gen_caltabgen_caltabGenCaltabGenCaltabgen_caltab (Operator)

Name

gen_caltabgen_caltabGenCaltabGenCaltabgen_caltab — Generate a calibration plate description file and a corresponding PostScript file for a calibration plate with rectangularly arranged marks.

Signature

Description

gen_caltabgen_caltabGenCaltabGenCaltabgen_caltab generates the description of a standard HALCON calibration plate with rectangularly arranged marks. This calibration plate consists of XNumXNumXNumXNumxnum times YNumYNumYNumYNumynum black circular marks on a white plane which are surrounded by a black frame.

The marks are arranged in a rectangular grid with YNumYNumYNumYNumynum and XNumXNumXNumXNumxnum equidistant rows and columns. The distances between these rows and columns defines the parameter MarkDistMarkDistMarkDistmarkDistmark_dist in meter. The marks' diameter can be set by the parameter DiameterRatioDiameterRatioDiameterRatiodiameterRatiodiameter_ratio and is defined by the equation . Using a distance between marks of 0.01 m and a diameter ratio of 0.5, the width of the dark surrounding frame becomes 8 cm, and the radius of the marks is set to 2.5 mm. The coordinate system of the calibration plate is located in the barycenter of all marks, its z-axis points into the calibration plate, its x-axis to the right, and its y-axis downwards.

The black frame of the calibration plate encloses a triangular black orientation mark in the top left corner to uniquely determine the position of the calibration plate. The width and the height of the generated calibration plate can be calculated with the following equations:

The file CalPlateDescrCalPlateDescrCalPlateDescrcalPlateDescrcal_plate_descr contains the calibration plate description, e.g., the number of rows and columns of the calibration plate, the geometry of the surrounding frame (see find_caltabfind_caltabFindCaltabFindCaltabfind_caltab), the triangular orientation mark, an offset of the coordinate system to the plate's surface in z-direction, and the x,y coordinates and the radius of all calibration plate marks given in the calibration plate coordinate system. The definition of the orientation and the offset, indicated by t and z, is optional and can be commented out. The default HALCON file extension for the calibration plate description is 'descr'. A file generated by gen_caltabgen_caltabGenCaltabGenCaltabgen_caltab looks like the following (comments are marked by a '#' at the beginning of a line): # Plate Description Version 2 # HALCON Version 7.1 -- Fri Jun 24 16:41:00 2005 # Description of the standard calibration plate # used for the camera calibration in HALCON # (generated by gen_caltab) # # # 7 rows x 7 columns # Width, height of the black frame [meter]: 0.1, 0.1 # Distance between mark centers [meter]: 0.0125 # Number of marks in y-dimension (rows) r 7 # Number of marks in x-dimension (columns) c 7 # offset of coordinate system in z-dimension [meter] (optional): z 0 # Rectangular border (rim and black frame) of calibration plate # rim of the calibration plate (min x, max y, max x, min y) [meter]: o -0.05125 0.05125 0.05125 -0.05125 # outer border of the black frame (min x, max y, max x, min y) [meter]: i -0.05 0.05 0.05 -0.05 # triangular corner mark given by two corner points (x,y, x,y) [meter] # (optional): t -0.05 -0.0375 -0.0375 -0.05 # width of the black frame [meter]: w 0.003125 # calibration marks: x y radius [meter] # calibration marks at y = -0.0375 m -0.0375 -0.0375 0.003125 -0.025 -0.0375 0.003125 -0.0125 -0.0375 0.003125 -3.46945e-018 -0.0375 0.003125 0.0125 -0.0375 0.003125 0.025 -0.0375 0.003125 0.0375 -0.0375 0.003125 # calibration marks at y = -0.025 m -0.0375 -0.025 0.003125 -0.025 -0.025 0.003125 -0.0125 -0.025 0.003125 -3.46945e-018 -0.025 0.003125 0.0125 -0.025 0.003125 0.025 -0.025 0.003125 0.0375 -0.025 0.003125 # calibration marks at y = -0.0125 m -0.0375 -0.0125 0.003125 -0.025 -0.0125 0.003125 -0.0125 -0.0125 0.003125 -3.46945e-018 -0.0125 0.003125 0.0125 -0.0125 0.003125 0.025 -0.0125 0.003125 0.0375 -0.0125 0.003125 # calibration marks at y = -3.46945e-018 m -0.0375 -3.46945e-018 0.003125 -0.025 -3.46945e-018 0.003125 -0.0125 -3.46945e-018 0.003125 -3.46945e-018 -3.46945e-018 0.003125 0.0125 -3.46945e-018 0.003125 0.025 -3.46945e-018 0.003125 0.0375 -3.46945e-018 0.003125 # calibration marks at y = 0.0125 m -0.0375 0.0125 0.003125 -0.025 0.0125 0.003125 -0.0125 0.0125 0.003125 -3.46945e-018 0.0125 0.003125 0.0125 0.0125 0.003125 0.025 0.0125 0.003125 0.0375 0.0125 0.003125 # calibration marks at y = 0.025 m -0.0375 0.025 0.003125 -0.025 0.025 0.003125 -0.0125 0.025 0.003125 -3.46945e-018 0.025 0.003125 0.0125 0.025 0.003125 0.025 0.025 0.003125 0.0375 0.025 0.003125 # calibration marks at y = 0.0375 m -0.0375 0.0375 0.003125 -0.025 0.0375 0.003125 -0.0125 0.0375 0.003125 -3.46945e-018 0.0375 0.003125 0.0125 0.0375 0.003125 0.025 0.0375 0.003125 0.0375 0.0375 0.003125 The file CalPlatePSFileCalPlatePSFileCalPlatePSFilecalPlatePSFilecal_plate_psfile contains the corresponding PostScript description of the calibration plate.

Attention

Depending on the accuracy of the used output device (e.g., laser printer), the printed calibration plate may not match the values in the calibration plate description file CalPlateDescrCalPlateDescrCalPlateDescrcalPlateDescrcal_plate_descr exactly. Thus, the coordinates of the calibration marks in the calibration plate description file may have to be corrected!

Execution Information

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

* Create calibration plate with width = 80 cm.
gen_caltab( 7, 7, 0.1, 0.5, 'caltab.descr', 'caltab.ps')

* Create calibration plate with width = 80 cm.
gen_caltab( 7, 7, 0.1, 0.5, 'caltab.descr', 'caltab.ps')

// Create calibration plate with width = 80 cm.
gen_caltab( 7, 7, 0.1, 0.5, "caltab.descr", "caltab.ps");

* Create calibration plate with width = 80 cm.
gen_caltab( 7, 7, 0.1, 0.5, 'caltab.descr', 'caltab.ps')

Result

gen_caltabgen_caltabGenCaltabGenCaltabgen_caltab returns 2 ( H_MSG_TRUE) if all parameter values are correct and both files have been written successfully. If necessary, an exception is raised.

Possible Successors

read_cam_parread_cam_parReadCamParReadCamParread_cam_par, caltab_pointscaltab_pointsCaltabPointsCaltabPointscaltab_points

Alternatives

create_caltabcreate_caltabCreateCaltabCreateCaltabcreate_caltab

See also

find_caltabfind_caltabFindCaltabFindCaltabfind_caltab, find_marks_and_posefind_marks_and_poseFindMarksAndPoseFindMarksAndPosefind_marks_and_pose, camera_calibrationcamera_calibrationCameraCalibrationCameraCalibrationcamera_calibration, disp_caltabdisp_caltabDispCaltabDispCaltabdisp_caltab, sim_caltabsim_caltabSimCaltabSimCaltabsim_caltab

Module

Foundation