DIPlib Documentation - ©1995-2010 Quantitative Imaging Group, Delft University of Technology.

GeneralisedKuwahara

Generalised Kuwahara filter

SYNOPSIS

#include "dip_filtering.h"

dip_Error dip_GeneralisedKuwahara ( in, selection, out, se, boundary, filterSize, shape, minimum )

DATA TYPES

binary, integer, float

FUNCTION

This function is a generalisation of the Kuwahara filter in the sense that is does not use the variance criterion to select the smoothed value, but instead accepts an image with the selection values. The algorithm finds, for every pixel, the minimum or maximum (as specified with minimum) value of selection within the filter window (its size specified by filterSize), and outputs the corresponding value in in. When in is the output of Uniform, and selection is the output of VarianceFilter, this function produces the same result as Kuwahara.

If shape is not equal to DIP_FLT_SHAPE_STRUCTURING_ELEMENT, se is allowed to be set to zero. When shape is set to DIP_FLT_SHAPE_STRUCTURING_ELEMENT, filterParam is ignored, (and can be set to zero).

ARGUMENTS

Data typeNameDescription
dip_ImageinInput
dip_ImageselectionSelection
dip_ImageoutOutput
dip_ImageseStructuring element
dip_BoundaryArrayboundaryBoundary conditions
dip_FloatArrayfilterSizeFilter sizes
dip_FilterShapeshapeFilter shape
dip_BooleanminimumSelect minimum or maximum?

The enumerator dip_FilterShape contains the following constants:

NameDescription
DIP_FLT_SHAPE_DEFAULTdefault structuring element, same as DIP_FLT_SHAPE_RECTANGULAR
DIP_FLT_SHAPE_RECTANGULARrectangular structuring element
DIP_FLT_SHAPE_ELLIPTICelliptic structuring element
DIP_FLT_SHAPE_DIAMONDdiamond shaped structuring element
DIP_FLT_SHAPE_PARABOLICparabolic structuring element
DIP_FLT_SHAPE_STRUCTURING_ELEMENTuse se as structuring element

NOTE

The filter shape DIP_FLT_SHAPE_PARABOLIC, as well as custom grey-value shapes, are not supported.

SEE ALSO

Kuwahara, KuwaharaImproved, GeneralisedKuwaharaImproved, VarianceFilter, Uniform