pamsumm



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] [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 you want a result that is independent of maxval but still in
                   integers, and your input is PNM, you can use pnmdepth to
                   convert to some standard maxval.  For example, if you  want
              the mean
                   intensity of a PPM image, on a scale of 0 to 99, do

                  pnmdepth 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)

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