HALCON Reference Manual 10.0.2
Name
smallest_circlesmallest_circlesmallest_circleSmallestCircleSmallestCircle — Smallest surrounding circle of a region.
The operator smallest_circlesmallest_circlesmallest_circleSmallestCircleSmallestCircle determines the smallest
surrounding circle of a region, i.e., the circle with the smallest
area of all circles containing the region. For this circle the
center (RowRowRowRowrow,ColumnColumnColumnColumncolumn) and the radius
(RadiusRadiusRadiusRadiusradius) are calculated. The operator is applied when,
for example, the location and size of circular objects (e.g.,
coins) which, however, are not homogeneous inside or have broken
edges due to bad segmentation, has to be determined. The output of
the operator is selected in such a way that it can be used as input
for the operators disp_circledisp_circledisp_circleDispCircleDispCircle and
gen_circlegen_circlegen_circleGenCircleGenCircle.
If several regions are passed in RegionsRegionsRegionsRegionsregions corresponding
tuples are returned as output parameter. In case of empty region
all parameters have the value 0.0 if no other behavior was set (see
set_systemset_systemset_systemSetSystemSetSystem).
Internally, the calculation is based on the center coordinates of
the region pixels. To take into account that pixels are not just
infinitely small points but have a certain area, the calculated
radius is enlarged by 0.5 before it is returned in
RadiusRadiusRadiusRadiusradius. This, in most cases, gives acceptable results.
However, in the worst case (pixel diagonal) this enlargement is not
sufficient. If one wants to ensure that the border of the input
region completely lies within the circle, one had to enlarge the
radius by 1/sqrt(2) instead of 0.5. Consequently,
the value returned in RadiusRadiusRadiusRadiusradius must be corrected by
1/sqrt(2)-0.5. However, this would also be only
an upper bound, i.e., the circle with the corrected radius would be
slightly too big in most cases.
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Automatically parallelized on tuple level.
RowRowRowRowrow (output_control) circle.center.y(-array) → HTupleHTupleVARIANTHtuple (real) (double) (double) (double) (double)
Line index of the center.
Column index of the center.
Radius of the surrounding circle.
Assertion: Radius >= 0
read_image(Image,'fabrik')
open_window(0,0,-1,-1,'root','visible','',WindowHandle)
regiongrowing(Image,Seg,5,5,6,100)
select_shape(Seg,H,'area','and',100,2000)
smallest_circle(H,Row,Column,Radius)
gen_circle(Circles,Row,Column,Radius)
set_draw(WindowHandle,'margin')
disp_region(Circles,WindowHandle)
read_image(&Image,"fabrik");
open_window(0,0,-1,-1,0,"visible","",&WindowHandle);
regiongrowing(Image,&Seg,5,5,6.0,100);
select_shape(Seg,&H,"area","and",100.0,2000.0);
T_smallest_circle(H,&Row,&Column,&Radius);
T_gen_circle(&Circles,Row,Column,Radius);
set_draw(WindowHandle,"margin");
disp_region(Circles,WindowHandle);
#include "HIOStream.h"
#if !defined(USE_IOSTREAM_H)
using namespace std;
#endif
#include "HalconCpp.h"
using namespace Halcon;
int main (int argc, char *argv[])
{
Tuple row, col, rad;
HImage img (argv[1]);
HWindow w;
img.Display (w);
HRegionArray reg = img.Regiongrowing (5, 5, 6.0, 100);
HRegionArray seg = reg.SelectShape ("area", "and", 100.0, 1000.0);
row = seg.SmallestCircle (&col, &rad);
HRegionArray circ = HRegionArray::GenCircle (row, col, rad);
w.SetDraw ("margin");
w.SetColor ("green"); reg.Display (w);
w.SetColor ("blue"); seg.Display (w);
w.SetColor ("red"); circ.Display (w);
w.Click ();
return(0);
}
read_image(Image,'fabrik')
open_window(0,0,-1,-1,'root','visible','',WindowHandle)
regiongrowing(Image,Seg,5,5,6,100)
select_shape(Seg,H,'area','and',100,2000)
smallest_circle(H,Row,Column,Radius)
gen_circle(Circles,Row,Column,Radius)
set_draw(WindowHandle,'margin')
disp_region(Circles,WindowHandle)
read_image(Image,'fabrik')
open_window(0,0,-1,-1,'root','visible','',WindowHandle)
regiongrowing(Image,Seg,5,5,6,100)
select_shape(Seg,H,'area','and',100,2000)
smallest_circle(H,Row,Column,Radius)
gen_circle(Circles,Row,Column,Radius)
set_draw(WindowHandle,'margin')
disp_region(Circles,WindowHandle)
If F is the area of the region, then the mean runtime complexity
is O(sqrt(F).
The operator smallest_circlesmallest_circlesmallest_circleSmallestCircleSmallestCircle returns the value 2 (H_MSG_TRUE)
if the input is not empty. The behavior in case of empty input (no input regions available)
is set via the operator set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>).
The behavior in case of empty region (the region is the empty set) is set via
set_system('empty_region_result',<Result>)set_system("empty_region_result",<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>).
If necessary an exception is raised.
thresholdthresholdthresholdThresholdThreshold,
regiongrowingregiongrowingregiongrowingRegiongrowingRegiongrowing,
connectionconnectionconnectionConnectionConnection,
runlength_featuresrunlength_featuresrunlength_featuresRunlengthFeaturesRunlengthFeatures
gen_circlegen_circlegen_circleGenCircleGenCircle,
disp_circledisp_circledisp_circleDispCircleDispCircle
elliptic_axiselliptic_axiselliptic_axisEllipticAxisEllipticAxis,
smallest_rectangle1smallest_rectangle1smallest_rectangle1SmallestRectangle1SmallestRectangle1,
smallest_rectangle2smallest_rectangle2smallest_rectangle2SmallestRectangle2SmallestRectangle2
set_shapeset_shapeset_shapeSetShapeSetShape,
select_shapeselect_shapeselect_shapeSelectShapeSelectShape,
inner_circleinner_circleinner_circleInnerCircleInnerCircle
Foundation
| HALCON Reference Manual 10.0.2 |
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