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Pamdepth User Manual(0)                                Pamdepth User Manual(0)



NAME
       pamdepth - change the maxval in a Netpbm image


SYNOPSIS
       pamdepth newmaxval [netpbmfile]


DESCRIPTION
       This program is part of Netpbm(1).

       pamdepth reads a Netpbm image as input, scales all the pixel values, and writes out the image with the new max-
       val.  Scaling the colors down to a smaller maxval will result in some loss of information.

       This program works on multi-image streams.

       Be careful of off-by-one errors when choosing the new maxval.  For instance, if you want the color values to be
       five bits wide, use a maxval of 31, not 32.

       One  important  use  of pamdepth is to convert a new format 2-byte-per-sample PNM file to the older 1-byte-per-
       sample format.  Before April 2000, essentially all raw (binary) format PNM files had a maxval less than 256 and
       one byte per sample, and many programs may rely on that.  If you specify a newmaxval less than 256, the result-
       ing file should be readable by any program that worked with PNM files before April 2000.


SEE ALSO
       pnm(1), pam(1), pnmquant(1), ppmdither(1) ppmbrighten(1) pamfunc(1)


HISTORY
       pamdepth was new in Netpbm 10.32 (February 2006).  It replaced pnmdepth, by Jef Poskanzer.  pamdepth  is  back-
       ward  compatible  with pnmdepth and adds the ability to process arbitrary PAM images and the ability to process
       multi-image input streams.  pnmdepth handled only PNM images and ignored all but the the first in any stream.



netpbm documentation             08 April 2000         Pamdepth User Manual(0)