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 pnminraw
18 Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
19 int isbin; PerlIO *fp)
20 Read in a raw pnm file.
22 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 pnminraw does not process bad values. It will set the bad-value flag
29 of all output ndarrays if the flag is set for any of the input
30 ndarrays.
31 pnminascii
33 Signature: (type(); byte+ [o] im(m,n); int ms => m; int ns => n;
34 int format; PerlIO *fp)
35 Read in an ascii pnm file.
37 pnminascii does not process bad values. It will set the bad-value flag
39 of all output ndarrays if the flag is set for any of the input
40 ndarrays.
41 pnmout
43 Signature: (a(m); int israw; int isbin; PerlIO *fp)
44 Write a line of pnm data.
46 This function is implemented this way so that broadcasting works
48 naturally.
49 pnmout does not process bad values. It will set the bad-value flag of
51 all output ndarrays if the flag is set for any of the input ndarrays.
52 rpnm
54 Read a pnm (portable bitmap/pixmap, pbm/ppm) file into an ndarray.
55 Usage: $im = rpnm $file;
57 Reads a file (or open file-handle) in pnm format (ascii or raw) into a
59 pdl (magic numbers P1-P6). Based on the input format it returns pdls
60 with arrays of size (width,height) if binary or grey value data (pbm
61 and pgm) or (3,width,height) if rgb data (ppm). This also means for a
62 palette image that the distinction between an image and its lookup
63 table is lost which can be a problem in cases (but can hardly be
64 avoided when using netpbm/pbmplus). Datatype is dependent on the
65 maximum grey/color-component value (for raw and binary formats always
66 PDL_B). rpnm tries to read chopped files by zero padding the missing
67 data (well it currently doesn't, it barfs; I'll probably fix it when it
68 becomes a problem for me ;). You can also read directly into an
69 existing pdl that has to have the right size(!). This can come in handy
70 when you want to read a sequence of images into a datacube.
71 For details about the formats see appropriate manpages that come with
73 the netpbm/pbmplus packages.
74 $stack = zeroes(byte,3,500,300,4);
76 rpnm $stack->slice(':,:,:,(0)'),"PDL.ppm";
77 reads an rgb image (that had better be of size (500,300)) into the
79 first plane of a 3D RGB datacube (=4D pdl datacube). You can also do
80 inplace transpose/inversion that way.
81 wpnm
83 Write a pnm (portable bitmap/pixmap, pbm/ppm) file into a file or open
84 file-handle.
85 Usage: $im = wpnm $pdl, $file, $format[, $raw];
87 Writes data in a pdl into pnm format (ascii or raw) (magic numbers
89 P1-P6). The $format is required (normally produced by wpic) and
90 routine just checks if data is compatible with that format. All
91 conversions should already have been done. If possible, usage of wpic
92 is preferred. Currently RAW format is chosen if compliant with range of
93 input data. Explicit control of ASCII/RAW is possible through the
94 optional $raw argument. If RAW is set to zero it will enforce ASCII
95 mode. Enforcing RAW is somewhat meaningless as the routine will always
96 try to write RAW format if the data range allows (but maybe it should
97 reduce to a RAW supported type when RAW == 'RAW'?). For details about
98 the formats consult appropriate manpages that come with the
99 netpbm/pbmplus packages.
100
102 "rpnm" currently relies on the fact that the header is separated from
103 the image data by a newline. This is not required by the p[bgp]m
104 formats (in fact any whitespace is allowed) but most of the pnm writers
105 seem to comply with that. Truncated files are currently treated
106 ungracefully ("rpnm" just barfs).
107
109 Copyright (C) 1996,1997 Christian Soeller <c.soeller@auckland.ac.nz>
110 All rights reserved. There is no warranty. You are allowed to
111 redistribute this software / documentation under certain conditions.
112 For details, see the file COPYING in the PDL distribution. If this file
113 is separated from the PDL distribution, the copyright notice should be
114 included in the file.
115perl v5.36.0 2023-01-20 Pnm(3)