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)