read_cam_par ( : : CamParFile : CamParam )

Read the internal camera parameters from text file.

read_cam_par is used to read the internal camera parameters CamParam from a text file with name CamParFile.

The format of the text file is a (HORUS-independent) generic parameter description. Thus, arbitrary sets of parameters can be grouped together in a hierarchical way. The description of a single parameter within a parameter group consists of the following 3 lines:

   Name : Shortname : Actual value ;
    Type : Lower bound (optional) : Upper bound (optional) ;
    Description (optional) ; 
The HORUS operator write_cam_par expects in the file CamParFile the parameter group Camera:Parameter. This parameter group consists of the 8 parameters Focus, Sx, Sy, Cx, Cy, Kappa , ImageWidth and ImageHeight. Comments are marked by a '' at the beginning of a line. A suitable file can look like the following:
  # INTERNAL CAMERA PARAMETERS

  ParGroup: Camera: Parameter;
      "Internal CCD-camera parameters";

  Focus:foc:      0.00806039;
      DOUBLE:0.0:;
      "Focal length of the lens [meter]";

  Sx:sx:  1.0629e-05;
      DOUBLE:0.0:;
      "Width of a cell on the CCD-chip [meter]";

  Sy:sy:  1.1e-05;
      DOUBLE:0.0:;
      "Height of a cell on the CCD-chip [meter]";

  Cx:cx:  378.236;
      DOUBLE:0.0:;
      "X-coordinate of the image center [pixel]";

  Cy:cy:  297.587;
      DOUBLE:0.0:;
      "Y-coordinate of the image center [pixel]";

  Kappa:kappa:    -2253.5;
      DOUBLE::;
      "Radial distortion coefficient [1/(meter*meter)]";

  ImageWidth:imgw:    768;
      INT:0:2048;
      "Width of the used calibration images [pixel]";

  ImageHeight:imgh:   576;
      INT:0:2048;
      "Height of the used calibration images [pixel]";
The underlying camera model is a pinhole camera with radial distortions. A detailled description of this camera model can be found within the description of write_cam_par.


Parameters

CamParFile (input_control)
string -> string
File name of internal camera parameters.
Default value: 'campar.dat'
List of values: 'campar.dat', 'campar.initial', 'campar.final'

CamParam (output_control)
number-array -> real / integer
Internal camera parameters.
Number of elements: 8


Example
/* get internal camera parameters: */
read_cam_par(::'campar.dat':CamParam).

Result

read_cam_par returns TRUE if all parameter values are correct and the file has been read successfully. If necessary an exception is raised.


Possible Successors

find_marks_and_pose, sim_caltab, create_caltab, disp_caltab, camera_calibration


See also

find_caltab, find_marks_and_pose, camera_calibration, disp_caltab, sim_caltab, write_cam_par, write_cam_pose, read_cam_pose, project_3d_point, inverse_project_pixel



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