	setHeight (const unsigned int height)

void	setDeviceType (int type)

void	setFlip (bool flipType)

unsigned int	getHeight () const

unsigned int	getWidth () const

Public Attributes
bool	init

Protected Attributes
unsigned int	height

unsigned int	width

Detailed Description

Class for cameras video capture using OpenCV library.

Needs OpenCV available on http://opencv.willowgarage.com/wiki/.

The code below available in tutorial-grabber-opencv.cpp shows how to grab and display images using OpenCV wrappers impremented in ViSP.

#include <visp/vpDisplayOpenCV.h>
#include <visp/vpOpenCVGrabber.h>
int main()
{
#ifdef VISP_HAVE_OPENCV
  try {
    vpImage<unsigned char> I;
    vpOpenCVGrabber g;
    g.open(I);
    std::cout << "Image size: " << I.getWidth() << " " << I.getHeight() << std::endl;
    vpDisplayOpenCV d(I);
    while(1) {
      g.acquire(I);
      vpDisplay::display(I);
      vpDisplay::flush(I);
      if (vpDisplay::getClick(I, false))
        break;
    }
  }
  catch(vpException e) {
    std::cout << "Catch an exception: " << e << std::endl;
  }
#endif
}

Note that it is also possible to grab images using OpenCV library by using directly OpenCV cv::VideoCapture class. The following code corresponding to tutorial-grabber-opencv-bis.cpp shows how to grab images in a cv::Mat structure and then convert OpenCV images in ViSP images.

#include <stdlib.h>
#include <visp/vpDisplayOpenCV.h>
#include <visp/vpImageConvert.h>
// usage: binary <device name>
// device name: 0 is the default to dial with the first camera,
// 1 to dial with a second camera attached to the computer
int main(int argc, char** argv)
{
  int device = 0;
  if (argc > 1)
    device = atoi(argv[1]);
  std::cout << "Use device: " << device << std::endl;
#if defined(VISP_HAVE_OPENCV) && (VISP_HAVE_OPENCV_VERSION >= 0x020100)
  try {
    cv::VideoCapture cap(device); // open the default camera
    if(!cap.isOpened()) { // check if we succeeded
      std::cout << "Failed to open the camera" << std::endl;
      return -1;
    }
    cv::Mat frame;
    cap >> frame; // get a new frame from camera
    std::cout << "Image size: " << frame.rows << " " << frame.cols << std::endl;
    //vpImage<vpRGBa> I; // for color images
    vpImage<unsigned char> I; // for gray images
    vpImageConvert::convert(frame, I);
    vpDisplayOpenCV d(I);
    for(;;) {
      cap >> frame; // get a new frame from camera
      // Convert the image in ViSP format and display it
      vpImageConvert::convert(frame, I);
      vpDisplay::display(I);
      vpDisplay::flush(I);
      if (vpDisplay::getClick(I, false)) // a click to exit
        break;
    }
  }
  catch(vpException e) {
    std::cout << "Catch an exception: " << e << std::endl;
  }
#endif
}

An other example very close to the previous one available in grabOpenCV-2.cpp shows how to grab images in OpenCV IplImage structure and then how to convert OpenCV images in ViSP images.

Examples:: fernClassifier.cpp, grabOpenCV.cpp, HelloWorldOgre.cpp, HelloWorldOgreAdvanced.cpp, planarObjectDetector.cpp, and tutorial-grabber-opencv.cpp.

Definition at line 88 of file vpOpenCVGrabber.h.

Constructor & Destructor Documentation

vpOpenCVGrabber::vpOpenCVGrabber ( )

Basic Constructor.

Definition at line 60 of file vpOpenCVGrabber.cpp.

References vpFrameGrabber::height, vpFrameGrabber::init, and vpFrameGrabber::width.

vpOpenCVGrabber::~vpOpenCVGrabber ( )

Basic destructor that calls the close() method.

See also: close()

Definition at line 76 of file vpOpenCVGrabber.cpp.

References close().

Member Function Documentation

void vpOpenCVGrabber::acquire ( vpImage< unsigned char > & I )

virtual

Grab a gray level image.

Parameters

I	: Acquired gray level image.

Exceptions

vpFrameGrabberException::initializationError If the initialization of the grabber was not done previously.

Implements vpFrameGrabber.

Examples:: fernClassifier.cpp, grabOpenCV.cpp, HelloWorldOgre.cpp, HelloWorldOgreAdvanced.cpp, planarObjectDetector.cpp, and tutorial-grabber-opencv.cpp.

Definition at line 140 of file vpOpenCVGrabber.cpp.

References close(), vpImageConvert::convert(), vpFrameGrabber::init, and vpFrameGrabberException::initializationError.

void vpOpenCVGrabber::acquire ( vpImage< vpRGBa > & I )

virtual

Grab a color image.

Parameters

I	: Acquired color image.

Exceptions

vpFrameGrabberException::initializationError If the initialization of the grabber was not done previously.

Implements vpFrameGrabber.

Definition at line 164 of file vpOpenCVGrabber.cpp.

References close(), vpImageConvert::convert(), vpFrameGrabber::init, and vpFrameGrabberException::initializationError.

IplImage * vpOpenCVGrabber::acquire ( )

Grab an image direclty in the OpenCV format.

Returns: Pointer to the image (must not be freed).

Exceptions

vpFrameGrabberException::initializationError If the initialization of the grabber was not done previously.

Definition at line 188 of file vpOpenCVGrabber.cpp.

References close(), vpFrameGrabber::init, and vpFrameGrabberException::initializationError.

void vpOpenCVGrabber::close ( )

virtual

Stop the acquisition of images and free the camera.

Implements vpFrameGrabber.

Examples:: HelloWorldOgre.cpp, and HelloWorldOgreAdvanced.cpp.

Definition at line 207 of file vpOpenCVGrabber.cpp.

References vpFrameGrabber::init.

Referenced by acquire(), open(), setHeight(), setWidth(), and ~vpOpenCVGrabber().

void vpOpenCVGrabber::getFramerate ( double & framerate )

Gets the capture frame rate.

Parameters

framerate : The value of the framerate is returned here.

Definition at line 221 of file vpOpenCVGrabber.cpp.

unsigned int vpFrameGrabber::getHeight ( ) const

inlineinherited

Return the number of rows in the image.

Examples:: AROgre.cpp, AROgreBasic.cpp, HelloWorldOgre.cpp, and HelloWorldOgreAdvanced.cpp.

Definition at line 119 of file vpFrameGrabber.h.

unsigned int vpFrameGrabber::getWidth ( ) const

inlineinherited

Return the number of columns in the image.

Examples:: AROgre.cpp, AROgreBasic.cpp, HelloWorldOgre.cpp, and HelloWorldOgreAdvanced.cpp.

Definition at line 121 of file vpFrameGrabber.h.

void vpOpenCVGrabber::open ( )

Generic initialization of the grabber.

Examples:: fernClassifier.cpp, grabOpenCV.cpp, HelloWorldOgre.cpp, HelloWorldOgreAdvanced.cpp, planarObjectDetector.cpp, and tutorial-grabber-opencv.cpp.

Definition at line 85 of file vpOpenCVGrabber.cpp.

References close(), vpFrameGrabber::init, and vpFrameGrabberException::initializationError.

Referenced by open().

void vpOpenCVGrabber::open ( vpImage< unsigned char > & I )

virtual

Initialization of the grabber. Call the generic initialization method.

Parameters

I	: Gray level image. This parameter is not used.

See also: open()

Implements vpFrameGrabber.

Definition at line 112 of file vpOpenCVGrabber.cpp.

References open().

void vpOpenCVGrabber::open ( vpImage< vpRGBa > & I )

virtual

Initialization of the grabber. Call the generic initialization method.

Parameters

I	: Color image. This parameter is not used.

See also: open()

Implements vpFrameGrabber.

Definition at line 126 of file vpOpenCVGrabber.cpp.

References open().

void vpOpenCVGrabber::setDeviceType ( int type )

Set the expected type of device.

Parameters

type	: expected type of device CV_CAP_ANY CV_CAP_MIL CV_CAP_VFW CV_CAP_V4L CV_CAP_V4L2 CV_CAP_FIREWIRE CV_CAP_IEEE1394 CV_CAP_DC1394 CV_CAP_CMU_1394

Examples:: grabOpenCV.cpp.

Definition at line 299 of file vpOpenCVGrabber.cpp.

References vpTRACE.

void vpOpenCVGrabber::setFlip ( bool flipType )

Set the boolean variable flip to the expected value.

Parameters

flipType : Expected value of the variable flip. True means that the image is flipped during each image acquisition.

Warning: This function is only useful under Windows.

Note: The aim of this function is to fix a problem which appears under Windows. Indeed with several cameras the aquired images are flipped.

Definition at line 319 of file vpOpenCVGrabber.cpp.

void vpOpenCVGrabber::setFramerate ( const double framerate )

Sets the capture frame rate

Parameters

framerate : The requested value of the capture framerate.

Definition at line 233 of file vpOpenCVGrabber.cpp.

void vpOpenCVGrabber::setHeight ( const unsigned int h )

Sets the captured image height.

Warning: This function must be called after open() method.

Parameters

h	: The requested value of the captured image height.

Exceptions

vpFrameGrabberException::initializationError If no camera was found.

Definition at line 272 of file vpOpenCVGrabber.cpp.

References close(), vpFrameGrabber::height, vpFrameGrabberException::initializationError, and vpERROR_TRACE.

void vpOpenCVGrabber::setWidth ( const unsigned int w )

Sets the captured image width.

Warning: This function must be called after open() method.

Parameters

w	: The requested value of the captured image width.

Exceptions

vpFrameGrabberException::initializationError If no camera was found.

Definition at line 249 of file vpOpenCVGrabber.cpp.

References close(), vpFrameGrabberException::initializationError, vpERROR_TRACE, and vpFrameGrabber::width.

Member Data Documentation

unsigned int vpFrameGrabber::height

protectedinherited

bool vpFrameGrabber::init

inherited

Set to true if the frame grabber has been initialized.

Definition at line 111 of file vpFrameGrabber.h.

Referenced by acquire(), vpV4l2Grabber::acquire(), close(), vp1394CMUGrabber::close(), vp1394TwoGrabber::close(), open(), vpDiskGrabber::open(), vpV4l2Grabber::open(), vp1394TwoGrabber::resetBus(), vp1394CMUGrabber::vp1394CMUGrabber(), vp1394TwoGrabber::vp1394TwoGrabber(), vpDiskGrabber::vpDiskGrabber(), vpOpenCVGrabber(), and vpV4l2Grabber::vpV4l2Grabber().

unsigned int vpFrameGrabber::width

protectedinherited

Public Member Functions

Public Attributes

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation