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 chan-
nels 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 ⟨index.html#commonoptions⟩ ), 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 channels, 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-Tes-
tImages/tree/master/SGI .
SEE ALSO
pnm(1), pam(1), pnmtosgi(1), pamstack(1)
AUTHOR
Copyright (C) 1994 by Ingo Wilken ( Ingo.Wilken@informatik.uni-olden-
burg.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)
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