1Pamendian User Manual(0)                              Pamendian User Manual(0)
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NAME

6       pamendian - reverse endianness of a Netpbm image
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SYNOPSIS

10       pamendian
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DESCRIPTION

14       This program is part of Netpbm(1).
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16       All  Netpbm formats that have samples in pure binary format with multi‐
17       ple bytes are defined to have them in big endian (most significant byte
18       first)  order.   However, there exist variations on these formats, pri‐
19       marily developed before official multibyte Netpbm formats existed, that
20       are  identical  to  Netpbm formats in every respect except that samples
21       are in little endian (least signficant byte first) order.
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23       pamendian reverses the byte order of the sample to convert between  the
24       two  formats.  If the input is true PAM, PGM, or PPM, the output is the
25       little endian variation on that format, and vice versa.
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27       The X Window System viewer xv expects the little  endian  variation  of
28       PGM and PPM.
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30       Programs  that  come with the Independent Jpeg Group's JPEG library are
31       known to use the little endian variation of PGM and PPM.
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33       The reason some programs use this variant is that at  one  time  during
34       Netpbm's  darkage(1),there was a version of Netpbm around that used it.
35       But it was never formally specified.
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37       This program takes input only on Standard Input.  Its output is  always
38       on Standard Output.
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40       You should never have to use this program with images generated by pro‐
41       grams in the Netpbm package or programs that use the Netpbm  libraries.
42       If  you  do,  that  probably means something needs to be fixed in those
43       programs.  The Netpbm converter for any graphics format that represents
44       numbers in little endian form should properly reverse the bytes to cre‐
45       ate correct Netpbm output.
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47       If you create a Netpbm image from a generic stream  of  samples,  using
48       rawtopgm  or  rawtoppm,  use  options  on those programs to declare the
49       endianness of your input, thus creating correct endianness in your  PGM
50       or PPM output.
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SEE ALSO

54       pamdepth(1), rawtopgm(1), rawtoppm(1), pnm(1)
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58netpbm documentation             16 March 2002        Pamendian User Manual(0)
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