Manual: sgitopnm

Sgitopnm User Manual(1)				   General Commands Manual			     Sgitopnm User Manual(1)

NAME
       sgitopnm - convert a SGI image file to PNM

SYNOPSIS
       sgitopnm

       [-verbose]

       [-channel c]

       [SgiFileName]

DESCRIPTION
       This program is part of Netpbm(1).

       sgitopnm	 reads an SGI image file as input and produces a PGM image for a 2-dimensional (1- or 2-channel) input file,
       and a PPM image for a 3-dimensional (3 or more channels) input file.

       Alternatively, the program produces a PGM image of any one of the channels in the input file.

       Before Netpbm 10.67 (June 2014), sgitopnm does not work on 2-channel SGI images.	 It fails if you try.

       If you don't specify the SgiFileName argument, input is from Standard Input.

       Before Netpbm 10.67 (June 2014), sgitopnm requires its input to be a seekable file, so for example you can't feed  it
       from a pipe.

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

       -verbose
	      Give some information about the SGI image file.

       -channel n
	      Extract channel n of the image as a PGM image.

	      Without this option, sgitopnm extracts the first 3 channels as a PPM image or, if the input has 1 or  2  chan‐
	      nels, extracts the first channel as a PGM image.

	      A 2-channel image is grayscale plus transparency, so you can get the transparency information with -channel=2.
	      You could then combine them into a PAM image of tuple type GRAYSCALE_ALPHA with pamstack.

REFERENCES
       The SGI image format specification version 1.0 is at ftp://ftp.sgi.com/graphics/grafica/sgiimage.html .

       There is an example SGI file at https://github.com/ZaaLabs/ZaaIL-TestImages/tree/master/SGI .

SEE ALSO
       pnm(1), pam(1), pnmtosgi(1), pamstack(1)

AUTHOR
       Copyright (C) 1994 by Ingo Wilken ( Ingo.Wilken@informatik.uni-oldenburg.de)

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/sgitopnm.html

netpbm documentation					25 April 2014				     Sgitopnm User Manual(1)