Perl and PDF - YAPC::EU 2015 Presentation

Zentech Innovatiosn Pvt. Ltd.
Hyderabad
Telangana
India
© 2010 Zentech Innovations Pvt. Ltd.
Page 1
Perl and PDF
Prabhakar Somu
psomu@yahoo.com
Zentech Innovations Pvt. Ltd.
Hyderabad, India
September 2, 2015

Hyderabad
Telangana
India
Page 2
What we do
Transactional Communications
• Our business is primarily involved in
creation, printing, dispatching,
emailing and web-presenting
transactional/financial documents.
• Large volume PDF document
production
• Variable Data, Statement
composition

Hyderabad
Telangana
India
Page 3
A brief history of PDF (Portable
Document Format)
• Created by Adobe in 1993
• Compact, device independent, cross
platform
• A subset of Postscript page description
language
• Font embedding/replacement/sub-setting
• Compression and structured (reusable)
component storage

Hyderabad
Telangana
India
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A brief history of PDF contd…
• Versions:
– PDF 1.0 (Acrobat 1.0) – 1992
– PDF 1.1 (Acrobat 2.0) – 1994
– PDF 1.2 (Acrobat 3.0) – 1996
– PDF 1.3 (Acrobat 4.0) – 1999
– PDF 1.4 (Acrobat 5.0) – 2001
– PDF 1.5 (Acrobat 6.0) – 2003
– PDF 1.6 (Acrobat 7.0) – 2005
– PDF 1.7 (Acrobat 8.0) - 2006

Hyderabad
Telangana
India
Page 5
Postscript and PDF
• Postscript is a Page Description Language
and a programming language
• Has to be interpreted and Imaged (ripped)
on a device
• Device specific
• PDF contains a subset of Postscript
elements without any control flow
• Self-Contained

Hyderabad
Telangana
India
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Postscript and PDF
• A page in Postscript has to be ‘ripped’ and
imaged before a subsequent page can be
imaged (graphics state needs to be
maintained)
• Any page of a PDF file can be displayed
without needing to display earlier pages
• Device independent
• Self contained, fonts embedded, identical
rendering on all platforms

Hyderabad
Telangana
India
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Postscript and PDF
• Ideal in a Web environment – as any page
can be displayed at any time
• PDF files can be streamed
• Compact, reusable components within a
PDF file
• Identical rendering across devices
• No interpretation required in PDF

Hyderabad
Telangana
India
Page 8
Perl and PDF
• PDF::Create
• CAM::PDF
• PDF::API2
• PDF::API3
• PDF::Extract
• PDF::Xtract
• PDF::GetImages
• PDF::Template
• PDF::Reuse
• PDF::ReportWriter
• PDF::Table
• PDF::Parse
• PDF::Report
Several modules on CPAN

Hyderabad
Telangana
India
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Perl and PDF (contd.)
• PDF::Core
• PDF::OCR2
• Fuse::PDF
• PDF::Burst
• PDF::Haru
• PDF::Imposition
• PDF::EasyPDF
• Image::Magick::Thumbn
ail::PDF
• PDF::Labels
• PDF::Tk
• PDF::Reuse::Barcode
• deletepdfpage.pl
• PDF::Boxer
• PDFlib

Hyderabad
Telangana
India
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Special Mention
• PDF::API2
• PDF::API3
• CAM::PDF
• PDF::Haru
• Quite extensive

Hyderabad
Telangana
India
Page 11
Approximate categorization of Perl
PDF Modules
• Creation
• Repurposing
• Extraction
• Miscellaneous

Hyderabad
Telangana
India
Page 12
Creation
Repurposing
Content
Extraction
Miscellaneous
PDF::Create
PDF::Create
PDF::Table
PDF::Report
PDF::Template
PDF::ReportWriter
PDF::Haru
PDF::EasyPDF
PDF::Labels
PDF::Boxer
PDF::API2
PDF::API3
CAM::PDF
PDF::Extract
PDF::Xtract
PDF::GetImages
PDF::OCR
PDF::OCR2
PDF::Reuse
PDF::Burst
Image::Magick::
Thumbnail::PDF
PDF::Tk
PDF::Parse
PDF::Core
Fuse::PDF
pdflib
PDF::Reuse::Barc
ode

Hyderabad
Telangana
India
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PDF Modules - Creation
• PDF::Create
• PDF::Table
• PDF::Report
• PDF::Template
• PDF::ReportWriter
• PDF::Haru
• PDF::EasyPDF
• PDF::Labels
• PDF::Boxer

Hyderabad
Telangana
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PDF Modules - Repurposing
• PDF::Reuse
• PDF::Burst
• PDF::Imposition
• Image::Magick::Thumbnail::PDF
• PDF::Tk

Hyderabad
Telangana
India
Page 15
PDF Modules – Content Extraction
• PDF::Extract
• PDF::Xtract
• PDF::OCR
• PDF::OCR2
• PDF::GetImages

Hyderabad
Telangana
India
Page 16
PDF Modules - Miscellaneous
• PDF::Parse
• PDF::Core
• Fuse::PDF

Hyderabad
Telangana
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PDF Modules – General Purpose
• PDF::API2
• PDF::API3
• CAM::PDF
• pdflib

Hyderabad
Telangana
India
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Will be using PDFLib as a way of
showing various aspects
• From pdflib.com
• Commercial as well as open source
• Comprehensive, cross-platform, wide support for
versions, image formats, color spaces, text
rendering, graphics etc.
• PDFlib (for creating PDF files)
• PDI (for repurposing existing PDF files)
• TET (for extracting text)
• pCos (for accessing non-page data)
• PLOP (for linearizing PDFs)

Hyderabad
Telangana
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Creating PDF files - PDFLib
use PDFlib::PDFlib 8.0;
my $p = new PDFlib::PDFlib;
$p->set_parameter(“compatibility” , “1.7”);
$p->set_parameter(“license” , “XYX);
$p->begin_document(“output.pdf” , “optimize”);
$p->begin_page_ext(“width=A4.width height=A4.height”, “”);
# Create content here
$p->end_page_ext( “” );
$p->end_document( “” );

Hyderabad
Telangana
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Creating linearized PDF files -
PDFLib
use PDFlib::PDFlib 8.0;
my $p = new PDFlib::PDFlib;
$p->set_parameter(“compatibility” , “1.7”);
$p->set_parameter(“license” , “XYX);
$p->begin_document(“output.pdf” , “optimize linearize”);
$p->begin_page_ext(“width=A4.width height=A4.height”, “”);
# Create content here

Hyderabad
Telangana
India
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Creating PDF files - PDFLib
Several Options when creating a document and page:
Document Options
• password, document open actions, openmode (bookmarks,
thumbnails etc.), optimize,
• permissions (noprint, nomodify etc.)
Page Options
• Specify artbox, cropbox etc.
• Width and height
• XMP Metadata
• and many more

Hyderabad
Telangana
India
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Fonts and PDF
my $font_handle1 = $p->load_font(“Courier” , “” , “” );
my $font_handle2 = $p->load_font(“Calibri” , “” , “” );
• Searches for fonts in the resource path
(set_parameter)
• Unicode fonts

Hyderabad
Telangana
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Laying out Text
$p->setfont( $font_handle1, “32”);
$p->fittextline( “Your Text Here” , $xpos, $ypos, “” );
$p->fittextline( “More text” , $xpos2, $ypos2, “” );

Hyderabad
Telangana
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Placing Images
my $image_handle =
$p->load_image( “auto” , $image_file, “options”);
$p->fit_image( $image_handle, $x, $y, “options” );
• Many image formats such as JPG, TIF, BMP are
automatically identified and loaded
• Multi-Page TIF files are handled as well
• Black and White, Grayscale, Color images handled
• Color profiles and many other parameters can be
set
• Several positioning and fitting options

Hyderabad
Telangana
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Barcodes in PDF files
• A number of barcode types are possible
• Two methods of placing barcodes:
– Font Based
– Image Based
• In Font based method, load a barcode font (like a
QRCode font) and place text in that font
• In the image based method, load an image (of the
barcode) and place the image on a page.
PDF-SamplesPunjabi.pdf
PDF-SamplesAssame.pdf

Hyderabad
Telangana
India
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Metadata in PDF files (XMP
Metadata)
• Concept of non-printable metadata in PDF
files
• Some information such as Author, Date of
Creation, Key Words can be placed using
set_parameter call
• More extensive arbitrary data can be
injected usingthe ‘XMP Metadata’ channel
• Possible in TIFF, JPEG files as well

Hyderabad
Telangana
India
Page 27
Metadata in PDF files (XMP
Metadata)
• XMP data can be placed at the document,
page or image level
PDF-Samplessimple.txt
$p->begin_document( $output_pdf,
“metadata={filename={simple.txt}}”);

Hyderabad
Telangana
India
Page 28
Named Destinations – Navigating to
specific pages in a PDF
$p->begin_page_ext(“width=A4.width
height=A4.height”, “”);
$p->add_nameddest( “Page1” , “options” );
file:///C:/Output.pdf#nameddest=Page1

Hyderabad
Telangana
India
Page 29
Javascript in PDF files
• Javascript can be embedded in PDF files
• Actions can be tied to Javascript code
• For example, when a page is displayed
(opened) – execute a function
PDF-Samplesbarcode_field.pdf
PDF-Samplesbarcode_field.pl

Hyderabad
Telangana
India
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PDF/A
• Special version of PDF meant for long term
archival and retrieval
• Many interactive elements not allowed
• No Hyperlinks, forms etc.
• Guaranteed to be supported by Adobe
• Applications in Library archival systems,
legal document archival and retrieval etc.
where long term compatibility of documents
is crucial
• PDFLib can create such documents

Hyderabad
Telangana
India
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Types of Page Boundaries
http://www.prepressure.com/pdf/basics/page
-boxes
• Media Box – Specifies the width and height
of the media (paper size)
• Crop Box – Are to which page contents are
clipped (for display)
• Trim Box – Intended dimensions of the
finished page (by default = Crop Box)
• All of these can be specified in PDFLib as
options in begin_document

Hyderabad
Telangana
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Bookmarks, Thumbnails
• Bookmarks and Thumbnails can be created using
PDFLib
$p->begin_page_ext(“width=A4.width
height=A4.height”, “”);
$p->create_bookmark(“Bookmark Display Name” ,
“{type fitwindow}” );
$p->add_thumbnail( $thumbnail_image_handle);

Hyderabad
Telangana
India
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Controlling how a PDF file is first
displayed in Adobe (Acrobat or
Viewer)
$p->begin_document( “output.pdf”, “viewer-
preferences=centerwindow”);
$p->begin_document( “output.pdf”, “viewer-
preferences=duplex”);

Hyderabad
Telangana
India
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Dealing with encrypted PDF files
• Specify password in begin_document

Hyderabad
Telangana
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Disabling ability to Print,
Cut/Copy/Save etc.
$p->begin_document( “output.pdf”,
“action=noprint nomodify”);

Hyderabad
Telangana
India
Page 36
Repurposing existing PDF files using
PDI
• An existing PDF file can be read in and
content placed as is in an output
my $input_doc_handle = $p->open_pdi( $input_file, “”, 0);
$p->begin_document( $output_file , “” );
$p->begin_page_ext( $width, $height);
my $page_handle = $p->open_pdi_page( $input_doc_handle,
$page_no);
$p->fit_pdi_page( $page_handle, 0 , 0, $boxsize);
$p->close_pdi_page( “” );

Hyderabad
Telangana
India
Page 37
PDF Files with embedded images
• Each page can have an image and nothing
else
• Scanned images are typically combined into
such PDF files
• Many options and possibilities to compress
such images in a PDF file (from Adobe
Acrobat as well as PDFLib)
• Text and other content can be overlaid on
such files as well using PDFLib’s graphic
operators

Hyderabad
Telangana
India
Page 38
Converting PDF pages into other
formats
• ImageMagick and PerlMagick
• Convert individual pages to images
• PDF::GetImages

Hyderabad
Telangana
India
Page 39
Text Extraction with TET
Using the Text Extraction Tool (TET), text in a PDF file
can be intelligently and reliably extracted
tet.exe –tetopt —pageopt=“{{200 750 400 755}}” –xml
line
(find text in the box 200,750,400,755 output as XML
and recognize lines)
• A perl binding for TET exists
• Note that this is not performing an ‘OCR’ option – it
is intelligently querying the PDF nodes

Hyderabad
Telangana
India
Page 40
Non Printable data extraction using
pCOS
Using the pCOS tool, non printable data such as
number of pages, XMP metadata,
Author/Creator/Date information can be extracted.
• Extract/check for bookmarks
• Extract ICC Profiles
• Check for security problems

Hyderabad
Telangana
India
Page 41
Important take-aways from this
presentation
• Too many modules on CPAN (quite confusing)
• None are complete (in my humble opinion)
• Commercial or open source equivalent of PDFLib
(and associated libraries such as TET, pCOS) make
an ideal toolset.
• A lot more than text and graphics is possible with
PDF files

Hyderabad
Telangana
India
Page 42
Prabhakar Somu
+91 97048 71236 (Mobile India)
(908) 500 5902 (Mobile US)
Email: somup@zensys.com
Thanks for your attention!

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