source: main/trunk/greenstone2/perllib/plugins/HTMLImagePlugin.pm

Last change on this file was 28563, checked in by kjdon, 10 years ago

changing some util:: methods to FileUtils:: methods
  • Property svn:keywords set to Author Date Id Revision
File size: 37.3 KB
Line 
1###########################################################################
2#
3# HTMLImagePlugin.pm -- Context-based image indexing plugin for HTML documents
4#
5# A component of the Greenstone digital library software
6# from the New Zealand Digital Library Project at the
7# University of Waikato, New Zealand.
8#
9# Copyright (C) 2001 New Zealand Digital Library Project
10#
11# This program is free software; you can redistribute it and/or modify
12# it under the terms of the GNU General Public License as published by
13# the Free Software Foundation; either version 2 of the License, or
14# (at your option) any later version.
15#
16# This program is distributed in the hope that it will be useful,
17# but WITHOUT ANY WARRANTY; without even the implied warranty of
18# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19# GNU General Public License for more details.
20#
21# You should have received a copy of the GNU General Public License
22# along with this program; if not, write to the Free Software
23# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24#
25###########################################################################
26
27# DESCRIPTION:
28#
29# Extracts images and associated text and metadata from
30# web pages as individual documents for indexing. Thumbnails
31# are created from each image for browsing purposes.
32#
33# Options are available for configuring the aggressiveness of the
34# associated text extraction mechanisms. A higher level of
35# aggressiveness will extract more text and consequently
36# may mean lower accuracy (precision); however, it may also
37# retrieve more of the relevant images from the collection (recall).
38# Lower levels of aggressiveness maybe result in slightly faster
39# collection builds at the import stage.
40#
41# HTMLImagePlugin is a subclass of HTMLPlug (i.e. it will index pages also
42# if required). It can be used in place of HTMLPlugin to index both
43# pages and their images.
44#
45# REQUIREMENTS:
46#
47# The ImageMagick image manipulation is used to create
48# thumbnails and extract some image metadata. (Available
49# from http://www.imagemagick.org/)
50#
51# Unix:
52# Many Linux distributions contain ImageMagick.
53#
54# Windows:
55# ImageMagick can be downloaded from the website above.
56# Make sure the system path includes the ImageMagick binaries
57# before using HTMLImagePlugin.
58#
59# NOTE: NT/2000/XP contain a filesystem utility 'convert.exe'
60# with the same name as the image conversion utility. The
61# ImageMagick FAQ recommends renaming the filesystem
62# utility (e.g. to 'fsconvert.exe') to avoid this clash.
63#
64# USAGE:
65#
66# An image document consists of metadata elements:
67#
68# OriginalFilename, FilePath, Filename, FileExt, FileSize,
69# Width, Height, URL, PageURL, ThumbURL, CacheURL, CachePageURL
70# ImageText, PageTitle
71#
72# Most of these are only useful in format strings (e.g. ThumbURL,
73# Filename, URL, PageURL, CachePageURL).
74#
75# ImageText, as the name suggests contains the indexable text.
76# (unless using the -document_text plugin option)
77#
78# Since image documents are made up of metadata elements
79# alone, format strings are needed to display them properly.
80# NOTE: The receptionist will only display results (e.g. thumbnails)
81# in 4 columns if the format string begins with "<td><table>".
82#
83# The example below takes the user to the image within the
84# source HTML document rather than using a format string
85# on DocumentText to display the image document itself.
86#
87# Example collect.cfg:
88#
89# ...
90#
91# indexes document:ImageText document:text
92# defaultindex document:ImageText
93#
94# collectionmeta .document:ImageText "images"
95# collectionmeta .document:text "documents"
96#
97# ...
98#
99# plugin HTMLImagePlugin -index_pages -aggressiveness 6
100#
101# ...
102#
103# format SearchVList '<td>{If}{[Title],[link][icon]&nbsp;[Title][[/link],
104# <table><tr><td align="center"><a href="[CachePageURL]">
105# <img src="[ThumbURL]"></a></td></tr><tr><td align="center">
106# <a href="[CachePageURL]"><font size="-1">[OriginalFilename]</font></a>
107# <br>[Width]x[Height]</td></tr></table>}</td>'
108#
109# ...
110#
111
112package HTMLImagePlugin;
113
114use HTMLPlugin;
115use ghtml;
116use unicode;
117use util;
118use strict; # 'subs';
119no strict 'refs'; # allow filehandles to be variables and viceversa
120
121sub BEGIN {
122 @HTMLImagePlugin::ISA = qw( HTMLPlugin );
123}
124
125my $aggressiveness_list =
126 [ { 'name' => "1",
127 'desc' => "{HTMLImagePlugin.aggressiveness.1}" },
128 { 'name' => "2",
129 'desc' => "{HTMLImagePlugin.aggressiveness.2}" },
130 { 'name' => "3",
131 'desc' => "{HTMLImagePlugin.aggressiveness.3}" },
132 { 'name' => "4",
133 'desc' => "{HTMLImagePlugin.aggressiveness.4}" },
134 { 'name' => "5",
135 'desc' => "{HTMLImagePlugin.aggressiveness.5}" },
136 { 'name' => "6",
137 'desc' => "{HTMLImagePlugin.aggressiveness.6}" },
138 { 'name' => "7",
139 'desc' => "{HTMLImagePlugin.aggressiveness.7}" },
140 { 'name' => "8",
141 'desc' => "{HTMLImagePlugin.aggressiveness.8}" },
142 { 'name' => "9",
143 'desc' => "{HTMLImagePlugin.aggressiveness.9}" } ];
144
145my $arguments =
146 [ { 'name' => "aggressiveness",
147 'desc' => "{HTMLImagePlugin.aggressiveness}",
148 'type' => "int",
149 'list' => $aggressiveness_list,
150 'deft' => "3",
151 'reqd' => "no" },
152 { 'name' => "index_pages",
153 'desc' => "{HTMLImagePlugin.index_pages}",
154 'type' => "flag",
155 'reqd' => "no" },
156 { 'name' => "no_cache_images",
157 'desc' => "{HTMLImagePlugin.no_cache_images}",
158 'type' => "flag",
159 'reqd' => "no" },
160 { 'name' => "min_size",
161 'desc' => "{HTMLImagePlugin.min_size}",
162 'type' => "int",
163 'deft' => "2000",
164 'reqd' => "no" },
165 { 'name' => "min_width",
166 'desc' => "{HTMLImagePlugin.min_width}",
167 'type' => "int",
168 'deft' => "50",
169 'reqd' => "no" },
170 { 'name' => "min_height",
171 'desc' => "{HTMLImagePlugin.min_height}",
172 'type' => "int",
173 'deft' => "50",
174 'reqd' => "no" },
175 { 'name' => "thumb_size",
176 'desc' => "{HTMLImagePlugin.thumb_size}",
177 'type' => "int",
178 'deft' => "100",
179 'reqd' => "no" },
180 { 'name' => "convert_params",
181 'desc' => "{HTMLImagePlugin.convert_params}",
182 'type' => "string",
183 'deft' => "",
184 'reqd' => "no" },
185 { 'name' => "min_near_text",
186 'desc' => "{HTMLImagePlugin.min_near_text}",
187 'type' => "int",
188 'deft' => "10",
189 'reqd' => "no" },
190 { 'name' => "max_near_text",
191 'desc' => "{HTMLImagePlugin.max_near_text}",
192 'type' => "int",
193 'deft' => "400",
194 'reqd' => "no" },
195 { 'name' => "smallpage_threshold",
196 'desc' => "{HTMLImagePlugin.smallpage_threshold}",
197 'type' => "int",
198 'deft' => "2048",
199 'reqd' => "no" },
200 { 'name' => "textrefs_threshold",
201 'desc' => "{HTMLImagePlugin.textrefs_threshold}",
202 'type' => "int",
203 'deft' => "2",
204 'reqd' => "no" },
205 { 'name' => "caption_length",
206 'desc' => "{HTMLImagePlugin.caption_length}",
207 'type' => "int",
208 'deft' => "80",
209 'reqd' => "no" },
210 { 'name' => "neartext_length",
211 'desc' => "{HTMLImagePlugin.neartext_length}",
212 'type' => "int",
213 'deft' => "300",
214 'reqd' => "no" },
215 { 'name' => "document_text",
216 'desc' => "{HTMLImagePlugin.document_text}",
217 'type' => "flag",
218 'reqd' => "no" } ];
219
220my $options = { 'name' => "HTMLImagePlugin",
221 'desc' => "{HTMLImagePlugin.desc}",
222 'abstract' => "no",
223 'inherits' => "yes",
224 'args' => $arguments };
225
226sub new {
227 my ($class) = shift (@_);
228 my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
229 push(@$pluginlist, $class);
230
231 push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
232 push(@{$hashArgOptLists->{"OptList"}},$options);
233
234 my $self = new HTMLPlugin($pluginlist, $inputargs, $hashArgOptLists);
235
236 # init class variables
237 $self->{'textref'} = undef; # init by read_file fn
238 $self->{'htdoc_obj'} = undef; # init by process fn
239 $self->{'htpath'} = undef; # init by process fn
240 $self->{'hturl'} = undef; # init by process fn
241 $self->{'plaintext'} = undef; # HTML stripped version - only init if needed by raw_neartext sub
242 $self->{'smallpage'} = 0; # set by process fn
243 $self->{'images_indexed'} = undef; # num of images indexed - if 1 or 2 then we know page is small
244 $self->{'initialised'} = undef; # flag (see set_extraction_options())
245
246 return bless $self, $class;
247}
248
249# if indexing pages, let HTMLPlugin do it's stuff
250# image extraction done through read()
251sub process {
252 my $self = shift(@_);
253 my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
254 $self->{'imglist'} = ();
255 if ( $self->{'index_pages'} ) {
256 my $ok = $self->SUPER::process($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli);
257 if ( ! $ok ) { return $ok }
258 $self->{'htdoc_obj'} = $doc_obj;
259 }
260 # else use URL for referencing
261 #if ( $file =~ /(.*)[\/\\]/ ) { $self->{'htpath'} = $1; } else { $self->{'htpath'} = $file; }
262
263 $self->{'htpath'} = $base_dir if (-d $base_dir);
264 if ( $file =~ /(.*)[\/\\]/ ) { $self->{'htpath'} .= "/$1"; }
265 $self->{'htpath'} =~ s/\\/\//g; # replace \ with /
266
267 $self->{'hturl'} = "http://$file";
268 $self->{'hturl'} =~ s/\\/\//g; # for windows
269 ($self->{'filename'}) = $file =~ /.*[\/\\](.*)/;
270 ($self->{'base_path'}) = $file =~ /(.*)[\/\\]/i;
271 if ( ( -s "$base_dir/$file") <= $self->{'smallpage_threshold'} ) {
272 $self->{'smallpage'} = 1;
273 } else { $self->{'smallpage'} = 0; }
274
275 if ( defined($self->{'initialised'}) ) { return 1; }
276 else {
277 $self->{'initialised'} = $self->set_extraction_options($base_dir =~ /^(.*?)\/import/i);
278 return $self->{'initialised'};
279 }
280}
281
282# get complex configuration options from configuration files
283# -- $GSDLCOLLECTION/etc/HTMLImagePlugin.cfg (tag sets for aggr 2+)
284# -- $GSDLHOME/etc/packages/phind/stopword/en/brown.sw (stopwords for aggr 5+)
285
286# If there's no HTMLImagePlugin.cfg file we'll use the following default values
287my $defaultcfg = '
288<delimitertagset>
289 <setname>Caption</setname>
290 <taggroup>font</taggroup>
291 <taggroup>tt</taggroup>
292 <taggroup>small</taggroup>
293 <taggroup>b</taggroup>
294 <taggroup>i</taggroup>
295 <taggroup>u</taggroup>
296 <taggroup>em</taggroup>
297 <taggroup>td</taggroup>
298 <taggroup>li</taggroup>
299 <taggroup>a</taggroup>
300 <taggroup>p</taggroup>
301 <taggroup>tr</taggroup>
302 <taggroup>center</taggroup>
303 <taggroup>div</taggroup>
304 <taggroup>caption</taggroup>
305 <taggroup>br</taggroup>
306 <taggroup>ul</taggroup>
307 <taggroup>ol</taggroup>
308 <taggroup>table</taggroup>
309 <taggroup>hr</taggroup>
310</delimitertagset>
311
312<delimitertagset>
313 <setname>Neartext</setname>
314 <taggroup>tr|hr|table|h\d|img|body</taggroup>
315 <taggroup>td|tr|hr|table|h\d|img|body</taggroup>
316 <taggroup>p|br|td|tr|hr|table|h\d|img|body</taggroup>
317 <taggroup>font|p|i|b|em|img</taggroup>
318</delimitertagset>
319';
320
321sub set_extraction_options() {
322 my ($self, $collpath) = @_;
323 my ($filepath);
324
325 print {$self->{'outhandle'}} "HTMLImagePlugin: Initialising\n"
326 if $self->{'verbosity'} > 1;
327 # etc/HTMLImagePlugin.cfg (XML)
328 # tag sets for captions and neartext
329 if ( $self->{'aggressiveness'} > 1 && $self->{'aggressiveness'} != 9 ) {
330 $self->{'delims'} = [];
331 $self->{'cdelims'} = [];
332 my ($cfg, @tagsets, $tagset, $type, @delims);
333
334 $filepath = "$collpath/etc/HTMLImagePlugin.cfg";
335 if ( open CFG, "<$filepath" ) {
336 while (<CFG>) { $cfg .= $_ }
337 close CFG;
338 } else {
339 $cfg = $defaultcfg;
340 }
341
342 (@tagsets) =
343 $cfg =~ /<delimitertagset>(.*?)<\/delimitertagset>/igs;
344 foreach $tagset ( @tagsets ) {
345 ($type) = $tagset =~ /<setname>(.*?)<\/setname>/i;
346 if ( lc($type) eq "caption" ) {
347 (@{$self->{'cdelims'}}) = $tagset =~ /<taggroup>(.*?)<\/taggroup>/igs;
348 }
349 elsif ( lc($type) eq "neartext" ) {
350 (@{$self->{'delims'}}) = $tagset =~ /<taggroup>(.*?)<\/taggroup>/igs;
351 }
352 }
353
354 # output a warning if there seem to be no delimiters
355 if ( scalar(@{$self->{'cdelims'}} == 0)) {
356 print {$self->{'outhandle'}} "HTMLImagePlugin: Warning: no caption delimiters found in $filepath\n";
357 }
358 if ( scalar(@{$self->{'delims'}} == 0)) {
359 print {$self->{'outhandle'}} "HTMLImagePlugin: Warning: no neartext delimiters found in $filepath\n";
360 }
361 }
362
363 # get stop words for textual reference extraction
364 # TODO: warnings scroll off. Would be best to output them again at end of import
365 if ( $self->{'aggressiveness'} >=5 && $self->{'aggressiveness'} != 9 ) {
366 $self->{'stopwords'} = ();
367 $filepath = &FileUtils::filenameConcatenate($ENV{'GSDLHOME'}, "etc", "packages", "phind", "stopword", "en", "brown.sw");
368 if ( open STOPWORDS, "<$filepath" ) {
369 while ( <STOPWORDS> ) {
370 chomp;
371 $self->{'stopwords'}{$_} = 1;
372 }
373 close STOPWORDS;
374 } else {
375 print {$self->{'outhandle'}} "HTMLImagePlugin: Warning: couldn't open stopwords file at $filepath ($!)\n";
376 }
377
378 }
379
380 if ( $self->{'neartext_length'} > $self->{'max_near_text'} ) {
381 $self->{'max_near_text'} = $self->{'neartext_length'} * 1.33;
382 print {$self->{'outhandle'}} "HTMLImagePlugin: Warning: adjusted max_text to $self->{'max_near_text'}\n";
383 }
384 if ( $self->{'caption_length'} > $self->{'max_near_text'} ) {
385 $self->{'max_near_text'} = $self->{'caption_length'} * 1.33;
386 print {$self->{'outhandle'}} "HTMLImagePlugin: Warning: adjusted max_text to $self->{'max_near_text'}\n";
387 }
388
389 return 1;
390}
391
392# return number of files processed, undef if can't recognise, -1 if
393# cant process
394# Note that $base_dir might be "" and that $file might
395# include directories
396sub read {
397 my ($self, $pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs, $total_count, $gli) = (@_);
398 my ($doc_obj, $section, $filepath, $imgtag, $pos, $context, $numdocs, $tndir, $imgs);
399 # forward normal read (runs HTMLPlugin if index_pages T)
400 my $ok = $self->SUPER::read($pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs, $total_count, $gli);
401 if ( ! $ok ) { return $ok } # what is this returning??
402
403 my $outhandle = $self->{'outhandle'};
404 my $textref = $self->{'textref'};
405 my $htdoc_obj = $self->{'htdoc_obj'};
406 $numdocs = 0;
407 $base_dir =~ /(.*)\/.*/;
408 $tndir = "$1/archives/thumbnails"; # TODO: this path shouldn't be hardcoded?
409 &FileUtils::makeAllDirectories($tndir) unless -e "$tndir";
410
411 $imgs = \%{$self->{'imglist'}};
412 my $nimgs = $self->get_img_list($textref);
413 $self->{'images_indexed'} = $nimgs;
414 if ( $nimgs > 0 ) {
415 my @fplist = (sort { $imgs->{$a}{'pos'} <=> $imgs->{$b}{'pos'} } keys %{$imgs});
416 my $i = 0;
417 foreach $filepath ( @fplist ) {
418 $pos = $imgs->{$filepath}{'pos'};
419 $context = substr ($$textref, $pos - 50, $pos + 50); # grab context (quicker)
420 ($imgtag) = ($context =~ /(<(?:img|a|body)\s[^>]*$filepath[^>]*>)/is );
421 if (! defined($imgtag)) { $imgtag = $filepath }
422 print $outhandle "HTMLImagePlugin: extracting $filepath\n"
423 if ( $self->{'verbosity'} > 1 );
424 $doc_obj = new doc ("", "indexed_doc", $self->{'file_rename_method'});
425 $section = $doc_obj->get_top_section();
426 my $prevpos = ( $i == 0 ? 0 : $imgs->{$fplist[$i - 1]}{'pos'});
427 my $nextpos = ( $i >= ($nimgs -1) ? -1 : $imgs->{$fplist[$i + 1]}{'pos'} );
428
429 $self->extract_image_info($imgtag, $filepath, $textref, $doc_obj, $section, $tndir, $prevpos, $nextpos);
430 $processor->process($doc_obj);
431 $numdocs++;
432 $i++;
433 }
434 return $numdocs;
435 } else {
436 print $outhandle "HTMLImagePlugin: No images from $file indexed\n"
437 if ( $self->{'verbosity'} > 2 );
438 return 1;
439 }
440
441}
442
443# for every valid image tag
444# 1. extract related text and image metadata
445# 2. add this as document meta-data
446# 3. add assoc image(s) as files
447#
448sub extract_image_info {
449 my $self = shift (@_);
450 my ($tag, $id, $textref, $doc_obj, $section, $tndir, $prevpos, $nextpos) = (@_);
451 my ($filename, $orig_fp, $fn, $ext, $reltext, $relreltext, $crcid, $imgs,
452 $thumbfp, $pagetitle, $alttext, $filepath, $aggr);
453
454 my $imagick_cmd = "\"".&util::get_perl_exec()."\" -S gs-magick.pl";
455
456 $aggr = $self->{'aggressiveness'};
457 $imgs = \%{$self->{'imglist'}};
458 $filepath = $imgs->{$id}{'relpath'};
459 ($filename) = $filepath =~ /([^\/\\]+)$/s;
460 ($orig_fp) = "$self->{'base_path'}/$filepath";
461 $orig_fp =~ tr/+/ /;
462 $orig_fp =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg; # translate %2E to space, etc
463 $orig_fp =~ s/\\/\//g;
464 $filepath = "$self->{'htpath'}/$filepath";
465 my ($onlyfn) = $filename =~ /([^\\\/]*)$/;
466 ($fn, $ext) = $onlyfn =~ /(.*)\.(.*)/;
467 $fn = lc $fn; $ext = lc $ext;
468 ($reltext) = "<tr><td>GifComment</td><td>" . `$imagick_cmd identify $filepath -ping -format "%c"` . "</td></tr>\n"
469 if ($ext eq "gif");
470 $reltext .= "<tr><td>FilePath</td><td>$orig_fp</td></tr>\n";
471
472 if ($ENV{'GSDLOS'} =~ /^windows$/i) {
473 $crcid = "$fn.$ext." . $self->{'next_crcid'}++;
474 } else {
475 ($crcid) = `cksum $filepath` =~ /^(\d+)/;
476 }
477
478 $thumbfp = "$tndir/tn_$crcid.jpg";
479 `$imagick_cmd convert -flatten -filter Hanning $self->{'convert_params'} -geometry "$self->{'thumb_size'}x$self->{'thumb_size'}>" $filepath $thumbfp` unless -e $thumbfp;
480 if ( ! (-e $thumbfp) ) {
481 print STDERR "HTMLImagePlugin: 'convert' failed. Check ImageMagicK binaries are installed and working correctly\n"; return 0;
482 }
483
484 # shove in full text (tag stripped or unstripped) if settings require it
485 if ( $aggr == 10) {
486 $reltext = "<tr><td>AllPage</td><td>" . $$textref . "</td><tr>\n"; # level 10 (all text, verbatim)
487 } else {
488 $pagetitle = $self->get_meta_value("title", $textref);
489 ($alttext) = $tag =~ /\salt\s*=\s*(?:\"|\')(.+?)(?:\"|\')/is;
490 if ( defined($alttext) && length($alttext) > 1) {
491 $reltext .= "<tr><td>ALTtext</td><td>$alttext</td></tr>\n"; }
492 $reltext .= "<tr><td>SplitCapitalisation</td><td>" .
493 $self->split_filepath($orig_fp) . "</td></tr>\n";
494
495 # get caption/tag based near text (if appropriate)
496 if ( $aggr > 1 ) {
497 if ( $aggr >= 2 ) {
498 $reltext .=
499 $self->extract_caption_text($tag, $textref, $prevpos, $imgs->{$id}{'pos'}, $nextpos);
500 $relreltext = $reltext;
501 }
502 # repeat the filepath, alt-text, caption, etc
503 if ( $aggr == 8 ) {
504 $reltext .= $relreltext;
505 }
506 if ( $aggr >= 3 ) {
507 $reltext .=
508 $self->extract_near_text($tag, $textref, $prevpos, $imgs->{$id}{'pos'}, $nextpos);
509 }
510
511 # get page metadata (if appropriate)
512 if ( $aggr >= 6 || ( $aggr >= 2 &&
513 ( $self->{'images_indexed'} < 2 ||
514 ($self->{'smallpage'} == 1 && $self->{'images_indexed'} < 6 )))) {
515 $reltext .= $self->get_page_metadata($textref);
516 }
517 # textual references
518 if ( $aggr == 5 || $aggr >= 7) {
519 if ( length($relreltext) > ($self->{'caption_length'} * 2) ) {
520 $reltext .= $self->get_textrefs($relreltext, $textref, $prevpos, $imgs->{$id}{'pos'}, $nextpos); }
521 else {
522 $reltext .= $self->get_textrefs($reltext, $textref, $prevpos, $imgs->{$id}{'pos'}, $nextpos);
523 }
524 }
525 } # aggr > 1
526 } # aggr != 10
527
528 $doc_obj->set_OID($crcid);
529 $doc_obj->associate_file($thumbfp, "$fn.thumb.jpg", undef, $section);
530 $doc_obj->add_metadata($section, "OriginalFilename", $filename);
531 $doc_obj->add_metadata($section, "FilePath", $orig_fp);
532 $doc_obj->add_metadata($section, "Filename", $fn);
533 $doc_obj->add_metadata($section, "FileExt", $ext);
534 $doc_obj->add_metadata($section, "FileSize", $imgs->{$id}{'filesize'});
535 $doc_obj->add_metadata($section, "Width", $imgs->{$id}{'width'});
536 $doc_obj->add_metadata($section, "Height", $imgs->{$id}{'height'});
537 $doc_obj->add_metadata($section, "URL", "http://$orig_fp");
538 $doc_obj->add_metadata($section, "PageURL", $self->{'hturl'});
539 $doc_obj->add_metadata($section, "PageTitle", $pagetitle);
540 $doc_obj->add_metadata($section, "ThumbURL",
541 "_httpprefix_/collect/[collection]/index/assoc/[assocfilepath]/$fn.thumb.jpg");
542 $doc_obj->add_metadata($section, "FileFormat", "W3Img");
543
544 if ( $self->{'document_text'} ) {
545 $doc_obj->add_utf8_text($section, "<table border=1>\n$reltext</table>");
546 } else {
547 $doc_obj->add_metadata($section, "ImageText", "<table border=1>\n$reltext</table>\n");
548 }
549
550 if ( $self->{'index_pages'} ) {
551 my ($cache_url) = "_httpdoc_&d=" . $self->{'htdoc_obj'}->get_OID();
552 if ( $imgs->{$id}{'anchored'} ) {
553 my $a_name = $id;
554 $a_name =~ s/[\/\\\:\&]/_/g;
555 $cache_url .= "#gsdl_$a_name" ;
556 }
557 $doc_obj->add_utf8_metadata($section, "CachePageURL", $cache_url);
558 }
559 if ( ! $self->{'no_cache_images'} ) {
560 $onlyfn = lc $onlyfn;
561 $doc_obj->associate_file($filepath, $onlyfn, undef, $section);
562 $doc_obj->add_utf8_metadata($section, "CacheURL",
563 "_httpprefix_/collect/[collection]/index/assoc/[assocfilepath]/$onlyfn");
564 }
565 return 1;
566}
567
568sub get_page_metadata {
569 my ($self, $textref) = (@_);
570 my (@rval);
571 $rval[0] = $self->get_meta_value("title", $textref);
572 $rval[1] = $self->get_meta_value("keywords", $textref);
573 $rval[2] = $self->get_meta_value("description", $textref);
574 $rval[3] = $self->{'filename'};
575
576 return wantarray ? @rval : "<tr><td>PageMeta</td><td>@rval</td></tr>\n" ;
577}
578
579# turns LargeCatFish into Large,Cat,Fish so MG sees the separate words
580sub split_filepath {
581 my ($self, $filepath) = (@_);
582 my (@words) = $filepath =~ /([A-Z][a-z]+)/g;
583 return join(',', @words);
584}
585
586# finds and extracts sentences
587# that seem to be on the same topic
588# as other related text (correlations)
589# and textual references (e.g. in figure 3 ...)
590sub get_textrefs {
591 my ($self, $reltext, $textref, $prevpos, $pos, $nextpos) = (@_);
592 my ($maxtext, $mintext, $startpos, $context_size, $context);
593
594 my (@relwords, @refwords, %sentences, @pagemeta);
595
596 # extract larger context
597 $maxtext = $self->{'max_near_text'};
598 $startpos = $pos - ($maxtext * 4);
599 $context_size = $maxtext*10;
600 if ($startpos < $prevpos ) { $startpos = $prevpos }
601 if ($nextpos != -1 && $context_size > ( $nextpos - $startpos )) { $context_size = ($nextpos - $startpos) }
602 $context = substr ( $$textref, $startpos, $context_size );
603 $context =~ s/<.*?>//gs;
604 $context =~ s/^.*>(.*)/$1/gs;
605 $context =~ s/(.*)<.*$/$1/gs;
606
607 # get page meta-data (if not already included)
608 if ( $self->{'aggressiveness'} == 5 && ! $self->{'smallpage'} ) {
609 @pagemeta = $self->get_page_metadata($textref);
610 foreach my $value ( @pagemeta ) {
611 $context .= "$value."; # make each into psuedo-sentence
612 }
613 }
614
615 # TODO: this list is not exhaustive
616 @refwords = ( '(?:is|are)? ?(?:show(?:s|n)|demonstrate(?:d|s)|explains|features) (?:in|by|below|above|here)',
617 '(?:see)? (?:figure|table)? (?:below|above)');
618
619 # extract general references
620 foreach my $rw ( @refwords ) {
621 while ( $context =~ /[\.\?\!\,](.*?$rw\W.*?[\.\?\!\,])/ig ) {
622 my $sentence = $1;
623 $sentence =~ s/\s+/ /g;
624 $sentences{$sentence}+=2;
625 }
626 }
627 # extract specific (figure, table) references by number
628 my ($fignum) = $context =~ /[\.\?\!].*?(?:figure|table)s?[\-\_\ \.](\d+\w*)\W.*?[\.\?\!]/ig;
629 if ( $fignum ) {
630 foreach my $rw ( @refwords ) {
631 while ( $context =~ /[\.\?\!](.*?(figure|table)[\-\_\ \.]$fignum\W.*?[\.\?\!])/ig ) {
632 my $sentence = $1;
633 $sentence =~ s/\s+/ /g;
634 $sentences{$sentence}+=4;
635 }
636 }
637 }
638
639 # sentences with occurances of important words
640 @relwords = $reltext =~ /([a-zA-Z]{4,})/g; # take out small words
641 foreach my $word ( @relwords ) {
642 if ( $self->{'stopwords'}{$word} ) { next } # skip stop words
643 while ( $context =~ /([^\.\?\!]*?$word\W.*?[\.\?\!])/ig ) {
644 my $sentence = $1;
645 $sentence =~ s/\s+/ /g;
646 $sentences{$sentence}++;
647 }
648 }
649 foreach my $sentence ( keys %sentences ) {
650 if ($sentences{$sentence} < $self->{'textrefs_threshold'}) {
651 delete $sentences{$sentence};
652 }
653 }
654 my ($rval) = join "<br>\n", (keys %sentences);
655 if ( $rval && length($rval) > 5 ) {
656 return ( "<tr><td>TextualReferences</td><td>" . $rval . "</td></tr>\n") }
657 else { return "" }
658}
659
660# handles caption extraction
661# calling the extractor with different
662# tags and choosing the best candidate caption
663sub extract_caption_text {
664 my ($self, $tag, $textref, $prevpos, $pos, $nextpos) = (@_);
665 my (@neartext, $len, $hdelim, $mintext, $goodlen,
666 $startpos, $context, $context_size);
667
668 $mintext = $self->{'min_near_text'};
669 $goodlen = $self->{'caption_length'};
670
671 # extract a context to extract near text from (faster)
672 $context_size = $self->{'max_near_text'}*3;
673 $startpos = $pos - ($context_size / 2);
674 if ($startpos < $prevpos ) { $startpos = $prevpos }
675 if ($nextpos != -1 && $context_size > ( $nextpos - $startpos ))
676 { $context_size = ($nextpos - $startpos) }
677
678 $context = substr ( $$textref, $startpos, $context_size );
679 $context =~ s/<!--.*?-->//gs;
680 $context =~ s/^.*-->(.*)/$1/gs;
681 $context =~ s/(.*)<!--.*$/$1/gs;
682
683 # try stepping through markup delimiter sets
684 # and selecting the best one
685 foreach $hdelim ( @{ $self->{'cdelims'} } ) {
686 @neartext = $self->extract_caption($tag, $hdelim, \$context);
687 $len = length(join("", @neartext));
688 last if ($len >= $mintext && $len <= $goodlen);
689 }
690 # reject if well over reasonable length
691 if ( $len > $goodlen ) {
692 @neartext = [];
693 }
694 $neartext[0] = " " if (! defined $neartext[0]);
695 $neartext[1] = " " if (! defined $neartext[1]);
696 return "<tr><td>Caption</td><td>" . (join ",", @neartext) . "</td></tr>\n"; # TODO: the | is for testing purposes
697} # end extract_caption_text
698
699# the previous section header often gives a bit
700# of context to the section that the image is
701# in (invariably the header is before/above the image)
702# so extract the text of the closest header above the image
703#
704# this fn just gets all the headers above the image, within the context window
705sub get_prev_header {
706 my ($self, $pos, $textref) = (@_);
707 my ($rhtext);
708 while ( $$textref =~ /<h\d>(.*?)<\/h\d>/sig ) {
709 # only headers before image
710 if ((pos $$textref) < $pos) {
711 $rhtext .= "$1, ";
712 }
713 }
714 if ( $rhtext ) { return "Header($rhtext)" }
715 else { return "" }
716}
717
718# not the most robust tag stripping
719# regexps (see perl.com FAQ) but good enough
720#
721# used by caption & tag-based near text algorithms
722sub strip_tags {
723 my ( $self, $value ) = @_;
724 if ( ! defined($value) ) { $value = "" } # handle nulls
725 else {
726 $value =~ s/<.*?>//gs; # strip all html tags
727 $value =~ s/\s+/\ /g; # remove extra whitespace
728 $value =~ s/\&\w+\;//g; # remove &nbsp; etc
729 }
730 return $value;
731}
732
733# uses the given tag(s) to identify
734# the caption near to the image
735# (below, above or both below and above)
736sub extract_caption {
737 my ($self, $tag, $bound_tag, $contextref) = (@_);
738 my (@nt, $n, $etag, $gotcap);
739 return ("", "") if ( ! ($$contextref =~ /\Q$tag/) );
740
741 $nt[0] = $`;
742 $nt[1] = $';
743 $gotcap = 0;
744
745 # look before the image for a boundary tag
746 ($etag, $nt[0]) = $nt[0] =~ /<($bound_tag)[\s]?.*?>(.*?)$/is;
747 # if bound_tag too far from the image, then prob not caption
748 # (note: have to allow for tags, so multiply by 3
749 if ( $etag && length($nt[0]) < ($self->{'caption_length'} * 3) ) {
750 if ( $nt[0] =~ /<\/$etag>/si ) {
751 # the whole caption is above the image: <tag>text</tag><img>
752 ($nt[0]) =~ /<(?:$etag)[\s]?.*?>(.*?)<\/$etag>/is;
753 $nt[0] = $self->strip_tags($nt[0]);
754 if ( length($nt[0]) > $self->{'min_near_text'} ) {
755 $gotcap = 1;
756 $nt[1] = "";
757 }
758
759 } elsif ( $nt[1] =~ /<\/$etag>/si) {
760 # the caption tag covers image: <tag>text?<img>text?</tag>
761 ($nt[1]) = $nt[1] =~ /(.*?)<\/$etag>/si;
762 $nt[0] = $self->strip_tags($nt[0] . $nt[1]);
763 if ( length($nt[0]) > $self->{'min_near_text'} ) {
764 $gotcap = 2;
765 $nt[1] = "";
766 }
767 }
768 }
769 # else try below the image
770 if ( ! $gotcap ) {
771 # the caption is after the image: <img><tag>text</tag>
772 ($etag, $nt[1]) = $nt[1] =~ /^.*?<($bound_tag)[\s]?.*?>(.*)/is;
773 if ( $etag && $nt[1] =~ /<\/$etag>/s) {
774 ($nt[1]) = $nt[1] =~ /(.*?)<\/$etag>/si;
775 $gotcap = 3;
776 $nt[0] = "";
777 $nt[1] = $self->strip_tags($nt[1]);
778 }
779 }
780 if ( ! $gotcap ) { $nt[0] = $nt[1] = "" }
781 else {
782 # strip part-tags
783 $nt[0] =~ s/^.*>//s;
784 $nt[1] =~ s/<.*$//s;
785 }
786 my ($type);
787 if ( $gotcap == 0 ) { return ("nocaption", "") }
788 elsif ( $gotcap == 1 ) { $type = "captionabove:" }
789 elsif ( $gotcap == 2 ) { $type = "captioncovering:" }
790 elsif ( $gotcap == 3 ) { $type = "captionbelow:" }
791 return ($type, $nt[0], $nt[1]);
792}
793
794# tag-based near text
795#
796# tries different tag sets
797# and chooses the best one
798sub extract_near_text {
799 my ($self, $tag, $textref, $prevpos, $pos, $nextpos) = (@_);
800 my (@neartext, $len, $hdelim, $maxtext, $mintext, $goodlen,
801 @bestlen, @best, $startpos, $context, $context_size,
802 $dist, $bdist, $best1, $i, $nt);
803 $bestlen[0] = $bestlen[1] = 0; $bestlen[2] = $bdist = 999999;
804 $best[0] = $best[1] = $best[2] = "";
805 $maxtext = $self->{'max_near_text'};
806 $mintext = $self->{'min_near_text'};
807 $goodlen = $self->{'neartext_length'};
808
809 # extract a context to extract near text from (faster)
810 $context_size = $maxtext*4;
811 $startpos = $pos - ($context_size / 2);
812 if ($startpos < $prevpos ) { $startpos = $prevpos }
813 if ($nextpos != -1 && $context_size > ( $nextpos - $startpos ))
814 { $context_size = ($nextpos - $startpos) }
815 $context = substr ( $$textref, $startpos, $context_size );
816 $context =~ s/<!--.*?-->//gs;
817 $context =~ s/^.*-->(.*)/$1/gs;
818 $context =~ s/(.*)<!--.*$/$1/gs;
819
820 # try stepping through markup delimiter sets
821 # and selecting the best one
822 foreach $hdelim ( @{ $self->{'delims'} } ) {
823 @neartext = $self->extract_tagged_neartext($tag, $hdelim, \$context);
824 $nt = join("", @neartext);
825 $len = length($nt);
826 # Priorities:
827 # 1. Greater than mintext
828 # 2. Less than maxtext
829 # 3. Closest to goodlen
830 if ( $len <= $goodlen && $len > $bestlen[0] ) {
831 $bestlen[0] = $len;
832 $best[0] = $hdelim;
833 } elsif ( $len >= $maxtext && $len < $bestlen[2] ) {
834 $bestlen[2] = $len;
835 $best[2] = $hdelim;
836 } elsif ( $len >= $bestlen[0] && $len <= $bestlen[2] ) {
837 $dist = abs($goodlen - $len);
838 if ( $dist < $bdist ) {
839 $bestlen[1] = $len;
840 $best[1] = $hdelim;
841 $bdist = $dist;
842 }
843 }
844 }
845 $best1 = 2;
846 foreach $i ( 0..2 ) {
847 if ( $bestlen[$i] == 999999 ) { $bestlen[$i] = 0 }
848 $dist = abs($goodlen - $bestlen[$i]);
849 if ( $bestlen[$i] > $mintext && $dist <= $bdist ) {
850 $best1 = $i;
851 $bdist = $dist;
852 }
853 }
854 @neartext = $self->extract_tagged_neartext($tag, $best[$best1], \$context);
855 if ( $bestlen[$best1] > $maxtext ) {
856 # truncate on word boundary if too much text
857 my $hmax = $maxtext / 2;
858 ($neartext[0]) = $neartext[0] =~ /([^\s]*.{1,$hmax})$/s;
859 ($neartext[1]) = $neartext[1] =~ /^(.{1,$hmax}[^\s]*)/s;
860 } elsif ( $bestlen[$best1] < $mintext ) {
861 # use plain text extraction if tags failed (e.g. usable tag outside context)
862 print {$self->{'outhandle'}} "HTMLImagePlugin: Fallback to plain-text extraction for $tag\n"
863 if $self->{'verbosity'} > 2;
864 $neartext[0] = "<tr><td>RawNeartext</td><td>" . $self->extract_raw_neartext($tag, $textref) . "</td></tr>";
865 $neartext[1] = "";
866 }
867 # get previous header if available
868 $neartext[0] .= "<br>\n" .
869 $self->get_prev_header($pos, \$context) if ( $self->{'aggressiveness'} >= 4 );
870 $neartext[0] = " " if (! defined $neartext[0]);
871 $neartext[1] = " " if (! defined $neartext[1]);
872
873 return "<tr><td>NearText</td><td>" . (join "|", @neartext) . "</td></tr>\n"; # TODO: the | is for testing purposes
874} # end extract_near_text
875
876# actually captures tag-based
877# near-text given a tag set
878sub extract_tagged_neartext {
879 my ($self, $tag, $bound_tag, $textref) = (@_);
880 return "" if ( ! ($$textref =~ /\Q$tag/) );
881 my (@nt, $delim, $pre_tag, $n);
882 $nt[0] = $`;
883 $nt[1] = $';
884
885 # get text after previous image tag
886 $nt[0] =~ s/.*<($bound_tag)[^>]*>(.*)/$2/is; # get rid of preceding text
887 if (defined($1)) { $delim = $1 }
888 $pre_tag = $bound_tag;
889
890 if (defined($delim)) {
891 # we want to try and use the end tag of the previous delimiter
892 # (put it on the front of the list)
893 $pre_tag =~ s/(^|\|)($delim)($|\|)//i; # take it out
894 $pre_tag =~ s/\|\|/\|/i; # replace || with |
895 $pre_tag = $delim . "|" . $pre_tag; # put it on the front
896 }
897
898 # get text before next image tag
899 $nt[1] =~ s/<\/?(?:$pre_tag)[^>]*>.*//is; # get rid of stuff after first delimiter
900
901 # process related text
902 for $n (0..1) {
903 if ( defined($nt[$n]) ) {
904 $nt[$n] =~ s/<.*?>//gs; # strip all html tags
905 $nt[$n] =~ s/\s+/\ /gs; # remove extra whitespace
906 $nt[$n] =~ s/\&\w+\;//sg; # remove &nbsp; etc
907 # strip part-tags
908 if ( $n == 0 ) { $nt[0] =~ s/^.*>//s }
909 if ( $n == 1 ) { $nt[1] =~ s/<.*$//s }
910 } else { $nt[$n] = ""; } # handle nulls
911 }
912 return @nt;
913}
914
915# this function is fall-back
916# if tags aren't suitable.
917#
918# extracts a fixed length of characters
919# either side of image tag (on word boundary)
920sub extract_raw_neartext {
921 my ($self, $tag, $textref) = (@_);
922 my ($rawtext, $startpos, $fp);
923 my $imgs = \%{$self->{'imglist'}};
924 ($fp) = $tag =~ /([\w\\\/]+\.(?:gif|jpe?g|png))/is;
925 if (! $fp) { return " " };
926 # if the cached, plain-text version isn't there, then create it
927 $self->init_plaintext($textref) unless defined($self->{'plaintext'});
928
929 # take the closest maxtext/2 characters
930 # either side of the tag (by word boundary)
931 return "" if ( ! exists $imgs->{$fp}{'rawpos'} );
932 $startpos = $imgs->{$fp}{'rawpos'} - (($self->{'max_near_text'} / 2) + 20);
933 if ( $startpos < 0 ) { $startpos = 0 }
934 $rawtext = substr $self->{'plaintext'}, $startpos, $self->{'max_near_text'} + 20;
935 $rawtext =~ s/\s\s/ /g;
936
937 return $rawtext;
938}
939
940# init plaintext variable for HTML-stripped version
941# (for full text index/raw assoc text extraction)
942sub init_plaintext {
943 my ($self, $textref) = (@_);
944 my ($page, $fp);
945 my $imgs = \%{$self->{'imglist'}};
946 $page = $$textref; # make a copy of original
947
948 # strip tags around image filenames so they don't get zapped
949 $page =~ s/<\w+\s+.*?([\w\/\\]+\.(?:gif|jpe?g|png))[^>]*>/\"$1\"/gsi;
950 $page =~ s/<.*?>//gs;
951 $page =~ s/&nbsp;/ /gs;
952 $page =~ s/&amp;/&/gs; #TODO: more &zzz; replacements (except &lt;, $gt;)
953
954 # get positions and strip images
955 while ( $page =~ /([^\s\'\"]+\.(jpe?g|gif|png))/ig ) {
956 $fp = $1;
957 if ( $imgs->{$fp}{'exists'} ) {
958 $imgs->{$fp}{'rawpos'} = pos $page;
959 }
960 $page =~ s/\"$fp\"//gs;
961 }
962 $self->{'plaintext'} = $page;
963}
964
965# finds and filters images based on size
966# (dimensions, height, filesize) and existence
967#
968# looks for image filenames (.jpg, .gif, etc)
969# and checks for existence on disk
970# (hence supports most JavaScript images)
971sub get_img_list {
972 my $self = shift (@_);
973 my ($textref) = (@_);
974 my ($filepath, $relpath, $abspath, $pos, $num, $width, $height, $filesize);
975 my $imgs = \%{$self->{'imglist'}};
976 while ( $$textref =~ /([^\s\'\"]+\.(jpe?g|gif|png))/ig ) {
977 $filepath = $1;
978 $pos = pos $$textref;
979 next if ( $imgs->{$filepath}{'relpath'} );
980 $relpath = $filepath;
981 $relpath =~ s/^http\:\/\///; # remove http:// in case we have mirrored it
982 $relpath =~ s/\\/\//g; # replace \ with /
983 $relpath =~ s/^\.\///s; # make "./filepath" into "filepath"
984 $imgs->{$filepath}{'relpath'} = $relpath;
985 $abspath = "$self->{'htpath'}/$relpath";
986
987 if (! -e $abspath) { next }
988
989 # can't modify real filepath var because it
990 # then can't be located in the page for tag recognition later
991 my $imagick_cmd = "\"".&util::get_perl_exec()."\" -S gs-magick.pl";
992 ($width, $height) =
993 `$imagick_cmd identify $abspath -ping -format "%wx%h"` =~ /^(\d*)x(\d*)$/m;
994 if (! ($width && $height)) {
995 print STDERR "HTMLImagePlugin: ($abspath) 'identify' failed. Check ImageMagicK binaries are installed and working correctly\n"; next;
996 }
997 $filesize = (-s $abspath);
998 if ( $filesize >= $self->{'min_size'}
999 && ( $width >= $self->{'min_width'} )
1000 && ( $height >= $self->{'min_height'} ) ) {
1001
1002 $imgs->{$filepath}{'exists'} = 1;
1003 $imgs->{$filepath}{'pos'} = $pos;
1004 $imgs->{$filepath}{'width'} = $width;
1005 $imgs->{$filepath}{'height'} = $height;
1006 $imgs->{$filepath}{'filesize'} = $filesize;
1007 } else {
1008 print {$self->{'outhandle'}} "HTMLImagePlugin: skipping $self->{'base_path'}/$relpath: $filesize, $width x $height\n"
1009 if $self->{'verbosity'} > 2;
1010 }
1011 }
1012 $num = 0;
1013 foreach my $i ( keys %{$imgs} ) {
1014 if ( $imgs->{$i}{'pos'} ) {
1015 $num++;
1016 } else { delete $imgs->{$i} }
1017 }
1018 return $num;
1019}
1020
1021# make the text available to the read function
1022# by making it an object variable
1023sub read_file {
1024 my ($self, $filename, $encoding, $language, $textref) = @_;
1025 $self->SUPER::read_file($filename, $encoding, $language, $textref);
1026
1027 # if HTMLplug has run through, then it will
1028 # have replaced references so we have to
1029 # make a copy of the text before processing
1030 if ( $self->{'index_pages'} ) {
1031 $self->{'text'} = $$textref;
1032 $self->{'textref'} = \($self->{'text'});
1033 } else {
1034 $self->{'textref'} = $textref;
1035 }
1036 $self->{'plaintext'} = undef;
1037}
1038
1039# HTMLPlugin only extracts meta-data if it is specified in plugin options
1040# hence a special function to do it here
1041sub get_meta_value {
1042 my ($self, $name, $textref) = @_;
1043 my ($value);
1044 $name = lc $name;
1045 if ($name eq "title") {
1046 ($value) = $$textref =~ /<title>(.*?)<\/title>/is
1047 } else {
1048 my $qm = "(?:\"|\')";
1049 ($value) = $$textref =~ /<meta name\s*=\s*$qm?$name$qm?\s+content\s*=\s*$qm?(.*?)$qm?\s*>/is
1050 }
1051 $value = "" unless $value;
1052 return $value;
1053}
1054
1055# make filename an anchor reference
1056# so we can go straight to the image
1057# within the cached version of the source page
1058# (augment's HTMLPlugin sub)
1059sub replace_images {
1060 my $self = shift (@_);
1061 my ($front, $link, $back, $base_dir,
1062 $file, $doc_obj, $section) = @_;
1063 $link =~ s/\"//g;
1064 my ($a_name) = $link;
1065 $a_name =~ s/[\/\\\:\&]/_/g;
1066 # keep a list so we don't repeat the same anchor
1067 if ( ! $self->{'imglist'}{$link}{'anchored'} ) {
1068 $front = "<a name=\"gsdl_$a_name\">$front";
1069 $back = "$back</a>";
1070 $self->{'imglist'}{$link}{'anchored'} = 1;
1071 }
1072 return $self->SUPER::replace_images($front, $link, $back, $base_dir,
1073 $file, $doc_obj, $section);
1074}
1075
10761;
Note: See TracBrowser for help on using the repository browser.