Manual: pamsumm

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 function 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 specifica‐
       tions of PGM(1), PPM(1), and PAM(1), for the precise meanings of samples in these formats.  If you want to do  arith‐
       metic  on  light	 intensities  of such a visual image, you can use pnmgamma to convert it to one with samples propor‐
       tional 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 ex‐
       tract it and then pamsumm.

OPTIONS
       In addition to the options common to all programs based on libnetpbm (most notably  -quiet,  see	  Common Options  ),
       pamsumm 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.

       -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 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)