PDF knowledge
Find articles that provide you with practical insight into the world of PDFs. Learn all the ins and outs of PDFs, from the fundamentals to the best practices.
Tech corner
PDF 2.0 - A quick overview
It is rare for industrial products to survive for more than 20 years – especially in the IT industry. Not even the inventors of the PDF could have imagined just how successful their file format would be when they launche ...
Tech corner
PAdES - PDF Advanced Electronic Signature
What is PAdES? What does it have to do with PDF? What can PAdES do? For all these questions, there are detailed answers on the web. This article is meant to give a brief overview as a small guide in the jungle of terms.
Tech corner
Do the PDF scan conversion rules have an impact on anti-aliasing?
The scan conversion rules in PDF are special in the sense that none of the publically available graphics libraries implements them. On the other side almost every PDF rendering engine implements an anti-aliasing mechanis ...
Tech corner
Utility to simplify the import of certificates and private keys into a PKCS#11 cryptographic token (HSM)
The 3-Heights™ Security API supports the creation and verification of digital signatures using a cryptographic token via a PKCS#11 interface. However, the component can only be used if the token has appropriate certifica ...
Tech corner
How to create tagged PDF/A from Microsoft Word documents with decent quality
Microsoft Word offers an add-in to save a document as a PDF/A file. Good to hear, I thought. I ran the output through the PDF Validator for a standards conformance check. No complaints. That's great, isn't it. So, I shed ...
Tech corner
A best practice for using output intents
Output intents describe the characteristics of the device on which a document is intended to be rendered. Traditionally, the target device is a printer. But, how about display monitors?
Tech corner
How to process device specific colors in PDF
The chapter about rendering in the PDF standard specifies how to transform colors from one device specific color space to another and gives hints on how to transform calibrated colors to device specific colors. But most ...
Tech corner
A good PDF printer tool can be amazingly versatile
As the name suggests a PDF printer tool is meant to put the contents of a PDF document onto paper. However, it is surprising how many applications can be built when using a printer tool in collaboration with the Windows ...
Tech corner
Converting invoice documents to the ZUGFeRD data format
XML or PDF? That's one of the most heard questions when it comes to invoice document formats. XML is the preferred format for machines whereas PDF is the format for humans. But why not have the cake and eat it? With ZUGF ...
Tech corner
Is the PDF version information a neglectable detail?
Each PDF file starts with a header comment that carries version numbers. What do they mean? Can a reader ignore these numbers or what is it to do? Is there any other version information that a reader should take care of?
Tech corner
How to avoid implementation dependent appearances of annotations and interactive form fields
Annotations such as notes and links belong to the most appreciated PDF features. Although they are easy to use from a user's perspective this is certainly not true from a developers perspective since it is often not clea ...
Tech corner
The PDF Forms Babylon - AcroForms and XFA
PDF forms are very popular among users. A tools programmer can, however, choose between two different forms systems: AcroForm and XFA. When to choose which and why?