Entropy of image | Matlab DSP

Technical discussion about Matlab and issues related to Digital Signal Processing.

Hi all, In the calculation of the entropy of an image, ENTROPY = - SIGMA(p log p ) j j 2 j how can we define the parameter 'probability' for an image? Regards, Prateek.

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You can use instead of probability, the counting of each pixel, I mean, what you need is calculate the histogram of the image. Take a look in the code below where S is the histogram.

N=sum(sum(S));

if ((N>0) & (min(S(:))>=0))
   Snz=nonzeros(S);
   H=log2(N)-sum(Snz.*log2(Snz))/N;
else
   H=0;
endPrateek Shrivastava <p...@indiatimes.com> wrote:

Hi all,

In the calculation of the entropy of an image,
ENTROPY = - SIGMA(p log p )
j j 2 j
how can we define the parameter 'probability' for an image?

Regards,

Prateek.

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Aurio Gon�alez Ten�rio
M. Sc. Student
Department of Communications - Decom
Faculty of Electrical and Computer Engineering - FEEC
State University of Campinas - UNICAMP, SP - Brazil
a...@decom.fee.unicamp.br

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Discussion Groups | Matlab DSP | Entropy of image

Entropy of image - Prateek Shrivastava - Jun 18 18:26:00 2003

Re: Entropy of image - Aurio G. Ten�rio - Jun 22 12:59:00 2003