This function implements the Absolute Value of the Differences (AVD) method [1], 
  only using a pixel-by time, with the normalization of the co-occurrence matrix (COM) 
  proposed by CARDOSO, R.R. et al. [2]. 
  Use as input data a 3D matrix created grouping NTIMES intensity matrices I(k)
  1<=k<=NTIMES

  I(k)=DATA(:,:,k)

  $GAVD=\frac{1}{NTIMES-1}\sum\limits_{k=1}^{NTIMES-1} |I(k)-I(k+1)| \approx E[|I(k)-I(k+1)|]$


  References:
  [1]  BRAGA, R.A. et al. Evaluation of activity through dynamic laser speckle 
       using the absolute value of the differences, Optics Communications, v. 284, 
       n. 2, p. 646-650, 2011.
  [2]  R.R. Cardoso, R.A. Braga, Enhancement of the robustness on dynamic speckle 
       laser numerical analysis, Optics and Lasers in Engineering, 
       Volume 63, December 2014, Pages 19-24, ISSN 0143-8166, 
       http://dx.doi.org/10.1016/j.optlaseng.2014.06.004.


  After starting the main routine just type the following command at the
  prompt:
  GAVD = graphavd(DATA);
    
  Input:
  DATA is the speckle data pack. Where DATA is a 3D matrix created grouping NTIMES 
       intensity matrices with NLIN lines and NCOL columns. When N=size(DATA), then
       N(1,1) represents NLIN and
       N(1,2) represents NCOL and
       N(1,3) represents NTIMES.
  SHOW [Optional] If SHOW is equal to string 'off', then do not plot the result.

  Output:
  GAVD returns the GAVD matrix.


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

Package: bsltl