Pamsummcol User Manual(1) General Commands Manual Pamsummcol User Manual(1)
NAME
pamsummcol - summarize (sum, average, etc) a Netpbm image by column
SYNOPSIS
pamsummcol { -sum | -mean | -min | -max } [imagefile]
All options can be abbreviated to their shortest unique prefix. You
may use two hyphens instead of one. You may separate an option name
and its value with white space instead of an equals sign.
DESCRIPTION
This program is part of Netpbm(1).
pamsummcol reads a Netpbm image (PNM or PAM) and performs a summary
function over all the rows in each column (sum, mean, etc.). It pro-
duces an image of the same kind that the same width and depth as the
input, and one row high. Its sample values are the result of the sum-
mary.
pamsummcol performs the summary operation on each plane independently.
pamsummcol performs the operation on the actual sample values, not on
the light intensities represented by them in the case that the image is
a PGM or PPM image.
If you want to summarize by row instead of by column, run the input
through pamflip first (and if you want the output to be a single column
instead of a single row, use pamflip again).
If you want to summarize over the entire image (getting a one-tuple
output image), use pamsumm to get a summary row, pamflip to turn that
into a column, the pamsumm again to summarize the column.
If you want to summarize the individual samples in an entire image, in-
stead of by tuple, use pamsumm.
pamsummcol performs the operation on the actual sample values, not on
the light intensities represented by them in the case that the image is
a PGM or PPM image or PAM equivalent. You can use pnmgamma to convert
such an image to one with samples proportional to light intensity, and
then use pamsummcol on the result.
You can achieve the same thing as pamsummcol -mean with pamscale. Just
scale vertically to a single row, without scaling horizontally at all.
Use the pixel mixing method.
OPTIONS
In addition to the options common to all programs based on libnetpbm
(most notably -quiet, see
Common Options ⟨index.html#commonoptions⟩ ), pamsummcol recognizes the
following command line options:
You must specify exactly one of -sum, -mean, -min, or -max.
-sum
This option makes the summary function addition.
In each column and plane of the output row, the sample
value is the
sum of all the samples values in the same column and plane
of the input.
If a result is greater than the image maxval, it is clipped
to
the maxval.
-mean
This option makes the summary function arithmetic mean.
In each column and plane of the output row, the sample
value is the
mean of all the samples values in the same column and plane
of the input.
-min
This option makes the summary function arithmetic minimum.
In each column and plane of the output row, the sample
value is the
minimum of all the samples values in the same column and
plane of
the input.
-max
This option makes the summary function arithmetic maximum.
In each column and plane of the output row, the sample
value is
the maximum of all the samples values in the same column
and
plane of the input.
SEE ALSO
pamsumm(1), pamflip(1), pamfunc(1), pamarith(1), pamscale(1), pam(1),
HISTORY
pamsummcol was added to Netpbm in Release 10.21 (March 2004).
DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source. The master documentation is at
http://netpbm.sourceforge.net/doc/pamsummcol.html
netpbm documentation 25 January 2009 Pamsummcol User Manual(1)
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