fuzzy_entropy

Herror ::fuzzy_entropy ( Hobject Regions, Hobject Image, const HTuple &Apar, const HTuple &Cpar, double *Entropy ) Herror ::fuzzy_entropy ( Hobject Regions, Hobject Image, const HTuple &Apar, const HTuple &Cpar, HTuple *Entropy ) double HRegion::FuzzyEntropy ( const HImage &Image, const HTuple &Apar, const HTuple &Cpar ) const HTuple HRegionArray::FuzzyEntropy ( const HImage &Image, const HTuple &Apar, const HTuple &Cpar ) const

Determine the fuzzy entropy of regions.

::fuzzy_entropy calculates the fuzzy entropy of a fuzzy set. To do so, the image is regarded as a fuzzy set. The entropy then is a measure of how well the image approximates a white or black image. It is defined as follows:

                   
             1     ----
  h(x) = --------- \    T (l) h(l)
         M N ln(2) /     e
		     ----

where MxN is the size of the image, and h(l) is the histogram of the image. Furthermore,

  T (l) = -u(l) ln(u(l)) - (1-u(l)) ln(1-u(l))
   e

Here, u(x(m,n)) is a fuzzy membership function defining the fuzzy set (see ::fuzzy_perimeter). The same restrictions hold as in ::fuzzy_perimeter.

Parameters

`Regions` (input_object)	region(-array) `->` Hobject: HRegion(Array)
Regions for which the fuzzy entropy is to be calculated.

`Image` (input_object)	image `->` Hobject: HImage ( byte )
Input image containing the fuzzy membership values.

`Apar` (input_control)	integer `->` HTuple.long
Start of the fuzzy function.
Default value: 0
Suggested values: 0, 5, 10, 20, 50, 100
Typical range of values: `0 <= Apar <= 255` (lin)
Minimum increment: 1
Recommended increment: 5

`Cpar` (input_control)	integer `->` HTuple.long
End of the fuzzy function.
Default value: 255
Suggested values: 50, 100, 150, 200, 220, 255
Typical range of values: `0 <= Cpar <= 255` (lin)
Minimum increment: 1
Recommended increment: 5
Restriction: `Apar <= Cpar`

`Entropy` (output_control)	real(-array) `->` (HTuple.) double *
Fuzzy entropy of a region.

Example

/* To find a Fuzzy Entropy from an Image */
read_image(&Image,'affe') ;
fuzzy_entropy(Trans,Trans,0,255,&Entro) ;

Result

The operator ::fuzzy_entropy returns the value H_MSG_TRUE if the parameters are correct. Otherwise an exception is raised.

See also

::fuzzy_perimeter

References

M.K. Kundu, S.K. Pal: `Äutomatic selection of object enhancement operator with quantitative justification based on fuzzy set theoretic measures''; Pattern Recognition Letters 11; 1990; pp. 811-829.

Module

Image filters