Pamsumm User Manual(0) Pamsumm User Manual(0)NAMEpamsumm - Summarize the samples in a Netpbm image arithmetically
SYNOPSISpamsumm { -sum | -mean | -min | -max } [-normalize] [-brief] [image‐
file]
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, not on the
light intensities represented by them in the case that the image is a
PGM or PPM image or PAM equivalent. 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 sepa‐
rately), use pamsummcol. If you want to summarize by row, use a combi‐
nation of pamsummcol and pamflip. If you want to summarize a particu‐
lar plane, use pamchannel to extract it and then pamsumm.
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
image'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 intensity 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 ALSOpamsumm(1), pam(1),
HISTORYpamsumm was added to Netpbm in Release 10.21 (March 2004).
netpbm documentation 07 February 2004 Pamsumm User Manual(0)