ClassesClasses | | Operators

intersection_closed_contours_xldintersection_closed_contours_xldIntersectionClosedContoursXldIntersectionClosedContoursXld (Operator)

Name

intersection_closed_contours_xldintersection_closed_contours_xldIntersectionClosedContoursXldIntersectionClosedContoursXld — Intersect closed contours.

Signature

intersection_closed_contours_xld(Contours1, Contours2 : ContoursIntersection : : )

Herror intersection_closed_contours_xld(const Hobject Contours1, const Hobject Contours2, Hobject* ContoursIntersection)

Herror T_intersection_closed_contours_xld(const Hobject Contours1, const Hobject Contours2, Hobject* ContoursIntersection)

void IntersectionClosedContoursXld(const HObject& Contours1, const HObject& Contours2, HObject* ContoursIntersection)

HXLDCont HXLDCont::IntersectionClosedContoursXld(const HXLDCont& Contours2) const

static void HOperatorSet.IntersectionClosedContoursXld(HObject contours1, HObject contours2, out HObject contoursIntersection)

HXLDCont HXLDCont.IntersectionClosedContoursXld(HXLDCont contours2)

Description

The operator intersection_closed_contours_xldintersection_closed_contours_xldIntersectionClosedContoursXldIntersectionClosedContoursXldIntersectionClosedContoursXld calculates the intersection of the regions enclosed by the contours Contours1Contours1Contours1Contours1contours1 and Contours2Contours2Contours2Contours2contours2. The boundaries of this intersection are returned in ContoursIntersectionContoursIntersectionContoursIntersectionContoursIntersectioncontoursIntersection.

If the individual input contours are not closed, they are closed automatically by connecting their start and end points.

Internally, first, the regions enclosed by each set of contours (Contours1Contours1Contours1Contours1contours1 and Contours2Contours2Contours2Contours2contours2, respectively) are determined as described below. Then, the intersection of these two regions is calculated.

In the following, the two sets of input contours are referred to as boundary sets. A boundary set consists of an arbitrary number of boundaries (the individual contours of Contours1Contours1Contours1Contours1contours1 and Contours2Contours2Contours2Contours2contours2, respectively). Each boundary may be convex or concave and self-intersecting. Internal holes may be formed by the nesting of boundaries.

The region enclosed by such a boundary set is defined by the so-called Even-Odd-Rule. Thus, it consists of all points with the following property: The line constructed by connecting the point with another reference point that lies outside of the region has an odd number of intersections with boundaries.

More descriptive, this means that a boundary defines a hole in the region enclosed by another boundary if it lies completely inside that region. Similarly, the overlapping area of two separate boundaries of one boundary set is taken as a "hole", i.e., it does not belong to the region enclosed by the two boundaries. Note that the region enclosed by a boundary does not depend on the orientation of the boundary.

A self-intersecting boundary may be split at the intersection point or it is reordered such that it touches itself at the intersection point. The resulting boundaries are treated as separate boundaries.

The resulting boundaries ContoursIntersectionContoursIntersectionContoursIntersectionContoursIntersectioncontoursIntersection are automatically classified into boundaries that enclose regions and boundaries that enclose holes. This information is stored in the global contour attribute 'is_hole'"is_hole""is_hole""is_hole""is_hole". For boundaries that enclose holes, the global contour attribute 'is_hole'"is_hole""is_hole""is_hole""is_hole" is set to 1. Otherwise, it is set to 0.

Note that subsequent points whose row and column coordinates differ by less than 1e-06 pixels are considered as one point.

Execution Information

Parameters

Contours1Contours1Contours1Contours1contours1 (input_object)  xld_cont(-array) objectHXLDContHXLDContHobject

Contours enclosing the first region to be intersected.

Contours2Contours2Contours2Contours2contours2 (input_object)  xld_cont(-array) objectHXLDContHXLDContHobject

Contours enclosing the second region to be intersected.

ContoursIntersectionContoursIntersectionContoursIntersectionContoursIntersectioncontoursIntersection (output_object)  xld_cont(-array) objectHXLDContHXLDContHobject *

Contours enclosing the intersection.

Result

intersection_closed_contours_xldintersection_closed_contours_xldIntersectionClosedContoursXldIntersectionClosedContoursXldIntersectionClosedContoursXld returns 2 (H_MSG_TRUE) if all parameters are correct. If necessary, an exception is raised.

Possible Predecessors

gen_contour_region_xldgen_contour_region_xldGenContourRegionXldGenContourRegionXldGenContourRegionXld, zero_crossing_sub_pixzero_crossing_sub_pixZeroCrossingSubPixZeroCrossingSubPixZeroCrossingSubPix, threshold_sub_pixthreshold_sub_pixThresholdSubPixThresholdSubPixThresholdSubPix

Alternatives

intersectionintersectionIntersectionIntersectionIntersection

See also

difference_closed_contours_xlddifference_closed_contours_xldDifferenceClosedContoursXldDifferenceClosedContoursXldDifferenceClosedContoursXld, symm_difference_closed_contours_xldsymm_difference_closed_contours_xldSymmDifferenceClosedContoursXldSymmDifferenceClosedContoursXldSymmDifferenceClosedContoursXld, union2_closed_contours_xldunion2_closed_contours_xldUnion2ClosedContoursXldUnion2ClosedContoursXldUnion2ClosedContoursXld, intersection_closed_polygons_xldintersection_closed_polygons_xldIntersectionClosedPolygonsXldIntersectionClosedPolygonsXldIntersectionClosedPolygonsXld

Module

Foundation


ClassesClasses | | Operators