1Pamtooctaveimg User Manual(0)                    Pamtooctaveimg User Manual(0)
2
3
4

NAME

6       pamtooctaveimg - convert a Netpbm image to a GNU Octave image
7
8

SYNOPSIS

10       pamtooctaveimg [netpbmfile]
11
12

DESCRIPTION

14       This program is part of Netpbm(1).
15
16       pamtooctaveimg  reads a Netpbm image as input and produces a GNU Octave
17       ⟨http://www.octave.org/⟩  image file as output.
18
19       An Octave image file (called 'Octave's image format' in Octave documen‐
20       tation)  is  a  particular  kind of Octave data file.  It describes two
21       matrices:
22
23
24
25       ·      the image itself as a list of indexes into a colormap, and
26
27       ·      the corresponding colormap as  a  list  of  {red,  green,  blue}
28              triplets.
29
30
31       An  Octave  data file is an ASCII text file that you use to import data
32       to Octave.
33
34       See the
35        Image                        Processing                        chapter
36       ⟨http://www.gnu.org/software/octave/doc/interpreter/Image-
37       Processing.html#Image-Processing⟩    of  the  GNU  Octave  manual   for
38       details.
39
40       pamtooctaveimg writes the output Octave image to Standard Output.
41
42

Arguments

44       netpbmfile  is  the  name  of  the file containing the input PNM or PAM
45       image, or - to indicate Standard Input.  If you don't  specify  netpbm‐
46       file,  the  input is from Standard Input.  pamtooctaveimg converts only
47       the first image in the input stream.
48
49
50

Examples

52          % pamtooctaveimg myimage.ppm > myimage.img
53          % octave
54          > [img,map] = loadimage("myimage.img");
55
56          # (At this point, img is an X by Y matrix and map is a 3 by M matrix.)
57
58          > imshow(img,map);   # Displays img with colormap map
59          > [r,g,b] = ind2rgb(img,map);
60
61          # (r, g, and b are now each X by Y matrices of color levels [0 to 1].)
62
63          > [newimg,newmap] = rgb2ind(r,b,g);   # Swap the blue and green channels.
64          > saveimage("newimage.ppm", newimg, "ppm", newmap);  # Save as a PPM file.
65
66
67

NOTES

69       There is no octavetopam program.  However, GNU Octave's saveimage  com‐
70       mand can save images in PPM format.
71
72
73

HISTORY

75       pamtooctaveimg was new in Netpbm 10.39 (June 2007).
76
77
78

SEE ALSO

80       octave(1), pam(1).
81
82

AUTHOR

84       Copyright (C) 2007 Scott Pakin, scott+pbm@pakin.org.
85
86
87
88netpbm documentation          27 June 2007<br /> Pamtooctaveimg User Manual(0)
Impressum