1Pnm(3)                User Contributed Perl Documentation               Pnm(3)
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NAME

6       PDL::IO::Pnm -- pnm format I/O for PDL
7

SYNOPSIS

9         use PDL::IO::Pnm;
10         $im = wpnm $pdl, $file, $format[, $raw];
11         rpnm $stack->slice(':,:,:,(0)'),"PDL.ppm";
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DESCRIPTION

14       pnm I/O for PDL.
15

FUNCTIONS

17   pnminraw
18         Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
19                               int isbin; char* fd)
20
21       Read in a raw pnm file.
22
23       read a raw pnm file. The "type" argument is only there to determine the
24       type of the operation when creating "im" or trigger the appropriate
25       type conversion (maybe we want a byte+ here so that "im" follows
26       strictly the type of "type").
27
28       pnminraw does not process bad values.  It will set the bad-value flag
29       of all output piddles if the flag is set for any of the input piddles.
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31   pnminascii
32         Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
33                               int format; char* fd)
34
35       Read in an ascii pnm file.
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37       pnminascii does not process bad values.  It will set the bad-value flag
38       of all output piddles if the flag is set for any of the input piddles.
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40   pnmout
41         Signature: (a(m); int israw; int isbin; char *fd)
42
43       Write a line of pnm data.
44
45       This function is implemented this way so that threading works
46       naturally.
47
48       pnmout does not process bad values.  It will set the bad-value flag of
49       all output piddles if the flag is set for any of the input piddles.
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51   rpnm
52       Read a pnm (portable bitmap/pixmap, pbm/ppm) file into a piddle.
53
54         Usage:  $im = rpnm $file;
55
56       Reads a file in pnm format (ascii or raw) into a pdl (magic numbers
57       P1-P6).  Based on the input format it returns pdls with arrays of size
58       (width,height) if binary or grey value data (pbm and pgm) or
59       (3,width,height) if rgb data (ppm). This also means for a palette image
60       that the distinction between an image and its lookup table is lost
61       which can be a problem in cases (but can hardly be avoided when using
62       netpbm/pbmplus).  Datatype is dependent on the maximum
63       grey/color-component value (for raw and binary formats always PDL_B).
64       rpnm tries to read chopped files by zero padding the missing data (well
65       it currently doesn't, it barfs; I'll probably fix it when it becomes a
66       problem for me ;). You can also read directly into an existing pdl that
67       has to have the right size(!). This can come in handy when you want to
68       read a sequence of images into a datacube.
69
70       For details about the formats see appropriate manpages that come with
71       the netpbm/pbmplus packages.
72
73         $stack = zeroes(byte,3,500,300,4);
74         rpnm $stack->slice(':,:,:,(0)'),"PDL.ppm";
75
76       reads an rgb image (that had better be of size (500,300)) into the
77       first plane of a 3D RGB datacube (=4D pdl datacube). You can also do
78       inplace transpose/inversion that way.
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80   wpnm
81       Write a pnm (portable bitmap/pixmap, pbm/ppm) file into a file.
82
83         Usage:  $im = wpnm $pdl, $file, $format[, $raw];
84
85       Writes data in a pdl into pnm format (ascii or raw) (magic numbers
86       P1-P6).  The $format is required (normally produced by wpic) and
87       routine just checks if data is compatible with that format. All
88       conversions should already have been done. If possible, usage of wpic
89       is preferred. Currently RAW format is chosen if compliant with range of
90       input data. Explicit control of ASCII/RAW is possible through the
91       optional $raw argument. If RAW is set to zero it will enforce ASCII
92       mode. Enforcing RAW is somewhat meaningless as the routine will always
93       try to write RAW format if the data range allows (but maybe it should
94       reduce to a RAW supported type when RAW == 'RAW'?). For details about
95       the formats consult appropriate manpages that come with the
96       netpbm/pbmplus packages.
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BUGS

99       The stderr of the converters is redirected to a file. The filename is
100       currently generated in a probably non-portable way. A method that
101       avoids a file (and is portable) would be preferred.
102
103       "rpnm" currently relies on the fact that the header is separated from
104       the image data by a newline. This is not required by the p[bgp]m
105       formats (in fact any whitespace is allowed) but most of the pnm writers
106       seem to comply with that. Truncated files are currently treated
107       ungracefully ("rpnm" just barfs).
108

AUTHOR

110       Copyright (C) 1996,1997 Christian Soeller <c.soeller@auckland.ac.nz>
111       All rights reserved. There is no warranty. You are allowed to
112       redistribute this software / documentation under certain conditions.
113       For details, see the file COPYING in the PDL distribution. If this file
114       is separated from the PDL distribution, the copyright notice should be
115       included in the file.
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119perl v5.32.1                      2021-02-15                            Pnm(3)
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