1Pamtooctaveimg User Manual(0)                    Pamtooctaveimg User Manual(0)
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5       " "netpbm documentation"
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NAME

8       pamtooctaveimg - convert a Netpbm image to a GNU Octave image
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SYNOPSIS

12       pamtooctaveimg [netpbmfile]
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DESCRIPTION

16       This program is part of Netpbm(1).
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18       pamtooctaveimg  reads a Netpbm image as input and produces a GNU Octave
19       ⟨http://www.octave.org/⟩  image file as output.
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21       An Octave image file (called "Octave's image format" in Octave documen‐
22       tation)  is  a  particular  kind of Octave data file.  It describes two
23       matrices:
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27       ·      the image itself as a list of indexes into a colormap, and
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29       ·      the corresponding colormap as  a  list  of  {red,  green,  blue}
30              triplets.
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33       An  Octave  data file is an ASCII text file that you use to import data
34       to Octave.
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36       See the
37        Image                        Processing                        chapter
38       ⟨http://www.gnu.org/software/octave/doc/interpreter/Image-
39       Processing.html#Image-Processing⟩    of  the  GNU  Octave  manual   for
40       details.
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42       pamtooctaveimg writes the output Octave image to Standard Output.
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OPTIONS

46       There  are  no  command  line options defined specifically for pamtooc‐
47       taveimg, but it recognizes the options common to all programs based  on
48       libnetpbm (See
49        Common Options ⟨index.html#commonoptions⟩ .)
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ARGUMENTS

53       netpbmfile  is  the  name  of  the file containing the input PNM or PAM
54       image, or - to indicate Standard Input.  If you don't  specify  netpbm‐
55       file,  the  input is from Standard Input.  pamtooctaveimg converts only
56       the first image in the input stream.
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EXAMPLES

60          % pamtooctaveimg myimage.ppm > myimage.img
61          % octave
62          > [img,map] = loadimage("myimage.img");
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64          # (At this point, img is an X by Y matrix and map is a 3 by M matrix.)
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66          > imshow(img,map);   # Displays img with colormap map
67          > [r,g,b] = ind2rgb(img,map);
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69          # (r, g, and b are now each X by Y matrices of color levels [0 to 1].)
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71          > [newimg,newmap] = rgb2ind(r,b,g);   # Swap the blue and green channels.
72          > saveimage("newimage.ppm", newimg, "ppm", newmap);  # Save as a PPM file.
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NOTES

76       There is no octavetopam program.  However, GNU Octave's saveimage  com‐
77       mand can save images in PPM format.
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HISTORY

82       pamtooctaveimg was new in Netpbm 10.39 (June 2007).
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AUTHOR

86       Copyright (C) 2007 Scott Pakin, scott+pbm@pakin.org.
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SEE ALSO

90       octave(1), pam(1).
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DOCUMENT SOURCE

93       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
94       source.  The master documentation is at
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96              http://netpbm.sourceforge.net/doc/pamtooctaveimg.html
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98                                 27 June 2007    Pamtooctaveimg User Manual(0)
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