Name
openingopeningOpeningOpening — Open a region.
An openingopeningOpeningOpeningOpening operation is defined as an erosion followed
by a Minkowsi addition. By applying openingopeningOpeningOpeningOpening to a
region, larger structures remain mostly intact, while small
structures like lines or points are eliminated. In contrast, a
closingclosingClosingClosingClosing operation results in small gaps being retained
or filled up (see closingclosingClosingClosingClosing).
openingopeningOpeningOpeningOpening serves to eliminate small regions (smaller than
StructElementStructElementStructElementStructElementstructElement) and to smooth the boundaries of a region.
The position of StructElementStructElementStructElementStructElementstructElement is meaningless, since an
opening operation is invariant with respect to the choice of the
reference point.
Structuring elements (StructElementStructElementStructElementStructElementstructElement) can be generated
with operators such as gen_circlegen_circleGenCircleGenCircleGenCircle, gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1,
gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2, gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse,
draw_regiondraw_regionDrawRegionDrawRegionDrawRegion, gen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygonGenRegionPolygon,
gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints, etc.
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on tuple level.
Structuring element (position-invariant).
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
/* simulation of opening */
my_opening(Hobject In, Hobject StructElement, Hobject *Out)
{
Hobject H;
erosion1(In,StructElement,&H,1);
minkowski_add1(H,StructElement,Out,1);
clear_obj(H);
}
/* Large regions in an aerial picture (beech trees or meadows): */
read_image(&Image,"forest_road");
threshold(Image,&Light,160.0,255.0);
gen_circle(&StructElement,100.0,100.0,10.0);
/* selecting the large regions */
opening(Light,StructElement,&Large);
/* Selecting of edges with certain orientation: */
read_image(&Image,"fabrik");
sobel_amp(Image,&Sobel,"sum_abs",3);
threshold(Sobel,Edges,30.0,255.0);
gen_rectangle2(&StructElement,100.0,100.0,3.07819,20.0,1.0);
opening(Edges,StructElement,&Direction);
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
* Large regions in an aerial picture (beech trees or meadows):
read_image(Image,'forest_road')
threshold(Image,Light,160,255)
gen_circle(StructElement,100,100,10)
* selecting the large regions
opening(Light,StructElement,Large)
* Selecting of edges with certain orientation:
read_image(Image,'fabrik')
sobel_amp(Image,Sobel,'sum_abs',3)
threshold(Sobel,Edges,10,255)
gen_rectangle2(StructElement,100,100,3.07819,20,1)
opening(Edges,StructElement,Direction)
Let F1 be the area of the input region, and F2 be the area of
the structuring element. Then the runtime complexity for one region
is:
openingopeningOpeningOpeningOpening returns 2 (H_MSG_TRUE) if all parameters are correct.
The behavior in case of empty or no input region can be set via:
-
no region:
set_system('no_object_result',<RegionResult>)
-
empty region:
set_system('empty_region_result',<RegionResult>)
Otherwise, an exception is raised.
thresholdthresholdThresholdThresholdThreshold,
regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowing,
connectionconnectionConnectionConnectionConnection,
union1union1Union1Union1Union1,
watershedswatershedsWatershedsWatershedsWatersheds,
class_ndim_normclass_ndim_normClassNdimNormClassNdimNormClassNdimNorm,
gen_circlegen_circleGenCircleGenCircleGenCircle,
gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse,
gen_rectangle1gen_rectangle1GenRectangle1GenRectangle1GenRectangle1,
gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2,
draw_regiondraw_regionDrawRegionDrawRegionDrawRegion,
gen_region_pointsgen_region_pointsGenRegionPointsGenRegionPointsGenRegionPoints,
gen_region_polygon_filledgen_region_polygon_filledGenRegionPolygonFilledGenRegionPolygonFilledGenRegionPolygonFilled
reduce_domainreduce_domainReduceDomainReduceDomainReduceDomain,
select_shapeselect_shapeSelectShapeSelectShapeSelectShape,
area_centerarea_centerAreaCenterAreaCenterAreaCenter,
connectionconnectionConnectionConnectionConnection
minkowski_add1minkowski_add1MinkowskiAdd1MinkowskiAdd1MinkowskiAdd1,
erosion1erosion1Erosion1Erosion1Erosion1,
opening_circleopening_circleOpeningCircleOpeningCircleOpeningCircle
gen_circlegen_circleGenCircleGenCircleGenCircle,
gen_rectangle2gen_rectangle2GenRectangle2GenRectangle2GenRectangle2,
gen_region_polygongen_region_polygonGenRegionPolygonGenRegionPolygonGenRegionPolygon
Foundation