Transform an XLD contour into the plane z=0 of a world coordinate system.
The operator contour_to_world_plane_xld transforms contour points given in Contours into the plane z=0 in a world coordinate system and returns the 3D contour points in ContoursTrans. The world coordinate system is chosen by passing its 3D pose relative to the camera coordinate system in WorldPose. In CamParam you must pass the interior camera parameters (see write_cam_par for the sequence of the parameters and the underlying camera model).
In many cases CamParam and WorldPose are the result of calibrating the camera with the operator camera_calibration. See below for an example.
With the parameter Scale you can scale the resulting 3D coordinates. The parameter Scale must be specified as the ratio desired unit/original unit. The original unit is determined by the coordinates of the calibration object. If the original unit is meters (which is the case if you use the standard calibration plate), you can set the desired unit directly by selecting 'm', 'cm', 'mm' or 'µm' for the parameter Scale.
Internally, the operator first computes the line of sight between the projection center and the image point in the camera coordinate system, taking into account the radial distortions. The line of sight is then transformed into the world coordinate system specified in WorldPose. By intersecting the plane z=0 with the line of sight the 3D coordinates of the transformed contour ContoursTrans are obtained.
|
Contours (input_object) |
xld_cont(-array) -> object |
| Input XLD contours to be transformed in image coordinates. | |
|
ContoursTrans (output_object) |
xld_cont(-array) -> object |
| Transformed XLD contours in world coordinates. | |
|
CamParam (input_control) |
number-array -> real / integer |
| Interior camera parameters. | |
| Number of elements: (CamParam == 8) || (CamParam == 11) | |
|
WorldPose (input_control) |
pose-array -> real / integer |
| 3D pose of the world coordinate system in camera coordinates. | |
| Number of elements: 7 | |
|
Scale (input_control) |
number -> string / integer / real |
| Scale oder dimension | |
| Default value: 'm' | |
| Suggested values: 'm', 'cm', 'mm', 'microns', 'µm', 1.0, 0.01, 0.001, '1.0e-6', 0.0254, 0.3048, 0.9144 | |
* perform camera calibration (with standard calibration plate)
camera_calibration(NX, NY, NZ, NRow, NCol, StartCamParam, NStartPose, 'all',
FinalCamParam, NFinalPose, Errors)
* world coordinate system is defined by calibration plate in first image
FinalPose1 := NFinalPose[0:6]
* compensate thickness of plate
set_origin_pose(FinalPose1, 0, 0, 0.0006, WorldPose)
* transform contours into world coordinate system (unit mm)
contour_to_world_plane_xld(Contours, ContoursTrans,
FinalCamParam, WorldPose, 'mm')
contour_to_world_plane_xld returns 2 (H_MSG_TRUE) if all parameter values are correct. If necessary, an exception handling is raised.
contour_to_world_plane_xld is reentrant and processed without parallelization.
create_pose, hom_mat3d_to_pose, camera_calibration, hand_eye_calibration, set_origin_pose
Calibration
