Pamsumm User Manual(1) General Commands Manual Pamsumm User Manual(1)
NAME
pamsumm - Summarize the samples in a Netpbm image arithmetically
SYNOPSIS
pamsumm { -sum | -mean | -min | -max } [-normalize] [-brief] [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).
pamsumm reads a Netpbm image (PNM or PAM) and performs a summary func-
tion over all the samples in all the rows, columns, and planes and
prints the result to Standard Output.
pamsumm performs the operation on the actual sample values. In the case
of a PGM or PPM or PAM equivalent (i.e. a visual image), this is not the
same as the light intensities represented by those samples. See the
format specifications of PGM(1), PPM(1), and PAM(1), for the precise
meanings of samples in these formats. If you want to do arithmetic on
light intensities of such a visual image, you can use pnmgamma to con-
vert it to one with samples proportional to light intensity, and then
use pamsumm on the result.
If you want to summarize by column (e.g. add up the columns separately),
use pamsummcol. If you want to summarize by row, use a combination of
pamsummcol and pamflip. If you want to summarize a particular plane,
use pamchannel to extract it and then pamsumm.
OPTIONS
In addition to the options common to all programs based on libnetpbm
(most notably -quiet, see ]8;;index.html#commonoptions\ Common Options]8;;\ ), pamsumm recognizes the fol-
lowing command line options:
You must specify exactly one of -sum, -mean, -min, or -max.
-sum
This option makes the summary function addition.
-mean
This option makes the summary function arithmetic mean.
-min
This option makes the summary function arithmetic minimum.
-max
This option makes the summary function arithmetic maximum.
-normalize
This option causes each sample to be normalized to a fraction
(in the range 0..1) so the result is independent of the im-
age's
maxval. E.g. if you request the mean of an image which has
maxval
200 and all the samples have value 50, pamsumm will give you
50 as an answer. But pamsumm -normalize will give you .25.
If instead you want a result that is independent of maxval but
still
in integers, you can use pamdepth to convert the input to
some
standard maxval and not use -normalize. For example, if you
want
the mean brightness of a PPM image, on a scale of 0 to 99,
do
pamdepth 99 myimage.ppm | pamsumm -mean
This option was new in Netpbm 10.22 (April 2004)
-brief
This option causes pamsumm to display the answer as a bare
number, rather than in a complete sentence.
This option was new in Netpbm 10.22 (April 2004)
SEE ALSO
pamsummcol(1), pam(1),
HISTORY
pamsumm 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/pamsumm.html
netpbm documentation 26 October 2012 Pamsumm User Manual(1)
Generated by dwww version 1.16 on Tue Dec 16 04:19:07 CET 2025.