SYNOPSIS
pamsummcol { -sum | -mean | -min | -max } [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.

pamsummcol reads a Netpbm image (PNM or PAM) and performs a summary
function over all the rows in each column (sum, mean, etc.). It pro-
duces an image of the same kind that the same width and depth as the
input, and one row high. Its sample values are the result of the sum-
mary.

pamsummcol performs the summary operation on each plane independently.

pamsummcol 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.

If you want to summarize by row instead of by column, run the input
through pamflip first (and if you want the output to be a single col-
umn instead of a single row, use pamflip again).

If you want to summarize over the entire image instead of over columns
separately, use pamsumm.

pamsummcol 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. You can use pnmgamma to con-
vert such an image to one with samples proportional to light inten-
sity, and then use pamsummcol on the result.

You can achieve the same thing as pamsummcol -mean with pamscale.
Just scale vertically to a single row, without scaling horizontally at
all. Use the pixel mixing method.



OPTIONS
You must specify exactly one of -sum, -mean, -min, or -max.



-sum



-mean



-min



-max





SEE ALSO
pamsumm, pamscale, pamfunc, pamarith, pamscale, pam,


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



netpbm documentation 07 February 2004 Pamsummcol User Manual(0)