1pfsstat(1)                  General Commands Manual                 pfsstat(1)
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NAME

6       pfsstat - Show frame / image statistics
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SYNOPSIS

9       pfsstat
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DESCRIPTION

12       This  command will show a short text statistic on each image in the pfs
13       stream. In the statistics you can find:
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15       File - name of the input file
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17       Width, Height - image dimensions
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19       Minimum - minimum luminance of an image(*), given in linear
20              units (relative luminance in cd/m^2) and logarithmic units
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22       Maximum - maximum luminance of an image(*)
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24       Average - average luminance of an image(*)
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26       Mean - mean luminance of an image(*)
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28       (*) Before min, max, average, median and dynamic range is computed, the
29       following  processing  is  performed  on an image: 1) negative and zero
30       values are replaced with the smallest positive value (to compute  loga‐
31       rithms);  2)  the  image  is  low-pass filtered. The low-pass filtering
32       removes few very dark or very  bright  pixels  that  can  significantly
33       influence estimation of the dynamic range. The percentile, instead of a
34       low-pass filter, is sometimes used for the  same  purpose.  However,  a
35       low-pass  filter is preferred to the percentile in pfstools since, tak‐
36       ing into account the processing that is happening in the  human  visual
37       system, low-frequency band filter is more plausible.
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39       Note: This command requires GNU Octave.
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EXAMPLES

42       pfsin memorial.hdr | pfsstat
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44       Show statistics for the memorial image.
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BUGS

47       Please   report  bugs  and  comments  to  Rafal  Mantiuk  <mantiuk@mpi-
48       sb.mpg.de>.
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54                                                                    pfsstat(1)
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