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EntropyFilter

EntropyFilter[image, r]
filters image by replacing every value by the information entropy of the values in its range r neighborhood.
EntropyFilter[data, r]
applies entropy filtering to an array of data.
  • EntropyFilter[image, r] computes the information entropy of the values in (2r+1)×(2r+1) blocks centered on each pixel.
  • Given a set of values pi, the information entropy is taken to be -sump_i log(p_i).
  • At the edges of an image, EntropyFilter uses smaller neighborhoods.
  • EntropyFilter[image, {r1, r2}] uses neighborhoods with vertical range r1 and horizontal range r2.
  • In EntropyFilter[data, ...], data can be an array of any rank, and can contain symbolic as well as numerical entries.
EXAMPLESCLOSE ALL
Basic Examples   (3)
Entropy filtering of random disks:
Apply entropy filtering to show areas of higher information content with higher intensities:
Apply an entropy filter to a vector of numbers:
Entropy filtering of random disks:
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Apply entropy filtering to show areas of higher information content with higher intensities:
In[1]:=
Click for copyable input
Out[1]=
 
Apply an entropy filter to a vector of numbers:
In[1]:=
Click for copyable input
Out[1]=
Applications   (1)
Entropy filtering can reveal JPEG compression artefacts:
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