1Pnm(3) User Contributed Perl Documentation Pnm(3)
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6 PDL::IO::Pnm -- pnm format I/O for PDL
7
9 use PDL::IO::Pnm;
10 $im = wpnm $pdl, $file, $format[, $raw];
11 rpnm $stack->slice(':,:,:,(0)'),"PDL.ppm";
12
14 pnm I/O for PDL.
15
17 rpnm
18 Read a pnm (portable bitmap/pixmap, pbm/ppm) file into a piddle.
20 Reads a file in pnm format (ascii or raw) into a pdl (magic numbers
22 P1-P6). Based on the input format it returns pdls with arrays of size
23 (width,height) if binary or grey value data (pbm and pgm) or
24 (3,width,height) if rgb data (ppm). This also means for a palette image
25 that the distinction between an image and its lookup table is lost
26 which can be a problem in cases (but can hardly be avoided when using
27 netpbm/pbmplus). Datatype is dependent on the maximum grey/color-com‐
28 ponent value (for raw and binary formats always PDL_B). rpnm tries to
29 read chopped files by zero padding the missing data (well it currently
30 doesn't, it barfs; I'll probably fix it when it becomes a problem for
31 me ;). You can also read directly into an existing pdl that has to have
32 the right size(!). This can come in handy when you want to read a
33 sequence of images into a datacube.
34 For details about the formats see appropriate manpages that come with
36 the netpbm/pbmplus packages.
37 $im = rpnm $file;
39 $stack = zeroes(byte,3,500,300,4);
41 rpnm $stack->slice(':,:,:,(0)'),"PDL.ppm";
42 reads an rgb image (that had better be of size (500,300)) into the
44 first plane of a 3D RGB datacube (=4D pdl datacube). You can also do
45 inplace transpose/inversion that way.
46 wpnm
48 Write a pnm (portable bitmap/pixmap, pbm/ppm) file into a file.
50 Writes data in a pdl into pnm format (ascii or raw) (magic numbers
52 P1-P6). The $format is required (normally produced by wpic) and rou‐
53 tine just checks if data is compatible with that format. All conver‐
54 sions should already have been done. If possible, usage of wpic is pre‐
55 ferred. Currently RAW format is chosen if compliant with range of input
56 data. Explicit control of ASCII/RAW is possible through the optional
57 $raw argument. If RAW is set to zero it will enforce ASCII mode.
58 Enforcing RAW is somewhat meaningless as the routine will always try to
59 write RAW format if the data range allows (but maybe it should reduce
60 to a RAW supported type when RAW == 'RAW'?). For details about the for‐
61 mats consult appropriate manpages that come with the netpbm/pbmplus
62 packages.
63 $im = wpnm $pdl, $file, $format[, $raw];
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67 The stderr of the converters is redirected to a file. The filename is
68 currently generated in a probably non-portable way. A method that
69 avoids a file (and is portable) would be prefered.
70 "rpnm" currently relies on the fact that the header is separated from
72 the image data by a newline. This is not required by the p[bgp]m for‐
73 mats (in fact any whitespace is allowed) but most of the pnm writers
74 seem to comply with that. Truncated files are currently treated
75 ungracefully ("rpnm" just barfs).
76
78 Copyright (C) 1996,1997 Christian Soeller <c.soeller@auckland.ac.nz>
79 All rights reserved. There is no warranty. You are allowed to redis‐
80 tribute this software / documentation under certain conditions. For
81 details, see the file COPYING in the PDL distribution. If this file is
82 separated from the PDL distribution, the copyright notice should be
83 included in the file.
84
86 pnminraw
87 Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
89 int isbin; char* fd)
90 Read in a raw pnm file.
92 read a raw pnm file. The "type" argument is only there to determine the
94 type of the operation when creating "im" or trigger the appropriate
95 type conversion (maybe we want a byte+ here so that "im" follows
96 strictly the type of "type").
97 pnminascii
99 Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
101 int format; char* fd)
102 Read in an ascii pnm file.
104 pnmout
106 Signature: (a(m); int israw; int isbin; char *fd)
108 Write a line of pnm data.
110 This function is implemented this way so that threading works natu‐
112 rally.
113perl v5.8.8 2006-12-02 Pnm(3)