pfsview(1)

1pfsview(1)                  General Commands Manual                 pfsview(1)
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NAME

6       pfsview - Viewer for high-dynamic range images in pfs format
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SYNOPSIS

9       pfsview [--window_min <log_lum>] [--window_max <log_lum>]
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DESCRIPTION

12       pfsview  is  a QT application for viewing high-dynamic range images. It
13       expects pfs stream on the standard input and  displays  the  frames  in
14       that stream one by one.
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16       pfsv  script can be more convienent to use if hdr images are to be dis‐
17       played without any prior processing.
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DYNAMIC RANGE WINDOW

21       To show high-dynamic range data on a low-dynamic range monitor, pfsview
22       uses concept of a dynamic range window. The dynamic range window is the
23       highest and lowest value that should  be  mapped  to  black  and  white
24       pixel. Values above or below the window are clipped (see clipping meth‐
25       ods below). The dynamic range window is displayed in pfsview as a  blue
26       area on the dynamic range scale (second toolbox from the top). The win‐
27       dow can be moved, shrunk and expended using a mouse or a keyboard.
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CLIPPING METHODS

31       Currently, two clipping methods are available (see View menu):
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34       Simple clipping
35              The values above and below the dynamic  range  window  are  dis‐
36              played as black or white.
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39       Color-coded clipping
40              The  values above the dynamic range window are displayed as yel‐
41              low and below the window as green. This is helpful to see  which
42              parts of the image do not fit into the selected dynamic range.
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45       Keep brightness and hue
46              This method tries to preserve brightness and hue while sacrific‐
47              ing color saturation when the colors exceed the RGB color gamut.
48              Colors  are  desaturated in the RGB color space towards the neu‐
49              tral color (D65) of the corresponding luminance.
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MAPPING METHODS

53       High-dynamic range data are usually better visualized using  non-linear
54       scale,  for  example  a logarithmic or a power function. pfsview offers
55       several such scales, shown in View menu.  Gray-scale  values  for  each
56       mapping method are computed by the formulas:
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58       LINEAR: y = (x-min)/(max-min)
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60       GAMMA: y = [ (x-min)/(max-min) ]^gamma
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62       LOGARITHMIC: y = (log10(x)-log10(min))/(log10(max)-log10(min))
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64       where y is the gray-scale value after mapping, x is an input HDR value,
65       min and max are lower and upper bounds of the dynamic range window.
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OPTIONS

70       --window_min <log_lum>
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72              Lower bound of the values that should be  displayed  or  minimum
73              value  of the dynamic range window. The value should be given in
74              log_10 units, for example -1 if the lower bound  should  be  0.1
75              (10^-1).
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78       --window_max <log_lum>
79              Upper  bound  of  the values that should be displayed or minimum
80              value of the dynamic range window. The value should be given  in
81              log_10  units,  for  example -1 if the upper bound should be 0.1
82              (10^-1).
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EXAMPLES

86       pfsin memorial.hdr | pfsview
87              See the memorial image.
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90       pfsv memorial.hdr
91              The same as above, but using the utility script 'pv'.
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BUGS

98       Zomming in may sometimes show artifacts.
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100       Please  report  bugs  and  comments  to  Rafal  Mantiuk   <mantiuk@mpi-
101       sb.mpg.de>.
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