1Ppmtobmp User Manual(0)                                Ppmtobmp User Manual(0)
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NAME

6       ppmtobmp - convert a PPM image into a BMP file
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SYNOPSIS

10       ppmtobmp
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12       [-windows]
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14       [-os2]
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16       [-bpp=bits_per_pixel]
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18       [-mapfile=filename]
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20       [ppmfile]
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22       Minimum  unique abbreviation of option is acceptable.  You may use dou‐
23       ble hyphens instead of single hyphen to denote options.   You  may  use
24       white space in place of the equals sign to separate an option name from
25       its value.
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DESCRIPTION

30       This program is part of Netpbm(1).
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32       ppmtobmp reads a PPM image as input and produces a Microsoft Windows or
33       OS/2 BMP file as output.
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OPTIONS

37       -windows
38              Tells  the  program  to  produce  a  Microsoft Windows BMP file.
39              (This is the default.)
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42       -os2   Tells the program to produce an OS/2 BMP file.   (Before  August
43              2000, this was the default).
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46       -bpp   This tells how many bits per pixel you want the BMP file to con‐
47              tain.  Only 1, 4, 8, and 24 are possible.  By default,  ppmtobmp
48              chooses  the smallest number with which it can represent all the
49              colors in the input image.  If you specify a number too small to
50              represent  all the colors in the input image, ppmtobmp tells you
51              and terminates.  You can use pnmquant or ppmdither to reduce the
52              number of colors in the image.
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55       -mapfile=filename
56              This  identifies  a  file  to  use as the BMP palette (aka 'col‐
57              ormap').  In one BMP subformat, the BMP stream contains  a  pal‐
58              ette  of  up  to  256 colors, and represents the image raster as
59              indices into that palette.  Normally,  ppmtobmp  takes  care  of
60              computing  a  suitable  palette, but if you are going to dissect
61              the BMP output in some way, you may want certain values for  the
62              palette  indices.   E.g. you might want red to be 13, where ppm‐
63              tobmp would (arbitrarily) choose 39.  In that case, you can con‐
64              struct the palette yourself and use this option to tell ppmtobmp
65              to use your palette.
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67              This option does not control what colors are in the output.  The
68              colors  in  the  output  are exactly those in the input, and the
69              palette you supply must contain at least all the colors that are
70              in  the  input.  You can use pnmremap to adjust your input image
71              so that it contains only colors from your palette.
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73              The palette file is a Netpbm format file with one pixel per pal‐
74              ette entry.  Each pixel must have a distinct color (no repeats).
75              The order of the BMP palette ppmtobmp generates is the order  of
76              the  pixels  in the palette file, going from top to bottom, left
77              to right.
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79              A BMP palette may have at most 256 colors, so the  palette  file
80              must have at most 256 pixels.
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82              You  may find pnmcolormap useful in generating the palette file.
83              pamseq too.
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85              This option was new in Netpbm 10.45 (December 2008).
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NOTES

92       To get a faithful reproduction of the input image, the  maxval  of  the
93       input  image  must  be 255.  If it is something else, the colors in the
94       BMP file may be slightly different from the colors in the input.
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96       Windows icons are not BMP files.  Use ppmtowinicon to create those.
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SEE ALSO

100       bmptoppm(1), ppmtowinicon(1), pnmquant(1),  ppmdither(1),  pnmremap(1),
101       ppm(1)
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AUTHOR

105       Copyright (C) 1992 by David W. Sanderson.
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109netpbm documentation            29 October 2008        Ppmtobmp User Manual(0)