1Pamtopfm User Manual(0)                                Pamtopfm User Manual(0)
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NAME

6       pamtopfm - Convert Netpbm image to PFM (Portable Float Map)
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SYNOPSIS

10       pamtopfm [-endian={big|little}] [-scale=float] [imagefile]
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12       All  options  can  be abbreviated to their shortest unique prefix.  You
13       may use two hyphens instead of one.  You may separate  an  option  name
14       and its value with white space instead of an equals sign.
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DESCRIPTION

18       This program is part of Netpbm(1).
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20       pamtopfm  reads  a  Netpbm  image (PNM or PAM) and converts it to a PFM
21       (Portable Float Map) image.
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23       The PFM (Portable Float Map) image format is a lot like PPM,  but  uses
24       floating  point  numbers with no maxval to achieve a High Dynamic Range
25       (HDR) format.  That means it doesn't have a concept of  absolute  color
26       and  it  can  represent generic light intensity information rather than
27       just visual information like PPM does.  For example,  two  pixels  that
28       are so close in intensity that the human eye cannot tell them apart are
29       not visually distinct, so a visual image format such as PPM would  have
30       no  reason  to use different sample values for them.  But an HDR format
31       would.
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33       There are details of the PFM format in the PFM Format Description" (1).
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35       USC's HDRShop program ⟨http://www.debevec.org/HDRShop⟩  and  a  program
36       called Lefty use it.
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38       pamtopfm creates a color PFM image if its input is RGB (PPM) and a non-
39       color PFM otherwise.
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41       Use pfmtopam(1) to convert a PFM image to Netpbm format.
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OPTIONS

46       -scale=float
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48              This specifies the scale factor of the PFM image.
49                   Scale factor is a component of the PFM format.
50                   Default is 1.0.
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53       -endian={big|little}
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55              This specifies the endianness of the PFM image.  The samples
56                   in the raster of a PFM image are 4 byte IEEE floating point
57                   numbers.  A parameter of the IEEE format, and therefore the
58              PFM
59                   format, is endianness, i.e. whether the specified bytes are
60                   ordered from low addresses to high addresses or vice versa.
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62              big means big endian -- the natural ordering;
63                   little means little-endian, the Intel-friendly ordering.
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65              Default is whichever endianness the machine on which pamtopfm
66                   runs  uses  internally,  which results in the faster execu‐
67              tion.
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SEE ALSO

73       Netpbm(1), pfmtopam(1), pam(1)
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HISTORY

77       pamtopfm was added to Netpbm in Release 10.22 (April 2004).
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DOCUMENT SOURCE

80       This manual page was generated by the Netpbm tool 'makeman'  from  HTML
81       source.  The master documentation is at
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83              http://netpbm.sourceforge.net/doc/pamtopfm.html
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85netpbm documentation             10 April 2004         Pamtopfm User Manual(0)