    - n dimensional array to standardize
  flag    - [1] determines normalization procedure. Sets X to:
            1: have zero mean and unit variance
            2: range in [0,1]
            3: have zero mean 
            4: have zero mean and unit magnitude
            5: zero mean/unit variance, throws out extreme values 
               and also normalizes to [0,1]

 OUTPUTS
  X       - X after normalization.

 EXAMPLE
  I = double(imread('cameraman.tif'));
  N = imNormalize(I,1);
  [mean(I(:)), std(I(