NAME

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

SYNOPSIS

       pamtopfm [-endian={big|little}] [-scale=float] [imagefile]

       All  options can be abbreviated to their shortest unique prefix.  You may use two hyphens instead of one.
       You may separate an option name and its value with white space instead of an equals sign.

DESCRIPTION

       This program is part of Netpbm(1).

       pamtopfm reads a Netpbm image (PNM or PAM) and converts it to a PFM (Portable Float Map) image.

       The PFM (Portable Float Map) image format is a lot like PPM, but uses  floating  point  numbers  with  no
       maxval  to  achieve  a High Dynamic Range (HDR) format.  That means it doesn't have a concept of absolute
       color and it can represent generic light intensity information rather than just visual  information  like
       PPM  does.   For  example,  two pixels that are so close in intensity that the human eye cannot tell them
       apart are not visually distinct, so a visual image format such  as  PPM  would  have  no  reason  to  use
       different sample values for them.  But an HDR format would.

       There are details of the PFM format in the PFM Format Description" (1).

       USC's HDRShop program  and a program called Lefty use it.

       pamtopfm creates a color PFM image if its input is RGB (PPM) and a non-color PFM otherwise.

       Use pfmtopam(1) to convert a PFM image to Netpbm format.

OPTIONS

       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet, see  Common
       Options ), pamtopfm recognizes the following command line options:

       -scale=float

              This specifies the scale factor of the PFM image.
                   Scale factor is a component of the PFM format.
                   Default is 1.0.

       -endian={big|little}

              This specifies the endianness of the PFM image.  The samples
                   in the raster of a PFM image are 4 byte IEEE floating point
                   numbers.  A parameter of the IEEE format, and therefore the PFM
                   format, is endianness, i.e. whether the specified bytes are
                   ordered from low addresses to high addresses or vice versa.

              big means big endian -- the natural ordering;
                   little means little-endian, the Intel-friendly ordering.

              Default is whichever endianness the machine on which pamtopfm
                   runs uses internally, which results in the faster execution.

SEE ALSO

       Netpbm(1), pfmtopam(1), pam(1)

HISTORY

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

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master  documentation
       is at

              http://netpbm.sourceforge.net/doc/pamtopfm.html

netpbm documentation                              10 April 2004                          Pamtopfm User Manual(1)