rnr::CameraCv Class Reference

OpenCv implementation of the camera class. The video is streamed via OpenCv calls. More...

#include <CameraCv.h>

Inheritance diagram for rnr::CameraCv:

Public Member Functions
	CameraCv (const std::string &strVideoDevName="/dev/video0", const CamRes &resVideo=CamResQVGA, const CamRes &resImage=CamResVGA)
virtual	~CameraCv ()
	Destructor.
virtual int	startVideo (const CamRes &resVideo=CamResDft)
	Start the camera streaming video. More...
virtual int	stopVideo ()
	Stop the camera from streaming video. More...
virtual int	grabFrame (cv::Mat &frame)
	Grab a image frame from the video stream. More...
virtual int	clickImage (cv::Mat &img, const CamRes &resImage=CamResDft)
	Take a still image. More...
virtual void	autoFocus ()
	Auto-focus camera.
cv::VideoCapture &	getCaptureObj ()
	Get OpenCV captured object. More...
Public Member Functions inherited from rnr::Camera
	Camera (const std::string &strVideoDevName=VideoDevDft, const CamRes &resVideo=CamResQVGA, const CamRes &resImage=CamResVGA)
virtual	~Camera ()
	Destructor. More...
bool	isCameraRunning () const
	Test if the camera is on and running. More...
bool	isTakingAnImage () const
	Test if a still image is currently being taken. More...
bool	isFatal () const
	Test if camera object is in a fatal condition. More...
CamRes	getVideoResolution () const
	Get the current video resolution. More...
CamRes	getImageResolution () const
	Get the current still image resolution. More...

Protected Member Functions
virtual CamRes	setCameraResolution (const CamRes &res)
	Set the camera resolution in either video or still image mode. More...

Protected Attributes
cv::VideoCapture	m_capture
	video capture object
Protected Attributes inherited from rnr::Camera
std::string	m_strVideoDevName
	video device name
int	m_nVideoIndex
	video index
CamRes	m_resCurrent
	current camera resolution
CamRes	m_resVideo
	current video resolution
CamRes	m_resImage
	current still image resolution
bool	m_bCameraRunning
	camera is [not] on and running video
bool	m_bTakingImage
	taking an image is [not] finished
bool	m_bFatal
	camera instance is in a fatal state

Additional Inherited Members
Static Public Member Functions inherited from rnr::Camera
static bool	isEqResolution (const CamRes &res1, const CamRes &res2)
	Check is two camera resolutions are equal. More...
static int	getVideoIndex (const std::string &strVideoDevName)
	Get the video index associated with the device. More...

Detailed Description

OpenCv implementation of the camera class. The video is streamed via OpenCv calls.

Definition at line 83 of file CameraCv.h.

Member Function Documentation

int CameraCv::clickImage ( cv::Mat &  img, const CamRes &  resImage = CamResDft  )

virtual

Take a still image.

Parameters

[in,out]	img	Snap shot image taken.
	resImage	Still image resolution. If equal to CamResDft, then the initial/last image resolution setting is used.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Reimplemented from rnr::Camera.

Definition at line 188 of file CameraCv.cxx.

References rnr::CamResDft, rnr::Camera::grabFrame(), rnr::CamRes::height, rnr::Camera::isCameraRunning(), rnr::Camera::isEqResolution(), rnr::Camera::m_bTakingImage, rnr::Camera::m_resCurrent, rnr::Camera::m_resImage, rnr::Camera::m_resVideo, rnr::Camera::setCameraResolution(), rnr::Camera::startVideo(), rnr::Camera::stopVideo(), and rnr::CamRes::width.

Referenced by rnr::CameraGst::grabFrame().

{
  CamRes  resVideoPrev    = m_resVideo;
  bool    bCamWasRunning  = isCameraRunning();
  CamRes  res             = resImage;
  int     rc;

  m_bTakingImage = true;

  // default is the current image resolution
  if( isEqResolution(res, CamResDft) )
  {
    res = m_resImage;
  }

  //
  // Camera not running - start camera at image resolution.
  //
  if( !isCameraRunning() )
  {
    if( (rc = startVideo(res)) < 0 )
    {
      m_bTakingImage = false;
      return RC_ERROR;
    }
  }

  //
  // Camera already running, but at a different resolution. Set camera at image
  // resolution.
  //
  else if( !isEqResolution(res, m_resCurrent) )
  {
    setCameraResolution(res);
  }

  m_resImage = m_resCurrent;

  //
  // Grab a video frame.
  //
  if( grabFrame(img) < 0 )
  {
    LOGERROR("Cannot grab a snap shot.");
    m_bTakingImage = false;
    return RC_ERROR;
  }

  //
  // Success
  //
  m_resImage.width  = img.cols;
  m_resImage.height = img.rows;

  LOGDIAG3("Took a %dx%d still image.", m_resImage.width, m_resImage.height);

  m_bTakingImage = false;

  m_resVideo = resVideoPrev;

  if( !isEqResolution(m_resVideo, m_resCurrent) )
  {
    startVideo(m_resVideo);
  }

  if( !bCamWasRunning )
  {
    stopVideo();
  }

  return OK;
}

cv::VideoCapture& rnr::CameraCv::getCaptureObj ( )

inline

Get OpenCV captured object.

Returns

Returns CvCapture*.

Definition at line 149 of file CameraCv.h.

References m_capture.

    {
      return m_capture;
    }

int CameraCv::grabFrame ( cv::Mat &  frame )

virtual

Grab a image frame from the video stream.

Parameters

[in,out]

The

image frame matrix. May be resized.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Reimplemented from rnr::Camera.

Definition at line 160 of file CameraCv.cxx.

References rnr::Camera::isCameraRunning().

{
  if( !isCameraRunning() )
  {
    LOGERROR("No video capture object.");
    return RC_ERROR;
  }

  // grab a frame into internal buffer
  else if( !m_capture.grab() )
  {
    LOGERROR("Frame grab() failed.");
    return RC_ERROR;
  }

  // convert grabbed frame to RGB image (not saved)
  else if( !m_capture.retrieve(frame) )
  {
    LOGERROR("Frame retrieve() failed.");
    return RC_ERROR;
  }

  else
  {
    return OK;
  }
}

CamRes CameraCv::setCameraResolution ( const CamRes &  res )

protectedvirtual

Set the camera resolution in either video or still image mode.

Parameters

res	Target camera resolution.

Returns

Actual resolution set.

Reimplemented from rnr::Camera.

Definition at line 265 of file CameraCv.cxx.

References rnr::CamRes::height, rnr::Camera::m_resCurrent, and rnr::CamRes::width.

Referenced by rnr::CameraGst::clickImage(), and rnr::CameraGst::startVideo().

{
  m_capture.set(CV_CAP_PROP_FRAME_WIDTH, res.width);
  m_capture.set(CV_CAP_PROP_FRAME_HEIGHT, res.height);

  m_resCurrent = res;

  return m_resCurrent;
}

int CameraCv::startVideo ( const CamRes &  resVideo = CamResDft )

virtual

Start the camera streaming video.

Parameters

resVideo

Video resolution. If equal to CamResDft, then the initial/last video resolution setting is used.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Reimplemented from rnr::Camera.

Definition at line 89 of file CameraCv.cxx.

References rnr::CamResDft, rnr::CamResQVGA, rnr::Camera::grabFrame(), rnr::CamRes::height, rnr::Camera::isCameraRunning(), rnr::Camera::isEqResolution(), rnr::Camera::m_bCameraRunning, rnr::Camera::m_bFatal, rnr::Camera::m_nVideoIndex, rnr::Camera::m_resCurrent, rnr::Camera::m_resVideo, rnr::Camera::m_strVideoDevName, rnr::Camera::setCameraResolution(), and rnr::CamRes::width.

Referenced by rnr::CameraGst::clickImage().

{
  CamRes  res = resVideo;
  Mat     img;

  // default is the current video resolution
  if( isEqResolution(res, CamResDft) )
  {
    res = m_resVideo;
  }

  errno = 0;

  // start video
  if( !isCameraRunning() )
  {
    // start OpenCV video capture
    if( !m_capture.open(m_nVideoIndex) )
    {
      LOGSYSERROR("%s: Could not open video device.",
          m_strVideoDevName.c_str());
      m_bFatal = true;
      return RC_ERROR;
    }
  }

  m_bCameraRunning = true;

  // always set video resolution else camera may default to an alternate size
  m_resVideo = setCameraResolution(res);

  //
  // Grab a frame into internal buffer to get the actual resolution.
  //
  if( grabFrame(img) < 0 )
  {
    LOGERROR("Cannot determine captured image size, using defaults"); 
    m_resVideo = CamResQVGA;
  }

  // set actual resolution
  else 
  {
    m_resVideo.width  = img.cols;
    m_resVideo.height = img.rows;
  }

  // update current to match video
  m_resCurrent = m_resVideo;

  LOGDIAG3("Capturing %dx%d video.", m_resVideo.width, m_resVideo.height);

  return OK;
}

int CameraCv::stopVideo ( )

virtual

Stop the camera from streaming video.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Reimplemented from rnr::Camera.

Definition at line 144 of file CameraCv.cxx.

References rnr::Camera::isCameraRunning(), and rnr::Camera::m_bCameraRunning.

Referenced by rnr::CameraGst::clickImage(), and rnr::CameraGst::~CameraGst().

{
  if( !isCameraRunning() )
  {
    LOGDIAG3("Video capture already stoped.");
    return OK;
  }

  // capture frame will be released here also
  m_capture.release();

  m_bCameraRunning = false;

  LOGDIAG3("Video capturing stopped.");
}

---

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

• include/rnr/appkit/CameraCv.h
• sw/librnr_cam/CameraCv.cxx