1 | #------------------------------------------------------------------------------
|
---|
2 | # File: PPM.pm
|
---|
3 | #
|
---|
4 | # Description: Read and write PPM meta information
|
---|
5 | #
|
---|
6 | # Revisions: 09/03/2005 - P. Harvey Created
|
---|
7 | #
|
---|
8 | # References: 1) http://netpbm.sourceforge.net/doc/ppm.html
|
---|
9 | # 2) http://netpbm.sourceforge.net/doc/pgm.html
|
---|
10 | # 3) http://netpbm.sourceforge.net/doc/pbm.html
|
---|
11 | #------------------------------------------------------------------------------
|
---|
12 |
|
---|
13 | package Image::ExifTool::PPM;
|
---|
14 |
|
---|
15 | use strict;
|
---|
16 | use vars qw($VERSION);
|
---|
17 | use Image::ExifTool qw(:DataAccess :Utils);
|
---|
18 |
|
---|
19 | $VERSION = '1.04';
|
---|
20 |
|
---|
21 | #------------------------------------------------------------------------------
|
---|
22 | # Read or write information in a PPM/PGM/PBM image
|
---|
23 | # Inputs: 0) ExifTool object reference, 1) Directory information reference
|
---|
24 | # Returns: 1 on success, 0 if this wasn't a valid PPM file, -1 on write error
|
---|
25 | sub ProcessPPM($$)
|
---|
26 | {
|
---|
27 | my ($exifTool, $dirInfo) = @_;
|
---|
28 | my $raf = $$dirInfo{RAF};
|
---|
29 | my $outfile = $$dirInfo{OutFile};
|
---|
30 | my $verbose = $exifTool->Options('Verbose');
|
---|
31 | my $out = $exifTool->Options('TextOut');
|
---|
32 | my ($buff, $num, $type, %info);
|
---|
33 | #
|
---|
34 | # read as much of the image as necessary to extract the header and comments
|
---|
35 | #
|
---|
36 | for (;;) {
|
---|
37 | if (defined $buff) {
|
---|
38 | # need to read some more data
|
---|
39 | my $tmp;
|
---|
40 | return 0 unless $raf->Read($tmp, 1024);
|
---|
41 | $buff .= $tmp;
|
---|
42 | } else {
|
---|
43 | return 0 unless $raf->Read($buff, 1024);
|
---|
44 | }
|
---|
45 | # verify this is a valid PPM file
|
---|
46 | return 0 unless $buff =~ /^P([1-6])\s+/g;
|
---|
47 | $num = $1;
|
---|
48 | # note: may contain comments starting with '#'
|
---|
49 | if ($buff =~ /\G#/gc) {
|
---|
50 | # must read more if we are in the middle of a comment
|
---|
51 | next unless $buff =~ /\G ?(.*\n(#.*\n)*)\s*/g;
|
---|
52 | $info{Comment} = $1;
|
---|
53 | next if $buff =~ /\G#/gc;
|
---|
54 | } else {
|
---|
55 | delete $info{Comment};
|
---|
56 | }
|
---|
57 | next unless $buff =~ /\G(\S+)\s+(\S+)\s/g;
|
---|
58 | $info{ImageWidth} = $1;
|
---|
59 | $info{ImageHeight} = $2;
|
---|
60 | $type = [qw{PPM PBM PGM}]->[$num % 3];
|
---|
61 | last if $type eq 'PBM'; # (no MaxVal for PBM images)
|
---|
62 | if ($buff =~ /\G\s*#/gc) {
|
---|
63 | next unless $buff =~ /\G ?(.*\n(#.*\n)*)\s*/g;
|
---|
64 | $info{Comment} = '' unless exists $info{Comment};
|
---|
65 | $info{Comment} .= $1;
|
---|
66 | next if $buff =~ /\G#/gc;
|
---|
67 | }
|
---|
68 | next unless $buff =~ /\G(\S+)\s/g;
|
---|
69 | $info{MaxVal} = $1;
|
---|
70 | last;
|
---|
71 | }
|
---|
72 | # validate numerical values
|
---|
73 | foreach (keys %info) {
|
---|
74 | next if $_ eq 'Comment';
|
---|
75 | return 0 unless $info{$_} =~ /^\d+$/;
|
---|
76 | }
|
---|
77 | if (defined $info{Comment}) {
|
---|
78 | $info{Comment} =~ s/^# ?//mg; # remove "# " at the start of each line
|
---|
79 | $info{Comment} =~ s/\n$//; # remove trailing newline
|
---|
80 | }
|
---|
81 | $exifTool->SetFileType($type);
|
---|
82 | my $len = pos($buff);
|
---|
83 | #
|
---|
84 | # rewrite the file if requested
|
---|
85 | #
|
---|
86 | if ($outfile) {
|
---|
87 | my $newValueHash;
|
---|
88 | my $newComment = $exifTool->GetNewValues('Comment', \$newValueHash);
|
---|
89 | my $oldComment = $info{Comment};
|
---|
90 | if (Image::ExifTool::IsOverwriting($newValueHash, $oldComment)) {
|
---|
91 | ++$exifTool->{CHANGED};
|
---|
92 | if ($verbose > 1) {
|
---|
93 | print $out " - Comment = '$oldComment'\n" if defined $oldComment;
|
---|
94 | print $out " + Comment = '$newComment'\n" if defined $newComment;
|
---|
95 | }
|
---|
96 | } else {
|
---|
97 | $newComment = $oldComment; # use existing comment
|
---|
98 | }
|
---|
99 | my $hdr = "P$num\n";
|
---|
100 | if (defined $newComment) {
|
---|
101 | $newComment =~ s/\n/\n# /g;
|
---|
102 | $hdr .= "# $newComment\n";
|
---|
103 | }
|
---|
104 | $hdr .= "$info{ImageWidth} $info{ImageHeight}\n";
|
---|
105 | $hdr .= "$info{MaxVal}\n" if $type ne 'PBM';
|
---|
106 | # write header and start of image
|
---|
107 | Write($outfile, $hdr, substr($buff, $len)) or return -1;
|
---|
108 | # copy over the rest of the image
|
---|
109 | while ($raf->Read($buff, 0x10000)) {
|
---|
110 | Write($outfile, $buff) or return -1;
|
---|
111 | }
|
---|
112 | return 1;
|
---|
113 | }
|
---|
114 | #
|
---|
115 | # save extracted information
|
---|
116 | #
|
---|
117 | if ($verbose > 2) {
|
---|
118 | print $out "$type header ($len bytes):\n";
|
---|
119 | Image::ExifTool::HexDump(\$buff, $len, Out => $out);
|
---|
120 | }
|
---|
121 | my $tag;
|
---|
122 | foreach $tag (qw{Comment ImageWidth ImageHeight MaxVal}) {
|
---|
123 | $exifTool->FoundTag($tag, $info{$tag}) if defined $info{$tag};
|
---|
124 | }
|
---|
125 | return 1;
|
---|
126 | }
|
---|
127 |
|
---|
128 | 1; # end
|
---|
129 |
|
---|
130 | __END__
|
---|
131 |
|
---|
132 | =head1 NAME
|
---|
133 |
|
---|
134 | Image::ExifTool::PPM - Read and write PPM meta information
|
---|
135 |
|
---|
136 | =head1 SYNOPSIS
|
---|
137 |
|
---|
138 | This module is used by Image::ExifTool
|
---|
139 |
|
---|
140 | =head1 DESCRIPTION
|
---|
141 |
|
---|
142 | This module contains definitions required by Image::ExifTool to read and
|
---|
143 | write PPM (Portable Pixel Map), PGM (Portable Gray Map) and PBM (Portable
|
---|
144 | BitMap) images.
|
---|
145 |
|
---|
146 | =head1 AUTHOR
|
---|
147 |
|
---|
148 | Copyright 2003-2007, Phil Harvey (phil at owl.phy.queensu.ca)
|
---|
149 |
|
---|
150 | This library is free software; you can redistribute it and/or modify it
|
---|
151 | under the same terms as Perl itself.
|
---|
152 |
|
---|
153 | =head1 REFERENCES
|
---|
154 |
|
---|
155 | =over 4
|
---|
156 |
|
---|
157 | =item L<http://netpbm.sourceforge.net/doc/ppm.html>
|
---|
158 |
|
---|
159 | =item L<http://netpbm.sourceforge.net/doc/pgm.html>
|
---|
160 |
|
---|
161 | =item L<http://netpbm.sourceforge.net/doc/pbm.html>
|
---|
162 |
|
---|
163 | =back
|
---|
164 |
|
---|
165 | =head1 SEE ALSO
|
---|
166 |
|
---|
167 | L<Image::ExifTool::TagNames/PPM Tags>,
|
---|
168 | L<Image::ExifTool(3pm)|Image::ExifTool>
|
---|
169 |
|
---|
170 | =cut
|
---|
171 |
|
---|