1Pamsummcol User Manual(0)                            Pamsummcol User Manual(0)
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NAME

6       pamsummcol - summarize (sum, average, etc) a Netpbm image by column
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SYNOPSIS

10       pamsummcol { -sum | -mean | -min | -max } [imagefile]
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12       All  options  can  be abbreviated to their shortest unique prefix.  You
13       may use two hyphens instead of one.  You may separate  an  option  name
14       and its value with white space instead of an equals sign.
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DESCRIPTION

18       This program is part of Netpbm(1).
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20       pamsummcol  reads  a  Netpbm  image (PNM or PAM) and performs a summary
21       function over all the rows in each column (sum, mean, etc.).   It  pro‐
22       duces  an  image  of the same kind that the same width and depth as the
23       input, and one row high.  Its sample values are the result of the  sum‐
24       mary.
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26       pamsummcol performs the summary operation on each plane independently.
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28       pamsummcol  performs  the operation on the actual sample values, not on
29       the light intensities represented by them in the case that the image is
30       a PGM or PPM image.
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32       If  you  want  to  summarize by row instead of by column, run the input
33       through pamflip first (and if you want the output to be a single column
34       instead of a single row, use pamflip again).
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36       If  you  want  to  summarize over the entire image (getting a one-tuple
37       output image), use pamsumm to get a summary row, pamflip to  turn  that
38       into a column, the pamsumm again to summarize the column.
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40       If  you  want  to  summarize the individual samples in an entire image,
41       instead of by tuple, use pamsumm.
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43       pamsummcol performs the operation on the actual sample values,  not  on
44       the light intensities represented by them in the case that the image is
45       a PGM or PPM image or PAM equivalent.  You can use pnmgamma to  convert
46       such  an image to one with samples proportional to light intensity, and
47       then use pamsummcol on the result.
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49       You can achieve the same thing as pamsummcol -mean with pamscale.  Just
50       scale  vertically to a single row, without scaling horizontally at all.
51       Use the pixel mixing method.
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OPTIONS

55       In addition to the options common to all programs  based  on  libnetpbm
56       (most notably -quiet, see
57        Common Options ⟨index.html#commonoptions⟩ ), pamsummcol recognizes the
58       following command line options:
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60       You must specify exactly one of -sum, -mean, -min, or -max.
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64       -sum
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66              This option makes the summary function addition.
67                   In each column and plane of  the  output  row,  the  sample
68              value is the
69                   sum  of all the samples values in the same column and plane
70              of the input.
71                   If a result is greater than the image maxval, it is clipped
72              to
73                   the maxval.
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76       -mean
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78              This option makes the summary function arithmetic mean.
79                   In  each  column  and  plane  of the output row, the sample
80              value is the
81                   mean of all the samples values in the same column and plane
82              of the input.
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85       -min
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87              This option makes the summary function arithmetic minimum.
88                   In  each  column  and  plane  of the output row, the sample
89              value is the
90                   minimum of all the samples values in the  same  column  and
91              plane of
92                   the input.
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95       -max
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97              This option makes the summary function arithmetic maximum.
98                   In  each  column  and  plane  of the output row, the sample
99              value is
100                   the maximum of all the samples values in  the  same  column
101              and
102                   plane of the input.
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SEE ALSO

108       pamsumm(1), pamflip(1), pamfunc(1), pamarith(1), pamscale(1), pam(1),
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HISTORY

112       pamsummcol was added to Netpbm in Release 10.21 (March 2004).
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DOCUMENT SOURCE

115       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
116       source.  The master documentation is at
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118              http://netpbm.sourceforge.net/doc/pamsummcol.html
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120netpbm documentation            25 January 2009      Pamsummcol User Manual(0)
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