inner_circle ( Regions : : : Row, Column, Radius )

Largest inner circle of a region.

The operator inner_circle determines the largest inner circle of a region, i.e. the circle with the largest area of all circles that fit into the region. For this circle the center (Row,Column) and the radius (Radius) are calculated. The output of the procedure is chosen in such a way that it can be used as input for the HORUS procedures disp_circle and circle. If several regions are passed in Regions corresponding tuples are returned as output parameters. In case of empty region all parameters have the value 0.0 if no other behavior was set (see set_system).


Attention

If several inner circles are present at a region only one solution is returned.


Parameters

Regions (input_object)
region(-array) -> object
Regions to be examined.

Row (output_control)
circle.center.y(-array) -> real
Line index of the center.

Column (output_control)
circle.center.x(-array) -> real
Column index of the center.

Radius (output_control)
circle.radius(-array) -> real
Radius of the inner circle.
Assertion: Radius >= 0


Example
read_image(:Image:'fabrik':) >
open_window(::0,0,-1,-1,'root','visible','':) >
regiongrowing__(Image:Seg:5,5,6,100:) >
select_shape(Seg:H:'area','and',100,2000:) >
inner_circle(H:::Row,Column,Radius) >
circle(:Circles:Row,Column,Radius:) >
set_draw(::'margin':) >
disp_region(Circles:::).

Complexity

If F is the area of the region and R is the radius of the inner circle the runtime complexity is O(F * R).


Result

The operator inner_circle returns the value 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>:), the behavior in case of empty region is set via set_system(::'empty_region_result',<Result>:). If necessary an exception is raised.


Possible Predecessors

threshold__, regiongrowing__, connection, fetch_chord


Possible Successors

circle, disp_circle


Alternatives

erosion_circle


See also

set_shape, select_shape, smallest_circle



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