Pamtooctaveimg User Manual(1General Commands ManuPamtooctaveimg User Manual(1)
NAME
pamtooctaveimg - convert a Netpbm image to a GNU Octave image
SYNOPSIS
pamtooctaveimg [netpbmfile]
DESCRIPTION
This program is part of Netpbm(1).
pamtooctaveimg reads a Netpbm image as input and produces a GNU Octave
⟨http://www.octave.org/⟩ image file as output.
An Octave image file (called "Octave's image format" in Octave documen-
tation) is a particular kind of Octave data file. It describes two ma-
trices:
• the image itself as a list of indexes into a colormap, and
• the corresponding colormap as a list of {red, green, blue} trip-
lets.
An Octave data file is an ASCII text file that you use to import data
to Octave.
See the
Image Processing chapter
⟨http://www.gnu.org/software/octave/doc/interpreter/Image-
Processing.html#Image-Processing⟩ of the GNU Octave manual for de-
tails.
pamtooctaveimg writes the output Octave image to Standard Output.
OPTIONS
There are no command line options defined specifically for pamtooc-
taveimg, but it recognizes the options common to all programs based on
libnetpbm (See
Common Options ⟨index.html#commonoptions⟩ .)
ARGUMENTS
netpbmfile is the name of the file containing the input PNM or PAM im-
age, or - to indicate Standard Input. If you don't specify netpbmfile,
the input is from Standard Input. pamtooctaveimg converts only the
first image in the input stream.
EXAMPLES
% pamtooctaveimg myimage.ppm > myimage.img
% octave
> [img,map] = loadimage("myimage.img");
# (At this point, img is an X by Y matrix and map is a 3 by M matrix.)
> imshow(img,map); # Displays img with colormap map
> [r,g,b] = ind2rgb(img,map);
# (r, g, and b are now each X by Y matrices of color levels [0 to 1].)
> [newimg,newmap] = rgb2ind(r,b,g); # Swap the blue and green channels.
> saveimage("newimage.ppm", newimg, "ppm", newmap); # Save as a PPM file.
NOTES
There is no octavetopam program. However, GNU Octave's saveimage com-
mand can save images in PPM format.
HISTORY
pamtooctaveimg was new in Netpbm 10.39 (June 2007).
AUTHOR
Copyright (C) 2007 Scott Pakin, scott+pbm@pakin.org.
SEE ALSO
octave(1), pam(1).
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/pamtooctaveimg.html
netpbm documentation 27 June 2007 Pamtooctaveimg User Manual(1)
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