Operator Reference

HALCON Operator Reference / XLD / Transformations

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union_straight_contours_xldunion_straight_contours_xldUnionStraightContoursXldUnionStraightContoursXldunion_straight_contours_xld (Operator)

union_straight_contours_xldunion_straight_contours_xldUnionStraightContoursXldUnionStraightContoursXldunion_straight_contours_xld — Compute the union of neighboring straight contours that have a similar direction.

Signature

union_straight_contours_xld(Contours : UnionContours : MaxDist, MaxDiff, Percent, Mode, Iterations : )

Herror union_straight_contours_xld(const Hobject Contours, Hobject* UnionContours, double MaxDist, double MaxDiff, double Percent, const char* Mode, const char* Iterations)

Herror T_union_straight_contours_xld(const Hobject Contours, Hobject* UnionContours, const Htuple MaxDist, const Htuple MaxDiff, const Htuple Percent, const Htuple Mode, const Htuple Iterations)

void UnionStraightContoursXld(const HObject& Contours, HObject* UnionContours, const HTuple& MaxDist, const HTuple& MaxDiff, const HTuple& Percent, const HTuple& Mode, const HTuple& Iterations)

HXLDCont HXLDCont::UnionStraightContoursXld(double MaxDist, double MaxDiff, double Percent, const HString& Mode, const HTuple& Iterations) const

HXLDCont HXLDCont::UnionStraightContoursXld(double MaxDist, double MaxDiff, double Percent, const HString& Mode, const HString& Iterations) const

HXLDCont HXLDCont::UnionStraightContoursXld(double MaxDist, double MaxDiff, double Percent, const char* Mode, const char* Iterations) const

HXLDCont HXLDCont::UnionStraightContoursXld(double MaxDist, double MaxDiff, double Percent, const wchar_t* Mode, const wchar_t* Iterations) const   ( Windows only)

static void HOperatorSet.UnionStraightContoursXld(HObject contours, out HObject unionContours, HTuple maxDist, HTuple maxDiff, HTuple percent, HTuple mode, HTuple iterations)

HXLDCont HXLDCont.UnionStraightContoursXld(double maxDist, double maxDiff, double percent, string mode, HTuple iterations)

HXLDCont HXLDCont.UnionStraightContoursXld(double maxDist, double maxDiff, double percent, string mode, string iterations)

def union_straight_contours_xld(contours: HObject, max_dist: float, max_diff: float, percent: float, mode: str, iterations: Union[int, str]) -> HObject

Description

union_straight_contours_xldunion_straight_contours_xldUnionStraightContoursXldUnionStraightContoursXldunion_straight_contours_xld merges neighboring XLD contours ContoursContoursContourscontourscontours if certain criteria are fulfilled. At each iteration, at most two contours that fulfill the given criteria are merged. The parameter IterationsIterationsIterationsiterationsiterations controls how often this step is executed.

Two contours are merged if the shortest distance between their end points (end points are the projections of the contours' first and last points onto its regression line) is smaller than MaxDistMaxDistMaxDistmaxDistmax_dist, and if the difference in direction (i.e., the regression lines' direction) is smaller than MaxDiffMaxDiffMaxDiffmaxDiffmax_diff (radians).

If only one of the criteria is fulfilled, the decision on merging can be influenced by the weighting factor PercentPercentPercentpercentpercent, which allows the exceeding of one limit to be balanced by the other value remaining below the limit by the same amount. The end point distance is weighted by PercentPercentPercentpercentpercent, while the directional difference is weighted by 100 - PercentPercentPercentpercentpercent.

This means that two contours are merged if they fulfill the following condition:

If, for example, two contours have an end point distance of 5.0 and a directional difference of 0.5 (with the limits chosen being MaxDistMaxDistMaxDistmaxDistmax_dist = 4.0 and MaxDiffMaxDiffMaxDiffmaxDiffmax_diff = 0.625), both values differ from the limits by 25%. By choosing PercentPercentPercentpercentpercent = 60%, the larger end point distance is weighted more than the smaller directional difference, and thus the contours are not merged. Contrary, if PercentPercentPercentpercentpercent = 40% is chosen, the contours are merged.

For PercentPercentPercentpercentpercent = 100%, only the end point distance is taken into account, while for PercentPercentPercentpercentpercent = 0% only the difference of direction is used. If PercentPercentPercentpercentpercent = 50% both criteria are equally valid.

In case there are parallel contours, there is a danger of merging neighboring contours. If this is to be avoided, ModeModeModemodemode = 'noparallel'"noparallel""noparallel""noparallel""noparallel" has to be chosen, while otherwise ModeModeModemodemode = 'paralleltoo'"paralleltoo""paralleltoo""paralleltoo""paralleltoo" suffices. For ModeModeModemodemode = 'every'"every""every""every""every", contours are merged unconditionally. All other parameters have no influence in this case.

The parameters of the regression line are calculated anew for merged contours.

Attention

Before contours can be united by union_straight_contours_xldunion_straight_contours_xldUnionStraightContoursXldUnionStraightContoursXldunion_straight_contours_xld, the parameters of the regression lines to the contours must be calculated by calling regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldregress_contours_xld.

Furthermore, note that union_straight_contours_xldunion_straight_contours_xldUnionStraightContoursXldUnionStraightContoursXldunion_straight_contours_xld can not compute the union of contours with different contour point attributes. This can be the case if different operators are used for the contour extraction (e.g., lines_gausslines_gaussLinesGaussLinesGausslines_gauss and lines_facetlines_facetLinesFacetLinesFacetlines_facet). For information on the contour attributes and when they are defined, see the respective operator reference. You can query the point attributes of your contour using query_contour_attribs_xldquery_contour_attribs_xldQueryContourAttribsXldQueryContourAttribsXldquery_contour_attribs_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

ContoursContoursContourscontourscontours (input_object)  xld_cont-array → objectHXLDContHObjectHObjectHobject

Input XLD contours.

UnionContoursUnionContoursUnionContoursunionContoursunion_contours (output_object)  xld_cont-array → objectHXLDContHObjectHObjectHobject *

Output XLD contours.

MaxDistMaxDistMaxDistmaxDistmax_dist (input_control)  real → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Maximum distance of the contours' endpoints.

Default: 5.0

MaxDiffMaxDiffMaxDiffmaxDiffmax_diff (input_control)  angle.rad → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Maximum difference in direction.

Default: 0.5

PercentPercentPercentpercentpercent (input_control)  real → HTuplefloatHTupleHtuple (real) (double) (double) (double)

Weighting factor for the two selection criteria.

Default: 50.0

ModeModeModemodemode (input_control)  string → HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Should parallel contours be taken into account?

Default: 'noparallel' "noparallel" "noparallel" "noparallel" "noparallel"

List of values: 'every'"every""every""every""every", 'noparallel'"noparallel""noparallel""noparallel""noparallel", 'paralleltoo'"paralleltoo""paralleltoo""paralleltoo""paralleltoo"

IterationsIterationsIterationsiterationsiterations (input_control)  string → HTupleUnion[int, str]HTupleHtuple (string / integer) (string / int / long) (HString / Hlong) (char* / Hlong)

Number of iterations or 'maximum'.

Default: 'maximum' "maximum" "maximum" "maximum" "maximum"

Suggested values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 'maximum'"maximum""maximum""maximum""maximum"

Value range: 1 ≤ Iterations Iterations Iterations iterations iterations ≤ 500 (lin)

Minimum increment: 1

Recommended increment: 1

Possible Predecessors

regress_contours_xldregress_contours_xldRegressContoursXldRegressContoursXldregress_contours_xld

Alternatives

union_collinear_contours_xldunion_collinear_contours_xldUnionCollinearContoursXldUnionCollinearContoursXldunion_collinear_contours_xld, union_collinear_contours_ext_xldunion_collinear_contours_ext_xldUnionCollinearContoursExtXldUnionCollinearContoursExtXldunion_collinear_contours_ext_xld, union_cocircular_contours_xldunion_cocircular_contours_xldUnionCocircularContoursXldUnionCocircularContoursXldunion_cocircular_contours_xld, union_cotangential_contours_xldunion_cotangential_contours_xldUnionCotangentialContoursXldUnionCotangentialContoursXldunion_cotangential_contours_xld, union_adjacent_contours_xldunion_adjacent_contours_xldUnionAdjacentContoursXldUnionAdjacentContoursXldunion_adjacent_contours_xld

See also

fit_line_contour_xldfit_line_contour_xldFitLineContourXldFitLineContourXldfit_line_contour_xld, get_contour_xldget_contour_xldGetContourXldGetContourXldget_contour_xld, get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldget_contour_attrib_xld, gen_contours_skeleton_xldgen_contours_skeleton_xldGenContoursSkeletonXldGenContoursSkeletonXldgen_contours_skeleton_xld, lines_gausslines_gaussLinesGaussLinesGausslines_gauss, lines_facetlines_facetLinesFacetLinesFacetlines_facet, edges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPixedges_sub_pix, get_regress_params_xldget_regress_params_xldGetRegressParamsXldGetRegressParamsXldget_regress_params_xld, get_contour_global_attrib_xldget_contour_global_attrib_xldGetContourGlobalAttribXldGetContourGlobalAttribXldget_contour_global_attrib_xld, query_contour_global_attribs_xldquery_contour_global_attribs_xldQueryContourGlobalAttribsXldQueryContourGlobalAttribsXldquery_contour_global_attribs_xld

Module

Foundation

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ClassesClasses | | Operators