create_rectification_grid — Generate a PostScript file, which describes the rectification grid.
create_rectification_grid generates a checkered pattern with
NumSquares alternating black and white
squares. This pattern is
Width meters wide (and high). Around the
pattern there is an inner frame of 0.3 times the width of one
square, which continues the checkered pattern. The pattern is completed by
a solid white outer frame of 0.7 times the width of one square.
center of the pattern there are two circular marks, one black on a white
square and one white on a black square. The radius of both marks
correspond to one third of the side length of the respective enclosing
These marks are used by
gen_grid_rectification_map to rotate the
detected layout of the grid points into the correct orientation. It is
assumed that the black mark is positioned to the left of the
white mark, when oriented correctly.
GridFile contains the PostScript description of the
Width of the checkered pattern in meters (without the two frames).
Default value: 0.17
Suggested values: 1.2, 0.8, 0.6, 0.4, 0.2, 0.1
Recommended increment: 0.1
0.0 < Width
Number of squares per row and column.
Default value: 17
Suggested values: 11, 13, 15, 17, 19, 21, 23, 25, 27
Recommended increment: 2
2 <= NumSquares
File name of the PostScript file.
Default value: 'rectification_grid.ps'
File extension: .
find_rectification_grid returns 2 (H_MSG_TRUE) if all parameter values are
correct and the file has been written successfully. If necessary,
an exception is raised.