1pfsstat(1)                  General Commands Manual                 pfsstat(1)
2
3
4

NAME

6       pfsstat - Show frame / image statistics
7

SYNOPSIS

9       pfsstat
10

DESCRIPTION

12       This  command will show a short text statistic on each image in the pfs
13       stream. In the statistics you can find:
14
15       File - name of the input file
16
17       Width, Height - image dimensions
18
19       Minimum - minimum luminance of an image(*), given in linear
20              units (relative luminance in cd/m^2) and logarithmic units
21
22       Maximum - maximum luminance of an image(*)
23
24       Average - average luminance of an image(*)
25
26       Mean - mean luminance of an image(*)
27
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.
38
39       Note: This command requires GNU Octave.
40

EXAMPLES

42       pfsin memorial.hdr | pfsstat
43
44       Show statistics for the memorial image.
45

BUGS

47       Please   report  bugs  and  comments  to  Rafal  Mantiuk  <mantiuk@mpi-
48       sb.mpg.de>.
49
50
51
52
53
54                                                                    pfsstat(1)