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>.