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Ppmtoxpm User Manual(0) 						  Ppmtoxpm User Manual(0)

NAME
       ppmtoxpm - convert a PPM image to an X11 pixmap

SYNOPSIS
       ppmtoxpm [-name=xpmname] [-hexonly] [-rgb=rgb-textfile] [-alphamask=pgmfile] [ppmfile]

       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)

       ppmtoxpm  reads	a PPM image as input and produces X11 pixmap (version 3) as output.  This
       format can be loaded by the XPM library.

       In the XPM output, colors may be identified by name, such as "Red", or in hexadecimal, for
       example	"#FF0000".   In the hexadecimal format, there may be from 1 through 4 hexadecimal
       digits per RGB component.

       By default, ppmtoxpbm tries to find a name for each color in the image in the system color
       dictionary  <libppm.html#rgb.txt>  ,  and if it finds one, uses it.  If it doesn't it uses
       hexadecimal.  You can force ppmtoxpbm to use hexadecimal only with  the	-hexonly  option.
       You can specify a different color dictionary with the -rgb option.

       When  ppmtoxpm  uses  the hexadecimal format for identifying a color, it uses the one that
       uses the least number of hexadecimal digits that it takes to represent the maxval  of  the
       input  PPM.  E.g. if the maxval of the input PPM is 100, ppmtoxpm uses 2 digits per compo-
       nent, as in "#FF0000".

       Some programs do not properly handle one-digit-per-component hexadecimal color specifiers.
       They  see  the  wrong colors.  To produce an XPM that such a program can handle, make sure
       the maxval of the input PPM is greater than 15, such as by  running  it	through  pamdepth
       255.

   Color Code Lengths - Image Size
       In  the	XPM format, there is a palette ('color map') that assigns each color in the image
       to a unique sequence of printable characters called a color code, and a raster that  iden-
       tifies  the color of each pixel of the image with one of those color codes.  The length of
       the color code affects the size of the image stream.

       All color codes in an image are the same length, and ppmtoxpm tries to make it as short as
       possible.   That  length  is,  of course, determined by the number of colors in the image.
       ppmtoxpm counts the colors in the image, excluding those that will be transparent  in  the
       output  due to your alpha mask, and chooses a color code length accordingly.  There are 92
       printable characters that can be used in a color code.  Therefore, if you have 92 or fewer
       colors,	your  color  codes  will be one character.  If you have more than 92 but not more
       than 92 * 92, your color codes will be two characters.  And so on.

       There's one exception to the above: If you specify an alpha mask (the -alpha  option,  one
       unique  color  code represents 'transparent.'  This is true even if the alpha mask doesn't
       actually produce any transparent pixels.  So subtract one from the number of possible col-
       ors if you use -alpha.


OPTIONS
       -name=xpmname
	      This  option  specifies  the  prefix string which is specified in the resulting XPM
	      output.  If you don't use the -name  otpion,  ppmtoxpm  defaults	to  the  filename
	      (without	extension) of the ppmfile parameter.  If you do not specify -name or ppm-
	      file (i.e. your input is from Standard Input), the prefix string	defaults  to  the
	      string noname.

       -hexonly
	      This  option  says never to put color names in the XPM file, but rather to identify
	      names by hexadecimal strings that explicitly identify  RGB  component  intensities.
	      This  means the reader of the file need not have access to a suitable color dictio-
	      nary to interpret it.

	      This option was introduced in Netpbm 10.15 (April 2003).	Before that, it  was  the
	      default, overridden by specifying -rgb.

       -rgb=rgb-textfile
	      This  option  names the file in which the color dictionary you want to use resides.
	      By default, ppmtoxpm uses the system color dictionary <libppm.html#rgb.txt> .

	      This option in meaningless when you specify -hexonly.

	      Before Netpbm 10.15 (April 2003), ppmtoxpm did not default to the system color dic-
	      tionary.	 If  you  didn't specify -rgb, ppmtoxpbm would use only hexadecimal color
	      specifiers.

       -alphamask=pgmfile
	       This option names a PGM file to use as an alpha	(transparency)	mask.	The  file
	      must  contain  an  image the same dimensions as the input image.	ppmtoxpm marks as
	      transparent any pixel whose position in the alpha mask image is at most half white.

	      If you don't specify -alphamask, ppmtoxpm makes all pixels in the output opaque.

	      ppmcolormask is one way to generate an alpha mask file.  You might also generate it
	      by  extracting  transparency information from an XPM file with the -alphaout option
	      to xpmtoppm.

	      There are similar options on other Netpbm converters that convert from formats that
	      include transparency information too.

SEE ALSO
       ppmcolormask(1) , xpmtoppm(1) , pamdepth(1) , ppm(5)

       XPM Manual by Arnaud Le Hors lehors@mirsa.inria.fr

AUTHOR
       Copyright (C) 1990 by Mark W. Snitily.

       Permission  to  use,  copy, modify, and distribute this software and its documentation for
       any purpose and without fee is hereby granted, provided that the  above	copyright  notice
       appear in all copies and that both that copyright notice and this permission notice appear
       in supporting documentation.  This software is provided 'as is' without express or implied
       warranty.

       This  tool  was developed for Schlumberger Technologies, ATE Division, and with their per-
       mission is being made available to the public with the above copyright notice and  permis-
       sion notice.

       Upgraded  to  XPM2  by Paul Breslaw, Mecasoft SA, Zurich, Switzerland (paul@mecazh.uu.ch),
       November 8, 1990.

       Upgraded to XPM version 3 by Arnaud Le Hors(lehors@mirsa.inria.fr), April 9, 1991.

netpbm documentation			   Feb 22 2003			  Ppmtoxpm User Manual(0)
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