Generates calibration table description file and corresponding PostScript file.
create_caltab generates the description of a plane calibration table. This calibration table consists of 49 black circular marks on a white plane, which are surrounded by a black frame. The parameter Width sets the width (equal to the height) of the whole calibration table in meter. Using a width of 0.8 m the distance between two neighboring marks becomes 10 cm, and the mark radius and the frame width are set to 2.5 cm.
The file CalTabDescrFile contains the calibration table description, e.g., the number of rows and columns of the calibration table, the geometry of the surrounding frame (vgl. find_caltab), and the coordinates and the radius of all calibration table marks given in the calibration table coordinate system. A file generated by create_caltab looks like the following (comments are marked by a '' at the beginning of a line):
# # Description of the standard calibration table # used for the CCD-camera calibration in HORUS # (generated by create_caltab()) # # HORUS version 4.11 -- Fri Feb 7 16:13:56 1997 # # 7 rows X 7 columns # Distance between mark centers [meter]: 0.1 # Number of marks per row r 7 # Number of marks per column c 7 # Quadratic frame (with outer and inner border) around calibration table w 0.025 o -0.41 0.41 0.41 -0.41 i -0.4 0.4 0.4 -0.4 # calibration marks: x y radius [Meter] # calibration marks at y = -0.3 m -0.3 -0.3 0.025 -0.2 -0.3 0.025 -0.1 -0.3 0.025 0 -0.3 0.025 0.1 -0.3 0.025 0.2 -0.3 0.025 0.3 -0.3 0.025 # calibration marks at y = -0.2 m -0.3 -0.2 0.025 -0.2 -0.2 0.025 -0.1 -0.2 0.025 0 -0.2 0.025 0.1 -0.2 0.025 0.2 -0.2 0.025 0.3 -0.2 0.025 # calibration marks at y = -0.1 m -0.3 -0.1 0.025 -0.2 -0.1 0.025 -0.1 -0.1 0.025 0 -0.1 0.025 0.1 -0.1 0.025 0.2 -0.1 0.025 0.3 -0.1 0.025 # calibration marks at y = 0 m -0.3 0 0.025 -0.2 0 0.025 -0.1 0 0.025 0 0 0.025 0.1 0 0.025 0.2 0 0.025 0.3 0 0.025 # calibration marks at y = 0.1 m -0.3 0.1 0.025 -0.2 0.1 0.025 -0.1 0.1 0.025 0 0.1 0.025 0.1 0.1 0.025 0.2 0.1 0.025 0.3 0.1 0.025 # calibration marks at y = 0.2 m -0.3 0.2 0.025 -0.2 0.2 0.025 -0.1 0.2 0.025 0 0.2 0.025 0.1 0.2 0.025 0.2 0.2 0.025 0.3 0.2 0.025 # calibration marks at y = 0.3 m -0.3 0.3 0.025 -0.2 0.3 0.025 -0.1 0.3 0.025 0 0.3 0.025 0.1 0.3 0.025 0.2 0.3 0.025 0.3 0.3 0.025The file CalTabFile contains the corresponding PostScript description of the calibration table.
Dependent on the accuracy of the used output device (e.g. laser printer) the printed calibration table may not match the values in the calibration table descripton file CalTabDescrFile exactly. Thus, the coordinates of the calibration marks in the calibration table descripton file have to be corrected!
Width (input_control) |
real -> real |
Width of the calibration table in meter. | |
Default value: 0.8 | |
Suggested values: 1.2, 0.8, 0.6, 0.4, 0.2, 0.1 | |
Recommended increment: 0.1 | |
Restriction: 0.0 < Width |
CalTabDescrFile (input_control) |
string -> string |
File name of the calibration table description. | |
Default value: 'caltab.descr' |
CalTabFile (input_control) |
string -> string |
File name of the PostSript file. | |
Default value: 'caltab.ps' |
/* create calibration table with width = 80 cm */ create_caltab(::0.8,'caltab.descr','caltab.ps').
create_caltab returns TRUE if all parameter values are correct and both files have been written successfully. If necessary an exception is raised.
find_caltab, find_marks_and_pose, camera_calibration, disp_caltab, sim_caltab