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Pamsumm User Manual(0)                                  Pamsumm User Manual(0)



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, 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  inten-
       sities  of  such  a  visual image, you can use pnmgamma to convert 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 summa-
       rize  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
       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 ALSO
       pamsumm(1), pam(1),


HISTORY
       pamsumm was added to Netpbm in Release 10.21 (March 2004).



netpbm documentation           07 February 2004         Pamsumm User Manual(0)