Manual: pamsummcol

Pamsummcol User Manual(1)			   General Commands Manual			   Pamsummcol User Manual(1)

NAME
       pamsummcol - summarize (sum, average, etc) a Netpbm image by column

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(1).

       pamsummcol reads a Netpbm image (PNM or PAM) and performs a summary function over all the rows in each  column  (sum,
       mean,  etc.).   It  produces  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 summary.

       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 column instead of a single row, use pamflip again).

       If  you want to summarize over the entire image (getting a one-tuple output image), use pamsumm to get a summary row,
       pamflip to turn that into a column, the pamsumm again to summarize the column.

       If you want to summarize the individual samples in an entire image, instead of by tuple, 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 convert such an image to
       one with samples proportional to light intensity, 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
       In  addition  to	 the  options common to all programs based on libnetpbm (most notably -quiet, see  Common Options ),
       pamsummcol 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.
		   In each column and plane of the output row, the sample value is the
		   sum of all the samples values in the same column and plane of the input.
		   If a result is greater than the image maxval, it is clipped to
		   the maxval.

       -mean

	      This option makes the summary function arithmetic mean.
		   In each column and plane of the output row, the sample value is the
		   mean of all the samples values in the same column and plane of the input.

       -min

	      This option makes the summary function arithmetic minimum.
		   In each column and plane of the output row, the sample value is the
		   minimum of all the samples values in the same column and plane of
		   the input.

       -max

	      This option makes the summary function arithmetic maximum.
		   In each column and plane of the output row, the sample value is
		   the maximum of all the samples values in the same column and
		   plane of the input.

SEE ALSO
       pamsumm(1), pamflip(1), pamfunc(1), pamarith(1), pamscale(1), pam(1),

HISTORY
       pamsummcol 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/pamsummcol.html

netpbm documentation				       25 January 2009				   Pamsummcol User Manual(1)