filterBinomial1d

 1D binomial filter (approximation to Gaussian filter)

 Creates a binomial filter of size 2*r+1 x 1.  This can be used to
 approximate the Gaussian distribution with sigma=sqrt((2*r+1)/4). For
 large r, should give same output as:
  g = fspecial( 'Gaussian', [2*r+1,1],sqrt((2*r+1)/4) );
 Given sigma, use r ~= 2*sigma^2.

 Use F = f*f' to get the equivalent 2d filter.

 USAGE
  f = filterBinomial1d( r, [show] )

 INPUTS
  r       - mask will have length 2r+1 and var=(2*r+1)/4
  show    - [0] figure to use for optional display

 OUTPUTS
  f       - 1D binomial filter

 EXAMPLE
  r = 10;
  fbinom = filterBinomial1d( r, 1 );
  fgauss = filterGauss( 2*r+1, [], (2*r+1)/4, 2);

 See also FILTERGAUSS

 Piotr's Computer Vision Matlab Toolbox      Version 2.0
 Copyright 2014 Piotr Dollar.  [pdollar-at-gmail.com]
 Licensed under the Simplified BSD License [see external/bsd.txt]