distance_contours_xld — Calculate the pointwise distance from one contour to another.
distance_contours_xld(ContourFrom, ContourTo : ContourOut : Mode : )
The operator distance_contours_xld calculates for each point in
ContourFrom the minimal distance to the contours in
ContourTo.
The operator returns the contour ContourOut which consists of
ContourFrom containing the computed distances in the
attribute 'distance'.
The distances can be accessed by querying the attribute
'distance' with the operator get_contour_attrib_xld.
See the operator reference of get_contour_attrib_xld for further
information about contour attributes.
The parameter
Mode determines which distances are calculated for each point
in ContourFrom:
'point_to_point' calculates the minimal distance to the base
points of ContourTo.
In contrast, 'point_to_segment' calculates the minimum
distance to the contour segments in ContourTo (see the figure
below).
ContourFrom on the left.
The distance corresponds to the
'point_to_point' mode, whereas the distance
corresponds to the 'point_to_segment' mode.
Note that in many applications the mode 'point_to_segment'
suggests itself for an accurate result, whereas
'point_to_point' is considerably faster.
If m is the number of points in ContourFrom, and n the number
of points in ContourTo, then distance_contours_xld
has complexity O(mlog(n)) for 'point_to_point', and O(mn) for
'point_to_segment'.
In case the template contour ContourTo is repeatedly used, the
operators create_distance_transform_xld and
apply_distance_transform_xld can be used as an alternative to
distance_contours_xld. For further details, please refer to
the documentation of create_distance_transform_xld.
ContourFrom (input_object) xld_cont(-array) → object
Contours for whose points the distances are calculated.
ContourTo (input_object) xld_cont(-array) → object
Contours to which the distances are calculated to.
ContourOut (output_object) xld_cont(-array) → object
Copy of ContourFrom containing the
distances as an attribute.
Mode (input_control) string → (string)
Compute the distance to points ('point_to_point') or to entire segments ('point_to_segment').
Default: 'point_to_point'
List of values: 'point_to_point', 'point_to_segment'
If all parameters are correct, the operator returns the value 2 ( H_MSG_TRUE) . Otherwise, an exception is raised.
get_contour_attrib_xld,
segment_contour_attrib_xld
apply_distance_transform_xld,
distance_cc,
distance_cc_min
Foundation