Regular Value of the Differences (RVD) method [1]. This function implements the
  modification proposed by  over the AVD [2].
  This method can be combined with:

  $Y \approx E[(i-j)]$
  $Y2\approx E[(i-j)^2]$
  $Y3\approx E[(i-j)^2] -E[(i-j)]^2$

  TYPE 1: The normalized co-occurrence matrix (COM) proposed by 
          CARDOSO, R.R. et al. [2]. The RVD first moment: $Y$.
  TYPE 2: The CARDOSO, R.R. et al. [2] COM normalization with quadratic RVD  
          The RVD second moment: $Y2$.
  TYPE 3: The RVD center second moment: $Y3$.
  TYPE 4: The normalized co-occurrence matrix (COM) proposed by 
          ARIZAGA, R. et al. [3]: $Y4$.

  References:
  [1]  Pujaico Rivera Fernando. Paper coming soon.
  [2]  BRAGA R.A. CARDOSO, R.R. Enhancement of the robustness on dynamic speckle 
       laser numerical analysis. Optics and Lasers in Engineering, 
       63(Complete):19-24, 2014.
  [3]  ARIZAGA, R. et al. Speckle time evolution characterization by the 
       co-occurrence matrix analysis. Optics and Laser Technology, Amsterdam, 
       v. 31, n. 2, p. 163-169, 1999.

  After starting the main routine just type the following command at the
  prompt:
           [Y] = rvd(COM);
        [Y Y2] = rvd(COM,2);
  [Y Y2 Y3 Y4] = rvd(COM,2,3,4);
  [Y Y4 Y3 Y2] = rvd(COM,4,3,2);

  Input:
  COM  is a 2D matrix, with 256 lines and 256 columns, that represents the 
       Co-Occurrence Matrix of a THSP matrix. The element COM(a,b), in the 
       co-occurrence matrix, represents the quantity of times that, in two 
       successive columns of a THSP matrix, the intensity values jump of 
       a-1 to b-1.
  TYPE [Optional] the function returns an additional result in the same position.
       If TYPE is equal to 2, the function also returns the RVD second moment, using the 
       CARDOSO[2] COM normalization with ARIZAGA[3] value difference.
       If TYPE is equal to 3, the function also returns the RVD center second moment. 
       If TYPE is equal to 4, the function also returns the RVD with ARIZAGA[3] 
       COM normalization.

  Output:
  Y    is the value of RVD first moment [?].

  X    If TYPE is equal to 2, the function also returns the RVD second moment, using the 
       CARDOSO[2] COM normalization with ARIZAGA[3] value difference.
       If TYPE is equal to 3, the function also returns the RVD center second moment. 
       If TYPE is equal to 4, the function also returns the RVD with ARIZAGA[3] COM normalization.


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

Package: bsltl