getMiddleMatrix

Extract values near middle of a matrix.

   middleM = getMiddleMatrix(m,sz)

 Data values from the middle of a matrix are returned. The total number
 of extracted pixels is 1 + round(sz/2)*2.  This is awkward  for small
 numbers of sz, but OK for bigger numbers.  
   
  Example:
     m = reshape([1:81],9,9);
     foo = getMiddleMatrix(m,3)

 Copyright ImagEval Consultants, LLC, 2003.