bottom_hat ( Region, StructElement : RegionBottomHat : : )

Compute the bottom hat of regions.

bottom_hat computes the closing of Region with StructElement. The difference between the result of the closing and the original region is called the bottom hat. In contrast to closing, which merges regions under certain circumstances, bottom_hat computes the regions generated by such a merge.

The position of StructElement is meaningless, since a closing operation is invariant with respect to the choice of the reference point.

Structuring elements (StructElement) can be generated with operators such as circle, rectangle1, rectangle2, ellipse, draw_region, store_polygon, store_coord, etc.


Parameters

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

StructElement (input_object)
region -> object
Structuring element (position independent).

RegionBottomHat (output_object)
region(-array) -> object
Result of the bottom hat operator.


Example
read_image ( : Image : '/bilder/name.ext' : ) >
threshold__ ( Image : Regions : 128 : 255 : ) >
circle ( : Circle : 0, 0, 16 : ) >
bottom_hat ( Regions, Circle : RegionBottomHat :: ).

Result

bottom_hat returns TRUE if all parameters are correct. The behavior in case of empty or no input region can be set via:

  a) no region:    set_system(::'no_object_result',<RegionResult>:)
  b) empty region: set_system(::'empty_region_result',<RegionResult>:)
Otherwise, an exception is raised.


Possible Predecessors

threshold__, regiongrowing__, connection, union1, watersheds, class_ndim1__, circle, ellipse, rectangle1, rectangle2, draw_region, store_coord, struct_elements, store_filled_polygon


Possible Successors

reduce_domain, select_shape, area_center, connection


Alternatives

closing, difference


See also

top_hat, morph_hat, grey_bothat, opening



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