opening_golay — Open a region with an element from the Golay alphabet.
opening_golay is defined as a Minkowski subtraction followed by a Minkowski addition. First the Minkowski subtraction of the input region (Region) with the structuring element from the Golay alphabet defined by GolayElement and Rotation is computed. Then the Minkowski addition of the result and the structuring element rotated by 180 degrees is performed.
The following structuring elements are available:
'l', 'm', 'd', 'c', 'e', 'i', 'f', 'f2', 'h', 'k'.
The rotation number Rotation determines which rotation of the element should be used, and whether the foreground (even) or background version (odd) of the selected element should be used. The Golay elements, together with all possible rotations, are described with the operator golay_elements.
opening_golay serves to eliminate regions smaller than the structuring element, and to smooth regions' boundaries.
Not all values of Rotation are valid for any Golay element. For some of the values of Rotation, the resulting regions are identical to the input regions.
Regions to be opened.
Structuring element from the Golay alphabet.
Default value: 'h'
List of values: 'c', 'd', 'e', 'f', 'f2', 'h', 'i', 'k', 'l', 'm'
Rotation of the Golay element. Depending on the element, not all rotations are valid.
Default value: 0
List of values: 0, 2, 4, 6, 8, 10, 12, 14, 1, 3, 5, 7, 9, 11, 13, 15
Let F be the area of an input region. Then the runtime complexity for one region is:
O(6 * sqrt(F)) .
opening_golay 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.
threshold, regiongrowing, connection, union1, watersheds, class_ndim_norm
reduce_domain, select_shape, area_center, connection
erosion_golay, dilation_golay, closing_golay, hit_or_miss_golay, thinning_golay, thickening_golay, golay_elements