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

56       You must specify exactly one of -sum, -mean, -min, or -max.
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60       -sum
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62              This option makes the summary function addition.
63                   In each column and plane of  the  output  row,  the  sample
64              value is the
65                   sum  of all the samples values in the same column and plane
66              of the input.
67                   If a result is greater than the image maxval, it is clipped
68              to
69                   the maxval.
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72       -mean
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74              This option makes the summary function arithmetic mean.
75                   In  each  column  and  plane  of the output row, the sample
76              value is the
77                   mean of all the samples values in the same column and plane
78              of the input.
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81       -min
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83              This option makes the summary function arithmetic minimum.
84                   In  each  column  and  plane  of the output row, the sample
85              value is the
86                   minimum of all the samples values in the  same  column  and
87              plane of
88                   the input.
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91       -max
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93              This option makes the summary function arithmetic maximum.
94                   In  each  column  and  plane  of the output row, the sample
95              value is
96                   the maximum of all the samples values in  the  same  column
97              and
98                   plane of the input.
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SEE ALSO

104       pamsumm(1), pamscale(1), pamfunc(1), pamarith(1), pamscale(1), pam(1),
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HISTORY

108       pamsummcol was added to Netpbm in Release 10.21 (March 2004).
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112netpbm documentation            25 January 2009      Pamsummcol User Manual(0)
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