The probability mass function of regular difference (PMFRD) represents the 
  probabilities of a random variable W, being $W=(i-j)$. 
 
  $Pr(w+256)=P((i-j)=w)$, $-255 \leq w \leq 255$

  Where i is one intensity id line in COM matrix and j is one intensity id 
  column in COM. Thus  $Pr(w+256)=P((i-j)=w)$ is the probability of happen an 
  intensity jump of value i to value $j=i+w$, with -255<=w<=255. This function 
  calculates a similar difference probability proposed in [1]. The COM matrix 
  need have 256x256 elements.

  References:
  [1]  R.M. Haralick, K. Shanmugam, and Its' Hak Dinstein. 'Textural Features 
       for Image Classification'. In: Systems, Man and Cybernetics, IEEE 
       Transactions on SMC-3.6 (Nov. 1973), pages 610-621. ISSN: 0018-9472. 

  After starting the main routine just type the following command at the
  prompt:
  Pr = pmfrd(COM);
  
  Input:
  COM  is the Co-Occurrence matrix. A 2D matrix with 256 lines and 256 columns.

  Output:
  Pr   is the probability mass function, where  $Pr(w+256)=P((i-j)=w)$ is the 
       probability of happen an intensity jump of value i to value j=i+w, with 
       -255<=w<=255. Pr is a vector with 511 elements.
  W    [OPTIONAL] is a vector with the intensities jumps $(i-j)=w$.
       W=[-255:255];


  For help, bug reports and feature suggestions, please visit:
  http://nongnu.org/bsltl/

Package: bsltl