This function creates a data pack (3D matrix) from a set of images in a directory. 
  All images should have the same number of lines and columns, and similar format.

  After starting the main routine just type the following command at the
  prompt:
  DATA = datapack(IMGDIR,IMGNAME,IMGN1,IMGN2,IMGFMT);

  %% To filenames: 'seed1.bmp', 'seed2,bmp', ..., 'seed128.bmp'
  DATA = datapack('/user/images/sample1','seed',1,128,'bmp');

  %% To filenames: 'img1coffee.bmp', 'img2coffee,bmp', ..., 'img100coffee.bmp'
  DATA = datapack('/user/images/sample1','img%dcoffee',1,100,'bmp');

  %% To filenames: 'img0001.bmp', 'img0002,bmp', ..., 'img0123.bmp'
  DATA = datapack('/user/images/sample1','img%04d',1,123,'bmp');

  Input:
  IMGDIR  is a directory path where the images are, with format names as
          NAME=[IMGNAME,'.',IMGFMT].
  IMGNAME is the format filename, example: if the files in IMGDIR have names as 
          'fig1.bmp', then IMGNAME='fig' or IMGNAME='fig%d'. If IMGNAME not
          contain a format specifiers of family %d, them this format specifiers 
          is added at the final of IMGNAME string. The format string is similar
          to the function printf of others programming languages.
          Only are permitted format specifiers of family %d, given that will
          be replaced a decimal number.
  IMGN1   is the index of the first image, example: if the files have names from 
          'fig1.bmp' until 'fig4.bmp', then IMGN1=1.
  IMGN2   is the index of the last image, example: if the files have names from 
          'fig1.bmp' until 'fig4.bmp', then IMGN2=4.
  IMGFMT  is the filetype of the image files, example: if the files have names 
          as 'fig1.bmp', then IMGFMT='bmp'. Current is only permitted IMGFMT='bmp'.
  LPOS    [Optional] This value is optional. It is the first line position for a window
          analysis.
  CPOS    [Optional] This value is optional. It is the first column position for a window
          analysis.
  NLIN    [Optional] This value is optional. It is the number of lines of a window under analysis.
  NCOL    [Optional] This value is optional. It is the number of columns of a window under analysis.

  Output:
  DATA    is the speckle data. Where DATA is a 3D matrix created grouping NTIMES=IMGN2-IMGN1+1
          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.


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

Package: bsltl