XmlParserCamera¶

class XmlParserCamera(self)¶

Bases: pybind11_object

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
  // modelization 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;
  }
}

Methods

`__init__`
`getCameraName`
`getCameraParameters`
`getHeight`
`getSubsampling_height`
`getSubsampling_width`
`getWidth`
`parse`	param cam: Camera parameters to fill.
`save`	A typical usage would be the following:
`setCameraName`
`setHeight`
`setSubsampling_height`
`setSubsampling_width`
`setWidth`

Inherited Methods

Operators

`__doc__`
`__init__`
`__module__`

Attributes

`SEQUENCE_ERROR`
`SEQUENCE_OK`
`__annotations__`

class XmlCodeSequenceType(self, value: int)¶

Bases: pybind11_object

Values:

SEQUENCE_OK
SEQUENCE_ERROR

__and__(self, other: object) → object¶

__eq__(self, other: object) → bool¶

__ge__(self, other: object) → bool¶

__getstate__(self) → int¶

__gt__(self, other: object) → bool¶

__hash__(self) → int¶

__index__(self) → int¶

__init__(self, value: int)¶

__int__(self) → int¶

__invert__(self) → object¶

__le__(self, other: object) → bool¶

__lt__(self, other: object) → bool¶

__ne__(self, other: object) → bool¶

__or__(self, other: object) → object¶

__rand__(self, other: object) → object¶

__ror__(self, other: object) → object¶

__rxor__(self, other: object) → object¶

__setstate__(self, state: int) → None¶

__xor__(self, other: object) → object¶

property name : str¶

__init__(self)¶

getCameraName(self) → str¶

getCameraParameters(self) → visp._visp.core.CameraParameters¶

getHeight(self) → int¶

getSubsampling_height(self) → int¶

getSubsampling_width(self) → int¶

getWidth(self) → int¶

parse(self, cam: visp._visp.core.CameraParameters, filename: str, camera_name: str, projModel: visp._visp.core.CameraParameters.CameraParametersProjType, image_width: int = 0, image_height: int = 0, verbose: bool = true) → int¶

Parameters:

cam: visp._visp.core.CameraParameters¶: Camera parameters to fill.
filename: str¶: Name of the xml file to parse.
projModel: visp._visp.core.CameraParameters.CameraParametersProjType¶: Camera projection model needed.
verbose: bool = true¶: true to enable verbose mode, false otherwise.

Returns:

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

save(self: visp._visp.core.XmlParserCamera, cam: visp._visp.core.CameraParameters, filename: str, camera_name: str, image_width: int = 0, image_height: int = 0, additionalInfo: str =, verbose: bool = true) → int¶

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>

Parameters:

cam: Camera parameters to save.
filename: Name of the xml file to fill.
additionalInfo: Additional information added in the saved xml file. The content of this string should be in xml format.
verbose: true to enable verbose mode, false otherwise.

Returns:

error code.

setCameraName(self, name: str) → None¶

setHeight(self, height: int) → None¶

setSubsampling_height(self, subsampling: int) → None¶

setSubsampling_width(self, subsampling: int) → None¶

setWidth(self, width: int) → None¶