Buggy PDF Files, should we try to fix them?

Aug 16 2010

Very frequently we come across malformed PDF files. These files view just fine in Acrobat(r) Reader but fail to load with our tools and other third-party tools. This has become a real nightmare for PDF developers. From the customer’s view, the PDF file opens with Acrobat Reader, so it has to be a perfectly valid PDF and the customer does not care about what happens in the background.

Here is one example of a situation that we encountered very recently. The PDF file is generated from a well known scanner brand whose manufacturer would probably sue us just for mentionning their name. At the end of every PDF file, there is a cross reference table that tells the PDF consumer (reader or processing engine) where the various parts of the PDF are located within the file. To locate the cross reference table, the consumer looks for the “startxref” entry towards the end of the file. Here is what this entry looks like in our problematic PDF file:


The PDF consumer goes to the location 101806 in the file and expects to find a cross reference table that looks like this:

0 153
0000000000 65535 f
0000101369 00000 n

Again, this table provides the location of each object within the PDF file. In the case of our buggy PDF, location 101806 points to a random location in the file that contains:


So how is Acrobat Reader opening the file? It actually displays a very brief warning when opening the file and then rebuilds the whole xref table by going through all the file. On most systems with Acrobat Reader already launched, the warning is so brief that users do not even notice it. There are many inconveniences and risks in doing this:

  1. If the file is fairly complex, rebuilding the xref table is time consuming and might fail for compressed objects.
  2. PDF files can be incrementally modified, which means the original information remains intact and new objects added to modify, add or delete things that existed in the original PDF. This is done by creating an updated cross reference table. A funny but dangerous thing might happen: The viewer might retrieve the old PDF data rather than the updated one, so if the user had deleted something from the PDF, the viewer might actually display the deleted information.
  3. The startxref might be valid, but the xref table itself contain invalid entries. So the problem does not appear when opening the file but only later on when scrolling through the document.

Explaining all this to a customer usually results in negative reactions such as “why do we care when the file was generated by this multi-billion-dollar corporation and is processed correctly by Adobe?” So what is the solution? Try to convince Adobe that invalid files should be rejected, or at least really warn the users? But then, some of Adobe’s own files have similar issues, so how could they explain this warning appearing on their own PDFs?

This is only one example of badly formatted PDFs that we come across. Our position has always been to inform our customers, try to fix the invalid PDF and generate a warning to the developer. But this has been going on for way too long with no end in sight.

Dany Amiouny is the CTO for Amyuni Technologies

Amyuni named in 2010 SD Times 100

Jun 23 2010

Amyuni Technologies Blog
Amyuni Technologies has been named in the SD Times 100 under the Components & Libraries category.

The SD Times 100 recognizes top innovators and leaders in the software development industry.


Alex Furness is the Marketing Director for Amyuni Technologies

PDF Courier: Moving Beyond Email to Send Files

May 14 2010

Amyuni Technologies Blog
In our previous post we looked at how Manage File Tools (MFT) have become useful alternatives to send files compared to FTP and email applications. In this article we shall look at how PDF Courier can guarantee the delivery of your important documents and how it can prevent your attachments from being blocked by email Spam filters.

Over the years, Spam emails have dramatically increased. This is due to the proliferation of private and corporate personal information online. The result, are individuals unnecessarily and aggressively targeted by unsolicited emails, usually from unknown sources. As a result, many legitimate emails never make it to their intended destinations, either because they are inadvertently blocked by Spam filters or because recipients overlooked them. It’s true that there are “email acknowledgment” features senders can use to illicit reception, but often, these features are ignored by document receivers.

In addition, emails with attachments are especially prone to being excluded by Spam filters. Most email servers today are configured to scrutinize anything that looks suspicious. Whereas years ago executables and unfamiliar file extensions were the prime targets, today’s blocked attachments include images, PDFs, and even common file formats.

Three Options: One Purpose

By contrast PDF Courier features three different options that individuals can use to send their documents without email server restraints: A Web-based interface, a standalone desktop application, and a Microsoft Outlook® plug-in. All three share the same functionalities and all three have secure, guaranteed delivery capabilities to bypass email Spam filters.

For example, when a user sends an email with an attachment (Figure 1) using the Web interface, PDF Courier will remove and temporarily keep an email’s attachment. The recipient will then receive the email and a prompt to go safely download the attachment from PDF Courier. Once the attachment has been downloaded the sender gets a notification message from PDF Courier to inform them of a successful reception.

Figure 1: PDF Courier Sending Email


In an upcoming post, we shall see how the PDF Courier’s Web easy-to-use functionalities can also be integrated directly into Microsoft Outlook.

Franc Gagnon is the technical copywriter for Amyuni Technologies

PDF Courier: Managed File Transfer Made Easy

May 06 2010

Amyuni Technologies Blog
Sending files to and from organizations is part of our corporate communication. What originally began decades ago as simple file transfers between research and government campuses, has become part of business interactions around the world. FTP was the original workhorse that enabled us to send files, but as network capacities grew, so did our need to send larger and larger files.

Soon FTP carried complex documents, large images, and even multimedia. As a result, file transferring softwares and email applications became popular alternatives to FTP, but their popularity also came with a price. Security issues similar to those that plagued FTP often found their way into many file transferring softwares. And even though email applications were more secure than their file transferring counterparts, they too experienced problems, especially concerning privacy.

Inspired from FTP, Only Better

It wasn’t long before software developers recognized the need to provide end-users with tools that functioned like FTP, (but with better security) and also included notification options commonly found in email applications. The answer became what is known today as File Transfer (MFT) tools. MFT tools refer to a family of applications that enable end-users to send, track, and manage file transfers in and out of organizations.

Amyuni Technologies recognized the benefit of MFT tools and as a result, developed the PDF Courier; a simple and secure MFT tool to help users send and track their documents. With just a few options and configurations, the PDF Courier keeps file transfers simple without compromising security.

In our upcoming posts we shall explore some of the PDF Courier key features such as how it can:

  • Guarantee the delivery of your important documents and emails.
  • Prevent your documents and attachments from being blocked by email SPAM filters.
  • Convert your documents into PDF prior to being sent.
  • Track your documents and make sure they are delivered and read using real-time status notifications.
  • Transfer and store large files and avoid the storage limitations often imposed by many email applications.
  • Preview your sent and stored documents online, without the need to download them.
  • Work directly from your Microsoft Outlook® application.
Franc Gagnon is the technical copywriter for Amyuni Technologies

PDF and JBIG2: Working With the Benefits of Both

Mar 24 2010

Amyuni Technologies Blog
Ever since the PDF’s payload began carrying images, file size quickly became an issue. As people began adding larger and larger images into their PDF it took longer to transmit these files and the space in which they were stored filled up faster. Luckily image compression technologies were never far behind to help alleviate these problems. One such technology is JBIG2, a bi-level (black/white) image compression format introduced by the Joint Bi-level Image Experts Group.

Unlike previous image compression formats (including its predecessor JBIG1) JBIG2 uses an intelligent algorithm to achieve its compression ratios. In short, the algorithm first searches for and recognizes similar groups of pixels within an image. Then, it creates symbols to represent common or repeated shapes it has found and stores them in a table. This lossless compression process does not affect image quality and the end results are documents that can be one quarter to one fifth of their original size.

To Whom Does JBIG2 Serve?

Government, judicial, and medical sectors are some examples of PDF-intensive work places where subtle implementations of the JBIG2 format in their work flows can help IT Managers reap noticeable cost saving benefits later on. Not only are PDF files that contain JBIG2 compressed information easier to send and share, but they are easier to store, they display rapidly online, and they are OCR ready.

The following table outlines some of JBIG2’s main features:

JBIG2 Feature: Benefit: Example:
Higher compression rates than its predecessors (e.g., JBIG1, TIFF G3, and G4). File size reduction capabilities up to 90% or higher. Reduction in storage space and transmission bandwidth. With JBIG2 compression, a 78 MB uncompressed 500-page PDF document, would see its file size drop to 12.7 MB. An equivalent TIFF file would be approx. 15.8 MB.
Lossy and lossless compression methods. Lossy yields a higher compression rate without any perceivable information loss. A pass to clean the document of dots and artifacts from a scanned document can help JBIG2 compression by coding more simple white areas.
The use of symbol dictionaries • For the compression of other images within the same document .
• Eventually one symbol dictionary could be used to recognize the text in the image. It contains the building blocks of a possible OCR procedure to help rebuild font information (if lost).
• Unique to one PDF document, a global JBIG2 stream can contain a dictionary of symbols used for all the pages of the document.
• Once the dictionary is built, software attempts to recognize letters and build legible text from them.
The use of arithmetic and Huffman coding schemes for bit representation. Huffman coding takes less page memory and has faster compression and decompression than arithmetic coding. However, arithmetic compression is slower, uses more memory but yields better compression results. JBIG2 can support the Huffman and the arithmetic coding algorithms for image structure information such as encoding schemes, references, indexes, sizes, offsets, and popular symbol identities.
ITU-T T.6 facsimile coding schemes and coding control functions for Group 4 facsimile functionalities which is activated by a MMR (Modified Modified READ (Relative Element Access Designate)) flag. Use of the latest facsimile logic for the compression of building block images. Any image leaf can be coded using MMR logic. In addition, a symbol in a dictionary or whole page can be found in the JBIG2 stream as a MMR image.
Stripped-page compression. JBIG2 can compress uninterrupted image flows. Under specific circumstances, if a scanner sends image information without a page cut, a JBIG2 stream can still take the data and compress it.
Most PDF viewers support reading JBIG2 (ver. 1.4 and higher). JBIG2 technology can be easily integrated into the PDF’s established technologies. Most of the PDF documents produced by high-end scanners with professional drivers are compressed with JBIG2 technologies.

JBIG2: Smaller Things are Easier to Handle

Amyuni Technologies has been carefully following the evolution of JBIG2 ever since the format became supported by PDF. Amyuni Technologies first included JBIG2 decoding (decompression) capabilities in their PDF Creator and PDF Converter products.

Now, with these products’ upcoming 4.5 releases, Amyuni Technologies extends their JBIG2 support to include its encoding (compression) capabilities in addition to OCR capabilities. Whether for PDF integration or publication and distribution purposes, end-users and developers will be able take advantage of JBIG2’s powerful black and white compression capabilities.

Dany Amiouny is the CTO for Amyuni Technologies

Injecting Intelligence into PDFs with XMP (Part 2)

Feb 22 2010

Amyuni Technologies Blog
In a previous article, we reviewed the benefits and uses of PDF metadata. Specifically, we looked at the emergence of XMP metadata as a potential standardization for metadata frameworks and at how it can help PDF developers store, exchange, track, and retrieve information. In this article we will explore the injection of custom XMP metadata tags into existing PDF/A documents.

PDF/A and XMP: Inevitable Convergence

In 2001, developers recognized the need to add their own customized XMP metadata tags to PDF documents. They understood that by adding their own information, they could make a document easier to retrieve and include data that would not change regardless of where or how it was processed.

However, the introduction of the PDF/A standard has challenged some developers and has forced them to rethink how they would incorporate their XML customizations, especially into PDF/A documents. They realized that although there were many ways to add custom XML tags, there were only a few ways to keep their new data valid without compromising the PDF/A’s format restrictions.

Because of the rising popularity of PDF/A, Amyuni Technologies saw the need to provide developers with a tool that would help them solve specific PDF challenges, such as working within the confines of ISO archiving standard. This tool is the PDF Analyzer.

PDF/A: Driving Archiving and Document Conformance

One example of inserting customized XML information into PDF/A documents is with ERP purchasing applications. Often, developers use these applications to generate invoices or purchase orders in PDF/A for archiving and retrieval purposes. Although these files already contain XMP metadata, additional information can be added to make these files more useful—extractable information from the text content itself.

Items such as P.O. numbers, contact details, or the names of sales persons, departments, authors, and projects are all valuable pieces of information developers can use to create reports and enhance document retrieval. Developers can automate PDF Analyzer to:

  • Verify the internal structure of incoming PDF/A purchase orders from an ERP application for PDF/A compliance and repair them if necessary (and possible).
  • Locate and extract specific text strings (names, addresses, dates, etc.) from the PDF/A documents and convert them into XML (Figure 1).

Figure 1: Using PDF Analyzer to Extract and Convert Text Strings


  • Take the XML and create customized XMP extension schemas.
  • Reinsert the new customized XMP extension schemas into the XMP streams of the PDF/A documents.
  • Resave the document PDF/A and still keep its adherence to the ISO specifications.

Figure 2 outlines how this automated text conversion process would operate, either for single or multiple PDF/A documents:

Figure 2: Text String to XMP Metadata Workflow


When companies implement PDF/A, it’s often because they have high volumes of documents that require archiving. Insurance companies, banks, medical institutions, and manufacturing companies are just some examples of where the PDF Analyzer’s automation and XMP customization capabilities can bring a higher degree of efficiency to their documentation workflows.

Learn more about PDF Analyzer at www.pdfanalyzer.com.

Franc Gagnon is the technical copywriter for Amyuni Technologies

Editing PDFs: What You See is Not Always What You Get

Jan 19 2010

Amyuni Technologies Blog
Many have surely asked: “Why can’t editing text in a PDF document be as simple as it is in a Word file?” Actually, the PDF’s inherent simplicity is the reason editing text can be challenging. Because despite the PDF’s evolution, its core design and purpose, the PDF was and will continue to be, a final presentation document exchange format.

Text: To a Viewer, It’s Just Code

The reason behind the PDF’s text-editing elusiveness is the fact that words and sentences in a PDF document aren’t really text. They are collections of objects commonly referred to as text elements. A text element and its corresponding code instruct a PDF-viewing application which characters to draw and how to draw them at certain positions on a page. For example, figure 1 below, outlines how the two words “Hello World!” would appear to a PDF viewer before being displayed on screen:

Figure 1: Partial Code View of “Hello World!” (bolded for emphasis)

Once a PDF viewer such as the Amyuni PDF Creator displays them on screen, they appear as two connected words in a small sentence (Figure 2):

Figure 2: Text Elements Displayed as Two Words

However if we enable the PDF Creator’s border-viewing options, we can see how the two words are in fact four separate text elements, each enclosed within their own outlined borders (Figure 3).

Figure 3: Text Elements Contained Within Borders

The borders are visual aids that PDF Creator can display to help users identify the positions of text elements on a page. We can reposition the text out of its normal “left to right” sentence flow (Figure 4), to demonstrate how it behaves more like separate elements.

Figure 4: Separation of Text Elements

Trying to Keep the Eggs in the Same Basket

Borders identify each text element and helps users see how many characters are contained within each of them. A text element’s borders and contents are both modifiable, however this is not without introducing potential inconveniences such as character shifts, font changes, and altered sentence structures, etc. Changing a text element (such as inserting or removing characters) is really changing its structure and it should be done selectively.

Does this mean that the PDF’s design is to blame for our inability to easily edit its content? No. Its design is the PDF’s raison d’être—to prevent changing the document. However, because people will always need to edit PDFs, there must be a way for them to do so more easily. As we shall see in an upcoming article, there are several ways users can improve the way they edit PDFs. That includes approaching the PDF editing process with a different mindset and using an Amyuni PDF tool such as the PDF Creator.

Franc Gagnon is the technical copywriter for Amyuni Technologies

Integrating Versatility and Speed Into Applications

Jan 18 2010

Amyuni Technologies Blog
From its humble beginnings as a document exchange format to its worldwide recognition as an open standard, the PDF has stood the test of time and is here to stay. Today, PDF integration can be found in everything from Web browsers, to document management systems, and long-term archiving practices, to name a few. As a result, developers have been (and will be) busy designing PDF technologies and integrating them into more and more applications.

PDF: It’s No Longer Just About Text

Developers who design ERP, BPM, or DMS applications, for example, need PDF integration that is easy, seamless, and affordable. Furthermore, they need PDF creating, editing, and converting functionalities that can be quickly accessed; either through a stand-alone product or through the integration of a few lines of code into their applications. These and many more PDF integration needs have been Amyuni Technologies’ fields of expertise for more than 10 years.

One Bundle: Many PDF Possibilities

With over a decade of PDF experience, Amyuni Technologies has produced reputable PDF tools designed with the developer in mind. One such tool is the Amyuni PDF Suite—composed of the Amyuni PDF Converter and the Amyuni PDF Creator.

The Amyuni PDF Converter is a printing tool that creates PDFs from any Microsoft® Windows® application. This Windows 7-certified printer driver enables developers to generate stable, well-structured PDF documents in a fraction of the time required by other tools. Conversion speed is crucial for applications that convert high volumes of documents in multi-threaded and 64-bit environments.

The Amyuni PDF Creator is a tool that enables developers to display, create, edit, and print PDF documents from any Microsoft Windows operating system. Powerful, stable, and easy to use, the Amyuni PDF Creator gives developers a high degree of control over PDF documents and their content.
Available for .NET and ActiveX development environments, the Amyuni PDF Suite’s versatility combines the industry’s fastest PDF conversion with powerful document creation and control capabilities.

File Exchange: It’s More Than Just the Format

The support of different file formats is another aspect of versatility. The Amyuni PDF Suite supports the compressed XRef table and PDF 1.7 formats and generates PDF/X-1 and PDF/X-3 documents  which ensures that developers always work with the latest file formats. Furthermore, with the Amyuni PDF Suite’s updated PDF/A engine, developers can produce PDF files that adhere to the  PDF/A standard for the long-term archiving of documents.

However, file support is more than just loading and creating documents that have different formats. File support is also about sending, receiving, and archiving documents using standards such as XMP metadata and the PDF/A archiving standard. Fortunately for developers, the Amyuni PDF Suite provides support for both. With the PDF Creator they can embed their own customized XMP metadata within PDF/A-1a and PDF/A-1b documents and still retain ISO format requirements.

In addition to various PDF file formats, the Amyuni PDF Suite also supports complex internal file structures such as layered documents. Developers can use the PDF Creator to load, display, and create layered PDFs. A layered PDF is a document that was originally generated by software with layer-generating capabilities such as AutoCAD® or Microsoft Visio®. The resulting PDF contains optional content (layers) that can be displayed or hidden by the reader.

Silverlight: Because PDF Is Not Just About Printing

Processing and generating different portable document formats is a developmental necessity, but what about their presentation? With today’s demand for online documentation, developers need to know they can display PDF content using the latest Web technologies. An example of one such technology is Microsoft’s Silverlight™. With the Amyuni PDF Suite, developers can integrate Silverlight-viewing functionalities into their applications with minimal code changes and export PDF files directly into XAML. Once in XAML, PDF content can be displayed directly from the Web page’s Silverlight controls.

The Amyuni PDF Advantage: It Starts from the Inside

The Amyuni PDF Suite offers many development benefits and one of these is its proprietary technology. Because the Amyuni PDF Suite does not rely on any external libraries (e.g., Ghostscript), developers are not required to license any external technologies to distribute applications that use integrated Amyuni products. This benefit means low-cost licensing options that are advantageous not only for developers but for large corporate distributions as well.

It’s no surprise Amyuni Technologies have been integrated into thousands of applications on millions of desktops worldwide, turning developers’ software requirements into reliable PDF solutions.

Franc Gagnon is the technical copywriter for Amyuni Technologies

Amyuni PDF Converter 4.0 Gets Windows 7 Logo Certification

Sep 17 2009

Amyuni Technologies Blog
Amyuni Technologies is pleased to announce that its PDF Converter has obtained the Windows 7 Logo Certification. End-users and developers can benefit from this certification by working with a printer driver that is not only up-to-date, but also features more security and performance.

What is a Microsoft Logo Certification?

A Microsoft Logo Certification is the recognition that a software product has undergone and satisfied all of testing requirements specified by Microsoft. For a printer driver, some of these tests include:

  • Verifying that the printer driver does not crash the operating system even under heavy stress.
  • Verifying that the printer driver can run multiple print jobs at the same time.
  • Verifying that the printer driver does not take up too many system resources (i.e., memory, GDI handles, etc).
  • Verifying that the printer driver is compatible with the new features of the Windows 7 operating system.
  • Verifying that the printer driver performs equally well under a 32- and 64-bit Windows 7 operating system.

If the printer driver successfully completes all of the tests, the Amyuni digital signature is applied to it and it becomes Microsoft-certified.

More Than Just Testing

A digital signature acknowledges more than the passage of rigorous software testing. Similar to a “time stamp”, a digital signature confirms the authenticity of a printer driver and indicates that it has not been altered since its testing by its creator(s), third-parties, or by malicious intent (viruses).

Developing With a Certified Printer Driver

Developing with the Amyuni PDF Converter is more than innovating with the latest Windows 7 technologies. Once it is embedded into a third-party product, developers can submit their application under the scrutiny of a Microsoft testing environment and (if it passes) receive its own Windows 7 certification. Such testing for a third-party product augments its Windows operating system compliance, compatibility, and credibility.

Custom Branding: Extending Product Recognition

Developers who already own a PDF Converter printer driver license can also take advantage of Amyuni’s custom branding option. Custom branding replaces Amyuni Technologies’ proprietary details from the printer driver’s Printing Preferences with those of the developer or vendor. Custom branding extends third-party product recognition and increases company visibility.

Learn more about our branding and certification features at: www.amyuni.com.

Franc Gagnon is the technical copywriter for Amyuni Technologies

Injecting Intelligence into PDFs with XMP (Part 1)

Sep 11 2009

Unlike the workflows that previously surrounded printed content, today’s workflows contain more changing variables, especially when it comes to documentation. Documents are created, repurposed, archived, retrieved, and even merged into others. In short – they encompass change. As a result, keeping an eye on change is an essential part of document management.

What is Metadata and Why Use it?

Metadata is descriptive information about data. It can be embedded into a PDF file (as XML) to help identify its contents or characteristics during its travels. Examples of metadata include: author names, document title, subject description, source type, etc.

Metadata can help manage change. When businesses integrate metadata into their work flows, they can better track their document life cycles and stay ahead of document changes more effectively. However, as businesses grow and integrate metadata, they often introduce:

  • Large amounts of unstructured metadata. For example, documents that are appended or merged with others acquire additional metadata along the way.
  • Different frameworks to address the problem of unstructured metadata. However, such frameworks hamper the efficiency of dissimilar systems to interchange or process information.

In and of itself, metadata is often used to address (short-term) document life cycles, especially within localized environments. However, if the volume and exchange of documents increases, so does the complexity of the corresponding metadata. Is there an alternative way to handle such document assets more effectively? This is where XMP attempts to position itself as a viable option.

What is XMP Metadata and Why Use it?

Introduced by Adobe in 2001, the Extensible Metadata Platform (XMP) is a labeling specification, based on the W3C Resource Description Framework (RDF). XMP provides a (cross-platform) format for creating, processing, and interchanging metadata.

Therefore XMP (metadata) is a type of metadata that adheres to specific standards that dictate how data is organized and accessed. XMP metadata can be embedded into PDF documents, HTML, SVG, XML files, and image formats such as JPEG, TIFF, PNG, GIF, etc.

Designed as a type of encapsulating framework, XMP can act as a bridge between different systems that need to exchange and use metadata. When it comes to documentation, embedding XMP metadata into PDFs improves their searchability and integration into existing work flows. In addition, long-term archiving standards such as PDF/A-1a and PDF/A-1b require the use of XMP to identify that their contents are PDF/A compliant.

Embedding Intelligence into PDFs

Documents become smart assets when they are accompanied with XMP metadata. Once data is embedded in a PDF file as an XML packet (Figure 1) it stays with the file so it can be recycled and repurposed across different platforms or content-management systems.

Figure 1: XMP Packet Within a PDF Object

Customizing XMP

Because embedding XMP metadata differs slightly for portable document formats, developers should already be familiar with the XMP framework specifications and also how to work with the right XMP-enabled tools. An example of a such a tool is the Amyuni PDF Creator. Unlike other XMP-enabled tools which can only include standard XMP metadata, the Amyuni PDF Creator enables developers to include their own customized XMP schemas. This ability gives developers and document managers more authoring, tracking, and archiving options.

In part 2 of this article, we shall look at how a product like the Amyuni PDF Analyzer can be automated on a server to embed custom XMP schema extensions into PDF/A documents.

Franc Gagnon is the technical copywriter for Amyuni Technologies