vpXmlParserCamera Class Reference

#include <vpXmlParserCamera.h>

Public Types
enum	vpXmlCodeSequenceType { SEQUENCE_OK, SEQUENCE_ERROR }

Public Member Functions
	vpXmlParserCamera ()
	~vpXmlParserCamera ()
std::string	getCameraName () const
vpCameraParameters	getCameraParameters () const
unsigned int	getHeight () const
unsigned int	getSubsampling_width () const
unsigned int	getSubsampling_height () const
unsigned int	getWidth () const
int	parse (vpCameraParameters &cam, const std::string &filename, const std::string &camera_name, const vpCameraParameters::vpCameraParametersProjType &projModel, unsigned int image_width=0, unsigned int image_height=0)
int	save (const vpCameraParameters &cam, const std::string &filename, const std::string &camera_name, unsigned int image_width=0, unsigned int image_height=0, const std::string &additionalInfo="")
void	setCameraName (const std::string &name)
void	setHeight (unsigned int height)
void	setSubsampling_width (unsigned int subsampling)
void	setSubsampling_height (unsigned int subsampling)
void	setWidth (unsigned int width)

Detailed Description

XML parser to load and save intrinsic camera parameters.

To have a complete description of the camera parameters and the corresponding projection model implemented in ViSP, see vpCameraParameters.

Example of an XML file "myXmlFile.xml" containing intrinsic camera parameters:

<?xml version="1.0"?>
<root>
  <camera>
    <name>myCamera</name>
    <image_width>640</image_width>
    <image_height>480</image_height>
    <model>
      <type>perspectiveProjWithoutDistortion</type>
      <px>1129.0</px>
      <py>1130.6</py>
      <u0>317.9</u0>
      <v0>229.1</v0>
    </model>
    <model>
      <type>perspectiveProjWithDistortion</type>
      <px>1089.9</px>
      <py>1090.1</py>
      <u0>326.1</u0>
      <v0>230.5</v0>
      <kud>-0.196</kud>
      <kdu>0.204</kdu>
    </model>
  </camera>
</root>

Example of loading existing camera parameters from an XML file:

#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpXmlParserCamera.h>

int main()
{
  vpCameraParameters cam; // Create a camera parameter container
  vpXmlParserCamera p; // Create a XML parser
  vpCameraParameters::vpCameraParametersProjType projModel; // Projection model
  // Use a perspective projection model without distortion
  projModel = vpCameraParameters::perspectiveProjWithoutDistortion;
  // Parse the xml file "myXmlFile.xml" to find the intrinsic camera
  // parameters of the camera named "myCamera" for the image sizes 640x480,
  // for the projection model projModel. The size of the image is optional
  // if camera parameters are given only for one image size.
  if (p.parse(cam, "myXmlFile.xml", "myCamera", projModel,640,480) != vpXmlParserCamera::SEQUENCE_OK) {
   std::cout << "Cannot found myCamera" << std::endl;
  }

  // cout the parameters
  cam.printParameters();

  // Get the camera parameters for the model without distortion
  double px = cam.get_px();
  double py = cam.get_py();
  double u0 = cam.get_u0();
  double v0 = cam.get_v0();

  // Now we modify the principal point (u0,v0) for example to add noise
  u0 *= 0.9;
  v0 *= 0.8;

  // Set the new camera parameters
  cam.initPersProjWithoutDistortion(px, py, u0, v0);

  // Save the parameters in a new file "myXmlFileWithNoise.xml"
  p.save(cam,"myXmlFileWithNoise.xml",p.getCameraName(),p.getWidth(),p.getHeight());
}

Example of writing an XML file containing intrinsic camera parameters:

#include <visp3/core/vpCameraParameters.h>
#include <visp3/core/vpXmlParserCamera.h>

int main()
{
  // Create a camera parameter container. We want to set these parameters
  // for a 320x240 image, and we want to use the perspective projection
  // modelisation without distortion.
  vpCameraParameters cam;

  // Set the principal point coordinates (u0,v0)
  double u0 = 162.3;
  double v0 = 122.4;
  // Set the pixel ratio (px, py)
  double px = 563.2;
  double py = 564.1;

  // Set the camera parameters for a model without distortion
  cam.initPersProjWithoutDistortion(px, py, u0, v0);

  // Create a XML parser
  vpXmlParserCamera p;
  // Save the camera parameters in an XML file.
  if (p.save(cam, "myNewXmlFile.xml", "myNewCamera", 320, 240) != vpXmlParserCamera::SEQUENCE_OK) {
    std::cout << "Cannot save camera parameters" << std::endl;
  }
}

Examples:

mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, servoBebop2.cpp, servoFlirPtuIBVS.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-chessboard-pose.cpp, tutorial-franka-acquire-calib-data.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-pose-from-points-live.cpp, and tutorial-undistort.cpp.

Definition at line 164 of file vpXmlParserCamera.h.

Member Enumeration Documentation

enum vpXmlParserCamera::vpXmlCodeSequenceType

Enumerator
SEQUENCE_OK
SEQUENCE_ERROR

Definition at line 167 of file vpXmlParserCamera.h.

Constructor & Destructor Documentation

vpXmlParserCamera::vpXmlParserCamera

(

)

Definition at line 1073 of file vpXmlParserCamera.cpp.

vpXmlParserCamera::~vpXmlParserCamera

(

)

Definition at line 1077 of file vpXmlParserCamera.cpp.

Member Function Documentation

std::string vpXmlParserCamera::getCameraName

(

)

const

Definition at line 1153 of file vpXmlParserCamera.cpp.

vpCameraParameters vpXmlParserCamera::getCameraParameters

(

)

const

Definition at line 1158 of file vpXmlParserCamera.cpp.

unsigned int vpXmlParserCamera::getHeight

(

)

const

Definition at line 1163 of file vpXmlParserCamera.cpp.

unsigned int vpXmlParserCamera::getSubsampling_height

(

)

const

Definition at line 1173 of file vpXmlParserCamera.cpp.

unsigned int vpXmlParserCamera::getSubsampling_width

(

)

const

Definition at line 1168 of file vpXmlParserCamera.cpp.

unsigned int vpXmlParserCamera::getWidth

(

)

const

Definition at line 1178 of file vpXmlParserCamera.cpp.

int vpXmlParserCamera::parse	(	vpCameraParameters &	cam,
		const std::string &	filename,
		const std::string &	cam_name,
		const vpCameraParameters::vpCameraParametersProjType &	projModel,
		unsigned int	im_width = 0,
		unsigned int	im_height = 0
	)

Parse an xml file to load camera parameters.

Parameters

cam	: camera parameters to fill.
filename	: name of the xml file to parse
cam_name	: name of the camera : useful if the xml file has multiple camera parameters. Set as "" if the camera name is not ambiguous.
projModel	: camera projection model needed.
im_width	: image width on which camera calibration was performed. Set as 0 if not ambiguous.
im_height	: image height on which camera calibration was performed. Set as 0 if not ambiguous.

Returns

vpXmlParserCamera::SEQUENCE_OK if success and vpXmlParserCamera::SEQUENCE_ERROR otherwise.

Examples:

mbot-apriltag-2D-half-vs.cpp, mbot-apriltag-ibvs.cpp, mbot-apriltag-pbvs.cpp, servoBebop2.cpp, servoFlirPtuIBVS.cpp, tutorial-apriltag-detector-live.cpp, tutorial-apriltag-detector.cpp, tutorial-chessboard-pose.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-live.cpp, and tutorial-undistort.cpp.

Definition at line 1096 of file vpXmlParserCamera.cpp.

Referenced by vpViper650::getCameraParameters(), vpViper850::getCameraParameters(), vpAfma6::getCameraParameters(), and vpKinect::start().

int vpXmlParserCamera::save	(	const vpCameraParameters &	cam,
		const std::string &	filename,
		const std::string &	cam_name,
		unsigned int	im_width = 0,
		unsigned int	im_height = 0,
		const std::string &	additionalInfo = ""
	)

Save camera parameters in an xml file.

Parameters

cam	: camera parameters to save.
filename	: name of the xml file to fill.
cam_name	: name of the camera : useful if the xml file has multiple camera parameters. Set as "" if the camera name is not ambiguous.
im_width	: width of image on which camera calibration was performed. Set as 0 if not ambiguous.
im_height	: height of the image on which camera calibration was performed. Set as 0 if not ambiguous.
additionalInfo	: Additional information added in the saved xml file. The content of this string should be in xml format.

Returns

error code.

A typical usage would be the following:

#include <visp3/core/vpTime.h>
#include <visp3/core/vpXmlParserCamera.h>

int main()
{
  vpCameraParameters cam;
  std::stringstream ss_additional_info;
  ss_additional_info << "<date>" << vpTime::getDateTime() << "</date>";

  vpXmlParserCamera p;
  if (p.save(cam, "camera.xml", "myCamera", 320, 240, ss_additional_info.str()) != vpXmlParserCamera::SEQUENCE_OK) {
    std::cout << "Cannot save camera parameters" << std::endl;
  }
}

In camera.xml file, you will see:

<camera>
  ...
  <!--Additional information-->
  <additional_information>
    <date>2016/06/10 09:15:56</date>
  </additional_information>
</camera>

Examples:

tutorial-franka-acquire-calib-data.cpp.

Definition at line 1146 of file vpXmlParserCamera.cpp.

void vpXmlParserCamera::setCameraName

(

const std::string &

name

)

Definition at line 1183 of file vpXmlParserCamera.cpp.

void vpXmlParserCamera::setHeight

(

unsigned int

height

)

Definition at line 1188 of file vpXmlParserCamera.cpp.

void vpXmlParserCamera::setSubsampling_height

(

unsigned int

subsampling

)

Definition at line 1198 of file vpXmlParserCamera.cpp.

void vpXmlParserCamera::setSubsampling_width

(

unsigned int

subsampling

)

Definition at line 1193 of file vpXmlParserCamera.cpp.

void vpXmlParserCamera::setWidth

(

unsigned int

width

)

Definition at line 1203 of file vpXmlParserCamera.cpp.