NAME

       pfstmo_fattal02 - Gradient domain high dynamic range compression

SYNOPSIS

       pfstmo_fattal02 [--alpha <val>] [--beta <val>] [--saturation <val>] [--noise <val>] [--verbose] [--help]

DESCRIPTION

       This command implements a tone mapping operator as described in:

       Gradient  Domain  High  Dynamic  Range  Compression  R.  Fattal,  D.  Lischinski,  and  M.  Werman In ACM
       Transactions on Graphics, 2002.

       With respect to the  original  paper,  this  program  provides  additional  parameter  which  limits  the
       amplification  of  noise.  The noise is often starkly amplified because of division by zero in one of the
       equations in the paper. Extension contributed by Przemyslaw Bazarnik.

       Results of this TMO can be improved by using a gamma correction.

OPTIONS

       --alpha <val>, -a <val>

              Set alpha parameter. <val> defines the threshold gradient value (luminance differents of  adjacent
              pixels) below which the gradients are amplified (detail enhancement) and above which the gradients
              are attenuated (global contrast reduction).
               Suggested range is 1 to 0.0001. It is reasonable to change parameters by orders of magnitude,  so
              for instance trying 0.1, 0.01, 0.001 etc.  (see paper for details).

       --beta <val>, -b <val>

              Set  beta parameter. <val> sets the strength of gradient (local contrast) modification.  Suggested
              range is 0.8 to 0.96 (see paper for details).  Value of 1 does not change contrasts, values  above
              1  reverse  the effect: global contrast is stretched and details are attenuated.  Values below 0.5
              lead to very strong amplification of small contrast, so consider using --noise parameter close  to
              'alpha' value to prevent noise.

       --saturation <val>, -s <val>

              Amount of color saturation. Suggested range is 0.4 to 0.8. Default value: 0.6.

       --noise <val>, -n <val>

              Reduces  gradient  amplification  value  for gradients close to 0 and reduces noise in the result.
              <val> defines gradient value (luminance differents of adjacent pixels) which is treated as  noise.
              Suggested  range  is  0.0  to  the  value  of  alpha.  Default  value  calculated  based on alpha:
              0.001*alpha.

       --verbose

              Print additional information during program execution.

       --help

              Print list of command line options.

EXAMPLES

       pfsin memorial.hdr | pfstmo_fattal02 -v | pfsgamma -g 2.2 | pfsout memorial.png

              Tone map image and save it in png format.

SEE ALSO

       pfsin(1) pfsout(1) pfsview(1)

BUGS

       Please report bugs and comments on implementation to Grzegorz Krawczyk <krawczyk@mpi-sb.mpg.de>.

                                                                                              pfstmo_fattal02(1)