complement — Return the complement of a region.
complement(Region : RegionComplement : : )
complement determines the complement of the input
region(s).
If the system flag 'clip_region' is 'true', which
is the default, the difference of the largest image processed so far
(see reset_obj_db) and the input region is returned.
If the system flag 'clip_region' is 'false' (see
set_system), the resluting region would be infinitely large.
To avoid this, the complement is done only virtually by setting
the complement flag of Region to TRUE. For succeeding
operations the de Morgan laws are applied while calculating results. Using
complement with 'clip_region' set to 'false' makes
sense only to avoid fringe effects, e.g., if the area of
interest is bigger or smaller than the image. For the latter case, the
clipping would be set explicitly. If there is no reason to use the
operator with 'clip_region'='false' but you need the flag
for other operations of your program, it is recommended to temporarilly set
the system flag to'true' and change it back to 'false'
after applying complement. Otherwise, negative regions may result
from succeeding operations.
Region (input_object) region(-array) → object
Input region(s).
RegionComplement (output_object) region(-array) → object
Complemented regions.
Number of elements: RegionComplement == Region
complement always returns the value 2 (H_MSG_TRUE). The
behavior in case of empty input (no regions given) can be set via
set_system('no_object_result',<Result>)
and the behavior in case of an empty input region via
set_system('empty_region_result',<Result>).
If necessary, an exception is raised.
threshold,
connection,
regiongrowing,
pouring,
class_ndim_norm
difference,
union1,
union2,
intersection,
reset_obj_db,
set_system
Foundation