root/gsdl/trunk/perllib/plugins/PagedImagePlugin.pm @ 16384

Revision 16384, 20.6 KB (checked in by kjdon, 12 years ago)

global block pass: new block_hash arg to read and metadata_read. Also added a comment about whether we need to convert the filename to utf8 before calling generate_images (I am not sure)

  • Property svn:executable set to *
  • Property svn:keywords set to Author Date Id Revision
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1###########################################################################
2#
3# PagedImagePlugin.pm -- plugin for sets of images and OCR text that
4#  make up a document
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) 1999 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# PagedImagePlugin
28# processes sequences of images, with optional OCR text
29#
30# This plugin takes *.item files, which contain metadata and lists of image
31# files, and produces a document containing sections, one for each page.
32# The files should be named something.item, then you can have more than one
33# book in a directory. You will need to create these files, one for each
34# document/book.
35#
36#There are two formats for the item files: a plain text format, and an xml
37#format. You can use either format, and can have both formats in the same
38#collection if you like. If you use the plain format, you must not start the
39#file off with <PagedDocument>
40
41#### PLAIN FORMAT
42# The format of the xxx.item file is as follows:
43# The first lines contain any metadata for the whole document
44# <metadata-name>metadata-value
45# eg.
46# <Title>Snail farming
47# <Date>19230102
48# Then comes a list of pages, one page per line, each line has the format
49#
50# pagenum:imagefile:textfile:r
51#
52# page num and imagefile are required. pagenum is used for the Title
53# of the section, and in the display is shown as page <pagenum>.
54# imagefile is the image for the page. textfile is an optional text
55# file containing the OCR (or any) text for the page - this gets added
56# as the text for the section. r is optional, and signals that the image
57# should be rotated 180deg. Eg use this if the image has been made upside down.
58# So an example item file looks like:
59# <Title>Snail farming
60# <Date>19960403
61# 1:p1.gif:p1.txt:
62# 2:p2.gif::
63# 3:p3.gif:p3.txt:
64# 3b:p3b.gif:p3b.txt:r
65# The second page has no text, the fourth page is a back page, and
66# should be rotated.
67#
68
69#### XML FORMAT
70# The xml format looks like the following
71#<PagedDocument>
72#<Metadata name="Title">The Title of the entire document</Metadata>
73#<Page pagenum="1" imgfile="xxx.jpg" txtfile="yyy.txt">
74#<Metadata name="Title">The Title of this page</Metadata>
75#</Page>
76#... more pages
77#</PagedDocument>
78#PagedDocument contains a list of Pages, Metadata and PageGroups. Any metadata
79#that is not inside another tag will belong to the document.
80#Each Page has a pagenum (not used at the moment), an imgfile and/or a txtfile.
81#These are both optional - if neither is used, the section will have no content.
82#Pages can also have metadata associated with them.
83#PageGroups can be introduced at any point - they can contain Metadata and Pages and other PageGroups. They are used to introduce hierarchical structure into the document.
84#For example
85#<PagedDocument>
86#<PageGroup>
87#<Page>
88#<Page>
89#</PageGroup>
90#<Page>
91#</PagedDocument>
92#would generate a structure like
93#X
94#--X
95#  --X
96#  --X
97#--X
98#PageGroup tags can also have imgfile/textfile metadata if you like - this way they get some content themselves.
99
100#Currently the XML structure doesn't work very well with the paged document type, unless you use numerical Titles for each section.
101#There is still a bit of work to do on this format:
102#* enable other text file types, eg html, pdf etc
103#* make the document paging work properly
104#* add pagenum as Title unless a Title is present?
105
106# All the supplemetary image amd text files should be in the same folder as
107# the .item file.
108#
109# To display the images instead of the document text, you can use [srcicon]
110# in the DocumentText format statement.
111# For example,
112#
113# format DocumentText "<center><table width=_pagewidth_><tr><td>[srcicon]</td></tr></table></center>"
114#
115# To have it create thumbnail size images, use the '-create_thumbnail' option.
116# To have it create medium size images for display, use the '-create_screenview'
117# option. As usual, running
118# 'perl -S pluginfo.pl PagedImagePlugin' will list all the options.
119
120# If you want the resulting documents to be presented with a table of
121# contents, use '-documenttype hierarchy', otherwise they will have
122# next and previous arrows, and a goto page X box.
123
124# If you have used -create_screenview, you can also use [screenicon] in the format
125# statement to display the smaller image.  Here is an example  that switches
126# between the two:
127#
128# format DocumentText "<center><table width=_pagewidth_><tr><td>{If}{_cgiargp_ eq full,<a href='_httpdocument_&d=_cgiargd_&p=small'>Switch to small version.</a>,<a href='_httpdocument_&d=_cgiargd_&p=full'>Switch to fullsize version</a>}</td></tr><tr><td>{If}{_cgiargp_ eq full,<a href='_httpdocument_&d=_cgiargd_&p=small' title='Switch to small version'>[srcicon]</a>,<a href='_httpdocument_&d=_cgiargd_&p=full' title='Switch to fullsize version'>[screenicon]</a>}</td></tr></table></center>"
129#
130# Additional metadata can be added into the .item files, alternatively you can
131# use normal metadata.xml files, with the name of the xxx.item file as the
132# FileName (only for document level metadata).
133
134package PagedImagePlugin;
135
136use ReadXMLFile;
137use ReadTextFile;
138use ImageConverter;
139
140use strict;
141no strict 'refs'; # allow filehandles to be variables and viceversa
142
143sub BEGIN {
144    @PagedImagePlugin::ISA = ('ReadXMLFile', 'ReadTextFile', 'ImageConverter');
145}
146
147my $type_list =
148    [ { 'name' => "paged",
149        'desc' => "{PagedImagePlugin.documenttype.paged}" },
150      { 'name' => "hierarchy",
151        'desc' => "{PagedImagePlugin.documenttype.hierarchy}" } ];
152
153my $arguments =
154    [ { 'name' => "process_exp",
155    'desc' => "{BasePlugin.process_exp}",
156    'type' => "string",
157    'deft' => &get_default_process_exp(),
158    'reqd' => "no" },
159      { 'name' => "block_exp",
160    'desc' => "{BasePlugin.block_exp}",
161    'type' => "string",
162    'deft' => &get_default_block_exp(),
163    'reqd' => "no" },
164      { 'name' => "title_sub",
165    'desc' => "{HTMLPlugin.title_sub}",
166    'type' => "string",
167    'deft' => "" },
168      { 'name' => "headerpage",
169    'desc' => "{PagedImagePlugin.headerpage}",
170    'type' => "flag",
171    'reqd' => "no" },
172      { 'name' => "documenttype",
173    'desc' => "{PagedImagePlugin.documenttype}",
174    'type' => "enum",
175    'list' => $type_list,
176    'deft' => "paged",
177    'reqd' => "no" } ];
178
179
180my $options = { 'name'     => "PagedImagePlugin",
181        'desc'     => "{PagedImagePlugin.desc}",
182        'abstract' => "no",
183        'inherits' => "yes",
184        'args'     => $arguments };
185
186sub new {
187    my ($class) = shift (@_);
188    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
189    push(@$pluginlist, $class);
190
191    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
192    push(@{$hashArgOptLists->{"OptList"}},$options);
193   
194    new ImageConverter($pluginlist, $inputargs, $hashArgOptLists);
195    new ReadTextFile($pluginlist, $inputargs, $hashArgOptLists, 1);
196    my $self = new ReadXMLFile($pluginlist, $inputargs, $hashArgOptLists);
197   
198    return bless $self, $class;
199}
200
201
202sub init {
203    my $self = shift (@_);
204    my ($verbosity, $outhandle, $failhandle) = @_;
205
206    $self->SUPER::init(@_);
207    $self->ImageConverter::init();
208}
209
210sub get_default_process_exp {
211    my $self = shift (@_);
212
213    return q^\.item$^;
214}
215
216sub get_doctype {
217    my $self = shift(@_);
218   
219    return "PagedDocument";
220}
221
222
223# want to block everything except the .item ones
224# but instead we will block images and txt files
225sub get_default_block_exp {
226    my $self = shift (@_);
227   
228    return q^(?i)(\.jpe?g|\.gif|\.png|\.tif?f|\.te?xt|\.html?|~)$^
229}
230
231# we want to use BasePlugin's read, not ReadXMLFile's
232sub read
233{
234    my $self = shift (@_);
235    $self->BasePlugin::read(@_);
236}
237
238
239sub read_into_doc_obj {
240    my $self = shift (@_);
241    my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs, $total_count, $gli) = @_;
242    my $outhandle = $self->{'outhandle'};
243   
244    my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);
245
246    print $outhandle "PagedImagePlugin processing \"$filename_full_path\"\n"
247    if $self->{'verbosity'} > 1;
248    print STDERR "<Processing n='$file' p='PagedImagePlugin'>\n" if ($gli);
249   
250   
251    # here we need to decide if we have an old text .item file, or a new xml
252    # .item file
253    my $xml_version = $self->is_xml_item_file($filename_full_path);
254
255    $self->tidy_item_file($filename_full_path);
256   
257    my $doc_obj;
258    if ($xml_version) {
259    # careful checking needed here!! are we using local xml handlers or super ones
260    $self->ReadXMLFile::read($pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs, $total_count, $gli);
261    $doc_obj = $self->{'doc_obj'};
262    } else {
263    my ($dir);
264    ($dir, $file) = $filename_full_path =~ /^(.*?)([^\/\\]*)$/;
265
266    #process the .item file
267    $doc_obj = $self->process_item($filename_full_path, $dir, $file, $processor);
268   
269    }
270
271    my $section = $doc_obj->get_top_section();
272       
273    $doc_obj->add_utf8_metadata($section, "Plugin", "$self->{'plugin_type'}");
274    $doc_obj->add_metadata($section, "FileFormat", "PagedImage");
275
276    # include any metadata passed in from previous plugins
277    # note that this metadata is associated with the top level section
278    $self->add_associated_files($doc_obj, $filename_full_path);
279    $self->extra_metadata ($doc_obj, $section, $metadata);
280    $self->auto_extract_metadata ($doc_obj);
281
282    # if we haven't found any Title so far, assign one
283    $self->title_fallback($doc_obj,$section,$filename_no_path);
284
285    $self->add_OID($doc_obj);
286    return (1,$doc_obj);
287}
288
289# for now, the test is if the first non-empty line is <PagedDocument>, then its xml
290sub is_xml_item_file {
291    my $self = shift(@_);
292    my ($filename) = @_;
293
294    my $xml_version = 0;
295    open (ITEMFILE, $filename) || die "couldn't open $filename\n";
296   
297    my $line = "";
298    my $num = 0;
299    $line = <ITEMFILE>;
300    while ($line !~ /\w/) {
301    $line = <ITEMFILE>;
302    }
303    chomp $line;
304    if ($line =~ /<PagedDocument/) {
305    $xml_version = 1;
306    }
307    close ITEMFILE;
308    return $xml_version;
309}
310
311sub tidy_item_file {
312    my $self = shift(@_);
313    my ($filename) = @_;
314
315    open (ITEMFILE, $filename) || die "couldn't open $filename\n";
316    my $backup_filename = "backup.item";
317    open (BACKUP,">$backup_filename")|| die "couldn't write to $backup_filename\n";
318    my $line = "";
319    $line = <ITEMFILE>;
320    $line =~ s/^\xEF\xBB\xBF//; # strip BOM
321    $line =~ s/\x0B+//ig;
322    $line =~ s/&/&amp;/g;
323    print BACKUP ($line);
324    #Tidy up the item file some metadata title contains \vt-vertical tab
325    while ($line = <ITEMFILE>) {
326    $line =~ s/\x0B+//ig;
327    $line =~ s/&/&amp;/g;
328    print BACKUP ($line);
329    }
330    close ITEMFILE;
331    close BACKUP;
332    &File::Copy::copy ($backup_filename, $filename);
333    &util::rm($backup_filename);
334
335}
336
337sub rotate_image {
338    my $self = shift (@_);
339    my ($filename_full_path) = @_;
340   
341    my ($this_filetype) = $filename_full_path =~ /\.([^\.]*)$/;
342    my $result = $self->convert($filename_full_path, $this_filetype, "-rotate 180", "ROTATE");
343    my ($new_filename) = ($result =~ /=>(.*\.$this_filetype)/);
344    if (-e "$new_filename") {
345    return $new_filename;
346    }
347    # somethings gone wrong
348    return $filename_full_path;
349
350}
351
352sub process_image {
353    my $self = shift(@_);
354    my ($filename_full_path, $filename_no_path, $doc_obj, $section, $rotate) = @_;
355    # do rotation
356    if ($rotate eq "r") {
357    # check the filenames
358    return 0 if ($filename_no_path eq "" || !-f $filename_full_path);
359
360    # we get a new temporary file which is rotated
361    $filename_full_path = $self->rotate_image($filename_full_path);
362    }
363   
364    # do generate images
365    my $result = 0;
366    if ($self->{'image_conversion_available'} == 1) {
367    # do we need to convert $filename_no_path to utf8? We are already reading in from a file, what encoding is it in???
368    $result = $self->generate_images($filename_full_path, $filename_no_path, $doc_obj, $section);
369    }
370    #overwrite one set in ImageConverter
371    $doc_obj->set_metadata_element ($section, "FileFormat", "PagedImage");
372    return $result;
373}
374
375
376sub xml_start_tag {
377    my $self = shift(@_);
378    my ($expat, $element) = @_;
379    $self->{'element'} = $element;
380   
381    my $doc_obj = $self->{'doc_obj'};
382    if ($element eq "PagedDocument") {
383    $self->{'current_section'} = $doc_obj->get_top_section();
384    } elsif ($element eq "PageGroup" || $element eq "Page") {
385    # create a new section as a child
386    $self->{'current_section'} = $doc_obj->insert_section($doc_obj->get_end_child($self->{'current_section'}));
387    $self->{'num_pages'}++;
388    # assign pagenum as  what??
389    my $pagenum = $_{'pagenum'}; #TODO!!
390    if (defined $pagenum) {
391        $doc_obj->set_utf8_metadata_element($self->{'current_section'}, 'PageNum', $pagenum);
392    }
393    my ($imgfile) = $_{'imgfile'};
394    if (defined $imgfile) {
395        $self->process_image($self->{'base_dir'}.$imgfile, $imgfile, $doc_obj, $self->{'current_section'});
396    }
397    my ($txtfile) = $_{'txtfile'};
398    if (defined($txtfile)&& $txtfile ne "") {
399        $self->process_text ($self->{'base_dir'}.$txtfile, $txtfile, $doc_obj, $self->{'current_section'});
400    } else {
401        $self->add_dummy_text($doc_obj, $self->{'current_section'});
402    }
403    } elsif ($element eq "Metadata") {
404    $self->{'metadata_name'} = $_{'name'};
405    }
406}
407
408sub xml_end_tag {
409    my $self = shift(@_);
410    my ($expat, $element) = @_;
411   
412    my $doc_obj = $self->{'doc_obj'};
413    if ($element eq "Page" || $element eq "PageGroup") {
414    # if Title hasn't been assigned, set PageNum as Title
415    if (!defined $doc_obj->get_metadata_element ($self->{'current_section'}, "Title") && defined $doc_obj->get_metadata_element ($self->{'current_section'}, "PageNum" )) {
416        $doc_obj->add_utf8_metadata ($self->{'current_section'}, "Title", $doc_obj->get_metadata_element ($self->{'current_section'}, "PageNum" ));
417    }
418    # move the current section back to the parent
419    $self->{'current_section'} = $doc_obj->get_parent_section($self->{'current_section'});
420    } elsif ($element eq "Metadata") {
421   
422    $doc_obj->add_utf8_metadata ($self->{'current_section'}, $self->{'metadata_name'}, $self->{'metadata_value'});
423    $self->{'metadata_name'} = "";
424    $self->{'metadata_value'} = "";
425
426    }
427    # otherwise we ignore the end tag
428}
429
430
431sub xml_text {
432    my $self = shift(@_);
433    my ($expat) = @_;
434
435    if ($self->{'element'} eq "Metadata" && $self->{'metadata_name'}) {
436    $self->{'metadata_value'} .= $_;
437    }
438}
439
440sub xml_doctype {
441}
442
443sub open_document {
444    my $self = shift(@_);
445   
446    # create a new document
447    $self->{'doc_obj'} = new doc ($self->{'filename'}, "indexed_doc");
448    # TODO is file filenmae_no_path??
449    $self->set_initial_doc_fields($self->{'doc_obj'}, $self->{'file'}, $self->{'processor'});
450
451    my ($dir, $file) = $self->{'filename'} =~ /^(.*?)([^\/\\]*)$/;
452    $self->{'base_dir'} = $dir;
453    $self->{'num_pages'} = 0;
454
455}
456
457sub close_document {
458    my $self = shift(@_);
459    my $doc_obj = $self->{'doc_obj'};
460   
461    # add numpages metadata
462    $doc_obj->set_utf8_metadata_element ($doc_obj->get_top_section(), 'NumPages', $self->{'num_pages'});
463
464   
465}
466
467
468sub set_initial_doc_fields {
469    my $self = shift(@_);
470    my ($doc_obj, $filename_no_path, $processor) = @_;
471
472    $doc_obj->set_OIDtype ($processor->{'OIDtype'}, $processor->{'OIDmetadata'});
473    my $topsection = $doc_obj->get_top_section();
474
475    if ($self->{'documenttype'} eq 'paged') {
476    # set the gsdlthistype metadata to Paged - this ensures this document will
477    # be treated as a Paged doc, even if Titles are not numeric
478    $doc_obj->set_utf8_metadata_element ($topsection, "gsdlthistype", "Paged");
479    } else {
480    $doc_obj->set_utf8_metadata_element ($topsection, "gsdlthistype", "Hierarchy");
481    }
482
483    $self->set_Source_metadata($doc_obj, $filename_no_path);
484   
485    # if we want a header page, we need to add some text into the top section, otherwise this section will become invisible
486    if ($self->{'headerpage'}) {
487    $self->add_dummy_text($doc_obj, $topsection);
488    }
489
490
491}
492
493
494sub process_item {
495    my $self = shift (@_);
496    my ($filename_full_path, $dir, $filename_no_path, $processor) = @_;
497
498    my $doc_obj = new doc ($filename_full_path, "indexed_doc");
499    $self->set_initial_doc_fields($doc_obj, $filename_no_path, $processor);
500    my $topsection = $doc_obj->get_top_section();
501    open (ITEMFILE, $filename_full_path) || die "couldn't open $filename_full_path\n";
502    my $line = "";
503    my $num = 0;
504    while (defined ($line = <ITEMFILE>)) {
505    next unless $line =~ /\w/;
506    chomp $line;
507    next if $line =~ /^#/; # ignore comment lines
508    if ($line =~ /^<([^>]*)>\s*(.*?)\s*$/) {
509        $doc_obj->set_utf8_metadata_element ($topsection, $1, $2);
510        #$meta->{$1} = $2;
511    } else {
512        $num++;
513        # line should be like page:imagefilename:textfilename:r - the r is optional -> means rotate the image 180 deg
514        $line =~ s/^\s+//; #remove space at the front
515        $line =~ s/\s+$//; #remove space at the end
516        my ($pagenum, $imgname, $txtname, $rotate) = split /:/, $line;
517       
518        # create a new section for each image file
519        my $cursection = $doc_obj->insert_section($doc_obj->get_end_child($topsection));
520        # the page number becomes the Title
521        $doc_obj->set_utf8_metadata_element($cursection, 'Title', $pagenum);
522     
523        # process the image for this page if there is one
524        if (defined $imgname && $imgname ne "") {
525        my $result1 = $self->process_image($dir.$imgname, $imgname, $doc_obj, $cursection, $rotate);
526       
527        if (!defined $result1)
528        {
529            print "PagedImagePlugin: couldn't process image \"$dir.$imgname\" for item \"$filename_full_path\"\n";
530        }
531        }
532        # process the text file if one is there
533        if (defined $txtname && $txtname ne "") {
534        my $result2 = $self->process_text ($dir.$txtname, $txtname, $doc_obj, $cursection);
535               
536        if (!defined $result2) {
537            print "PagedImagePlugin: couldn't process text file \"$dir.$txtname\" for item \"$filename_full_path\"\n";
538            $self->add_dummy_text($doc_obj, $cursection);
539        }
540        } else {
541        # otherwise add in some dummy text
542        $self->add_dummy_text($doc_obj, $cursection);
543        }
544    }
545    }
546   
547    close ITEMFILE;
548
549    # add numpages metadata
550    $doc_obj->set_utf8_metadata_element ($topsection, 'NumPages', "$num");
551    return $doc_obj;
552}
553
554sub process_text {
555    my $self = shift (@_);
556    my ($filename_full_path, $file, $doc_obj, $cursection) = @_;
557   
558    # check that the text file exists!!
559    if (!-f $filename_full_path) {
560    print "PagedImagePlugin: ERROR: File $filename_full_path does not exist, skipping\n";
561    return 0;
562    }
563
564    # Do encoding stuff
565    my ($language, $encoding) = $self->textcat_get_language_encoding ($filename_full_path);
566
567    my $text="";
568    &ReadTextFile::read_file($self, $filename_full_path, $encoding, $language, \$text);
569    if (!length ($text)) {
570    # It's a bit unusual but not out of the question to have no text, so just give a warning
571        print "PagedImagePlugin: WARNING: $filename_full_path contains no text\n";
572    }
573
574    # we need to escape the escape character, or else mg will convert into
575    # eg literal newlines, instead of leaving the text as '\n'
576    $text =~ s/\\/\\\\/g; # macro language
577    $text =~ s/_/\\_/g; # macro language
578
579
580    if ($text =~ m/<html.*?>\s*<head.*?>.*<\/head>\s*<body.*?>(.*)<\/body>\s*<\/html>\s*$/s) {
581    # looks like HTML input
582    # no need to escape < and > or put in <pre> tags
583
584    $text = $1;
585
586    # insert preformat tags and add text to document object
587    $doc_obj->add_utf8_text($cursection, "$text");
588    }
589    else {
590    $text =~ s/</&lt;/g;
591    $text =~ s/>/&gt;/g;
592
593    # insert preformat tags and add text to document object
594    $doc_obj->add_utf8_text($cursection, "<pre>\n$text\n</pre>");
595    }
596
597   
598    return 1;
599}
600
601
602sub clean_up_after_doc_obj_processing {
603    my $self = shift(@_);
604   
605    $self->ImageConverter::clean_up_temporary_files();
606}
607
6081;
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