Pamtooctaveimg User Manual(0) Pamtooctaveimg User Manual(0)NAMEpamtooctaveimg - convert a Netpbm image to a GNU Octave image
SYNOPSISpamtooctaveimg [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
matrices:
· the image itself as a list of indexes into a colormap, and
· the corresponding colormap as a list of {red, green, blue}
triplets.
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
details.
pamtooctaveimg writes the output Octave image to Standard Output.
Arguments
netpbmfile is the name of the file containing the input PNM or PAM
image, or - to indicate Standard Input. If you don't specify netpbm‐
file, 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.
HISTORYpamtooctaveimg was new in Netpbm 10.39 (June 2007).
SEE ALSOoctave(1), pam(1).
AUTHOR
Copyright (C) 2007 Scott Pakin, scott+pbm@pakin.org.
netpbm documentation 27 June 2007<br /> Pamtooctaveimg User Manual(0)
