1Pamtopnm User Manual(0)                                Pamtopnm User Manual(0)
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NAME

6       pamtopnm - convert PAM image to PBM, PGM, or PPM
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SYNOPSIS

10       pamtopnm
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12       [-assume]
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14       [pnmfile]
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16       Minimum  unique abbreviation of option is acceptable.  You may use dou‐
17       ble hyphens instead of single hyphen to denote options.   You  may  use
18       white space in place of the equals sign to separate an option name from
19       its value.
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DESCRIPTION

23       This program is part of Netpbm(1).
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25       pamtopnm reads a PAM image as input and  produces  an  equivalent  PBM,
26       PGM, or PPM (i.e. PNM) image, whichever is most appropriate, as output.
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28       pamtopnm  assumes the PAM image represents the information required for
29       a PBM, PGM,  or  PPM  image  if  its  tuple  type  is  'BLACKANDWHITE',
30       'GRAYSCALE',  or  'RGB'  and  its depth and maxval are appropriate.  If
31       this is not the case, pamtopnm fails.
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33       However, you can override the tuple type requirement with  the  -assume
34       option.
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36       pamtopnm  produces  a  PPM  image if the input PAM has depth 3 or 4; it
37       produces PGM or PBM if the input PAM has depth 1 or 2.  Whether it pro‐
38       duced  PGM  or PBM depends upon the maxval: PBM for 1, PGM for anything
39       higher.  The tuple type does not play a role in determining the  output
40       type.   You can use Netpbm programs such as pgmtopgm to generate a dif‐
41       ferent PNM output, but remember that Netpbm program  that  expects  PGM
42       input will take PBM and so on.
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44       As  with  any Netpbm program that reads PAM images, pamtopnm also reads
45       PNM images as if they were PAM.  In  that  case,  pamtopnm's  functions
46       reduces  to  simply  copying  the input to the output.  But this can be
47       useful in a program that doesn't know whether its input is PAM  or  PNM
48       but needs to feed it to a program that only recognizes PNM.
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OPTIONS

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

65       pbmtopgm(1),  pamditherbw(1), pgmtoppm(1), ppmtopgm(1), pam(1), pnm(1),
66       pbm(1), pgm(1), ppm(1)
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HISTORY

71       pamtopnm was new, along with the PAM  format,  in  Netpbm  9.7  (August
72       2000).
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76netpbm documentation              10 May 2010          Pamtopnm User Manual(0)