21 January 2014 HDR-VDP 2.2.1
   * Fixed issue when "Q" varied with image size. Q is now scaled 
     differently: 100 for the best quality and gets lower.
   * Q_MOS has been removed as unreliable. Use "Q instead. Note that the 
     relation between Q and MOS is not specified for now.
   * Some memory optimizations

19 October 2014 HDR-VDP 2.2.0

   * Improved quality predictions (pooling function optimized for HDR quality data set).
   * matlabPyrTools bundled with HDR-VDP-2 for easier installation
   * New improved hdrvdp_visualize.m
   * Surround luminance (surround_l) is set to very low luminance (1e-5) by default
   * Added check for very low physical values to avoid a common misuse for color encodings
   * Minor performance improvement (caching)

21 January 2013 HDR-VDP 2.1.3

   * Updated documentation
   * Better compatibility with earlier versions of matlab
   * Better handling of surround_l - if computed automatically, it is kept 
     the same for both reference and test images. This avoids false detection
     at the image boarder.

27 October 2011 HDR-VDP 2.1.2

   * Updated "epsilon" values that prevent NaN due to log of 0, but
     also cause Q_MOS to be relatively low for two identical images

30 August 2011 HDR-VDP 2.1.1

   * Fixed CSF formula in the code to be consistent with the
     paper. The CSF fitting parameters were updated as well.

17 June 2011  HDR-VDP 2.1

   * Extened model: CSF measured at 0.002 cd/m^2
   * New fit: fit to the new CSF measurements
   * New measurements: csfla dataset
   * New measurements: complexfest dataset
   * Bug fixed: nCSF did not change below 1 cd/m^2

28 April 2011  HDR-VDP 2.0

   This is the initial release, included with the supplementary
   materials of the SIGGRAPH'11 paper.