Manual: pamtopnm

Pamtopnm User Manual(1)				   General Commands Manual			     Pamtopnm User Manual(1)

NAME
       pamtopnm - convert PAM image to PBM, PGM, or PPM

SYNOPSIS
       pamtopnm

       [-assume]

       [pnmfile]

       Minimum	unique	abbreviation of option is acceptable.  You may use double hyphens instead of single hyphen to denote
       options.	 You may use white space in place of the equals sign to separate an option name from its value.

DESCRIPTION
       This program is part of Netpbm(1).

       pamtopnm reads a PAM image as input and produces an equivalent PBM, PGM, or PPM (i.e. PNM) image, whichever  is	most
       appropriate, as output.

       pamtopnm	 assumes the PAM image represents the information required for a PBM, PGM, or PPM image if its tuple type is
       "BLACKANDWHITE", "GRAYSCALE", or "RGB" and its depth and maxval are appropriate.	 If this is not the  case,  pamtopnm
       fails.

       However, you can override the tuple type requirement with the -assume option.

       pamtopnm	 produces a PPM image if the input PAM has depth 3 or 4; it produces PGM or PBM if the input PAM has depth 1
       or 2.  Whether it produced PGM or PBM depends upon the maxval: PBM for 1, PGM for anything higher.   The	 tuple	type
       does not play a role in determining the output type.  You can use Netpbm programs such as pgmtopgm to generate a dif‐
       ferent PNM output, but remember that Netpbm program that expects PGM input will take PBM and so on.

       Note  that it's possible for an image which is formally color to in fact contain only shades of gray and for an image
       which is formally grayscale to contain only black and white.  This program pays no attention to that;  an  RGB  input
       image  produces	a  PPM output image even if all the pixels are gray.  But you can use ppmtopgm to convert a PPM that
       you know is grayscale to the equivalent PGM, and you can use pamthreshold to convert a PGM image you  know  is  black
       and white to a black and white PAM image and then use pamtopnm to convert that to PBM.

       As  with any Netpbm program that reads PAM images, pamtopnm also reads PNM images as if they were PAM.  In that case,
       pamtopnm's functions reduces to simply copying the input to the output.	But this can be useful	in  a  program	that
       doesn't know whether its input is PAM or PNM but needs to feed it to a program that only recognizes PNM.

OPTIONS
       In  addition  to	 the  options common to all programs based on libnetpbm (most notably -quiet, see  Common Options ),
       pamtopnm recognizes the following command line option:

       -assume
	      When you specify -assume, you tell pamtopnm that you personally vouch for the fact that the tuples contain the
	      same data as belongs in the channels of a PBM, PGM, or PPM file.	The depth must still conform, though, so  to
	      truly  force  a  conversion, you may have to run the input through pamchannel first.  But be careful with -as‐
	      sume.  When you -assume, you make an -ass of u and me.

SEE ALSO
       pbmtopgm(1), pamditherbw(1), pgmtoppm(1), ppmtopgm(1), pamthreshold(1), pam(1), pnm(1), pbm(1), pgm(1), ppm(1)

HISTORY
       pamtopnm was new, along with the PAM format, in Netpbm 9.7 (August 2000).

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/pamtopnm.html

netpbm documentation				      02 February 2018				     Pamtopnm User Manual(1)