distance_contours_xlddistance_contours_xldDistanceContoursXldDistanceContoursXlddistance_contours_xld (Operator)

Name

distance_contours_xlddistance_contours_xldDistanceContoursXldDistanceContoursXlddistance_contours_xld — Calculate the pointwise distance from one contour to another.

Signature

distance_contours_xld(ContourFrom, ContourTo : ContourOut : Mode : )

Description

The operator distance_contours_xlddistance_contours_xldDistanceContoursXldDistanceContoursXldDistanceContoursXlddistance_contours_xld calculates for each point in ContourFromContourFromContourFromContourFromcontourFromcontour_from the minimal distance to the contours in ContourToContourToContourToContourTocontourTocontour_to. The operator returns the contour ContourOutContourOutContourOutContourOutcontourOutcontour_out which consists of ContourFromContourFromContourFromContourFromcontourFromcontour_from containing the computed distances in the attribute 'distance'"distance""distance""distance""distance""distance". The distances can be accessed by querying the attribute 'distance'"distance""distance""distance""distance""distance" with the operator get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldGetContourAttribXldget_contour_attrib_xld. See the operator reference of get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldGetContourAttribXldget_contour_attrib_xld for further information about contour attributes.

The parameter ModeModeModeModemodemode determines which distances are calculated for each point in ContourFromContourFromContourFromContourFromcontourFromcontour_from: 'point_to_point'"point_to_point""point_to_point""point_to_point""point_to_point""point_to_point" calculates the minimal distance to the base points of ContourToContourToContourToContourTocontourTocontour_to. In contrast, 'point_to_segment'"point_to_segment""point_to_segment""point_to_segment""point_to_segment""point_to_segment" calculates the minimum distance to the contour segments in ContourToContourToContourToContourTocontourTocontour_to (see the figure below).

The dashed lines illustrate the calculated distances starting from a point of ContourFromContourFromContourFromContourFromcontourFromcontour_from on the left. The distance corresponds to the 'point_to_point'"point_to_point""point_to_point""point_to_point""point_to_point""point_to_point" mode, whereas the distance corresponds to the 'point_to_segment'"point_to_segment""point_to_segment""point_to_segment""point_to_segment""point_to_segment" mode.

Note that in many applications the mode 'point_to_segment'"point_to_segment""point_to_segment""point_to_segment""point_to_segment""point_to_segment" suggests itself for an accurate result, whereas 'point_to_point'"point_to_point""point_to_point""point_to_point""point_to_point""point_to_point" is considerably faster. If m is the number of points in ContourFromContourFromContourFromContourFromcontourFromcontour_from, and n the number of points in ContourToContourToContourToContourTocontourTocontour_to, then distance_contours_xlddistance_contours_xldDistanceContoursXldDistanceContoursXldDistanceContoursXlddistance_contours_xld has complexity O(mlog(n)) for 'point_to_point'"point_to_point""point_to_point""point_to_point""point_to_point""point_to_point", and O(mn) for 'point_to_segment'"point_to_segment""point_to_segment""point_to_segment""point_to_segment""point_to_segment". In case the template contour ContourToContourToContourToContourTocontourTocontour_to is repeatedly used, the operators create_distance_transform_xldcreate_distance_transform_xldCreateDistanceTransformXldCreateDistanceTransformXldCreateDistanceTransformXldcreate_distance_transform_xld and apply_distance_transform_xldapply_distance_transform_xldApplyDistanceTransformXldApplyDistanceTransformXldApplyDistanceTransformXldapply_distance_transform_xld can be used as an alternative to distance_contours_xlddistance_contours_xldDistanceContoursXldDistanceContoursXldDistanceContoursXlddistance_contours_xld. For further details, please refer to the documentation of create_distance_transform_xldcreate_distance_transform_xldCreateDistanceTransformXldCreateDistanceTransformXldCreateDistanceTransformXldcreate_distance_transform_xld.

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

ContourFromContourFromContourFromContourFromcontourFromcontour_from (input_object) xld_cont(-array) → object

Contours for whose points the distances are calculated.

ContourToContourToContourToContourTocontourTocontour_to (input_object) xld_cont(-array) → object

Contours to which the distances are calculated to.

ContourOutContourOutContourOutContourOutcontourOutcontour_out (output_object) xld_cont(-array) → object

Copy of ContourFromContourFromContourFromContourFromcontourFromcontour_from containing the distances as an attribute.

ModeModeModeModemodemode (input_control) string → (string)

Compute the distance to points ('point_to_point') or to entire segments ('point_to_segment').

Default value: 'point_to_point' "point_to_point" "point_to_point" "point_to_point" "point_to_point" "point_to_point"

List of values: 'point_to_point'"point_to_point""point_to_point""point_to_point""point_to_point""point_to_point", 'point_to_segment'"point_to_segment""point_to_segment""point_to_segment""point_to_segment""point_to_segment"

Result

If all parameters are correct, the operator returns the value 2 (H_MSG_TRUE). Otherwise, an exception is raised.

Possible Successors

get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldGetContourAttribXldget_contour_attrib_xld, segment_contour_attrib_xldsegment_contour_attrib_xldSegmentContourAttribXldSegmentContourAttribXldSegmentContourAttribXldsegment_contour_attrib_xld

Alternatives

apply_distance_transform_xldapply_distance_transform_xldApplyDistanceTransformXldApplyDistanceTransformXldApplyDistanceTransformXldapply_distance_transform_xld, distance_ccdistance_ccDistanceCcDistanceCcDistanceCcdistance_cc, distance_cc_mindistance_cc_minDistanceCcMinDistanceCcMinDistanceCcMindistance_cc_min

Module

Foundation

Operators