Manual: pamtopfm

Pamtopfm User Manual(1)				   General Commands Manual			     Pamtopfm User Manual(1)

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 repre‐
       sent 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)