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.
Font subsetting - how it works and when to use
In order to reduce the file size PDF producers use a technique called font subsetting. What does exactly happen with the fonts and what are the consequences?
Image detection in scanned images
Detecting pictures in scanned document pages has many advantages such as better compression rates and the possibility to extract them individually.
How to convert signed documents to PDF/A?
I often get the question whether it is possible to convert digitally signed documents to PDF/A. Because there's no short answer to this I thought it would be helpful to explore the topic a bit into more detail. What tec ...
Digging for information by extracting data from a PDF document
Extracting text from a PDF document is one of the most popular information retrieval function. But how about other information such as images, metadata and more? It can be simple - but also tricky.
The caveats of assembling PDF/A documents
Assembling PDF documents from various sources is a crucial part of an output management system. And, as the document needs to be archived in most cases, it should conform to the PDF/A standard. But, is there a way to ass ...
The versatility of a PDF viewer
Almost every user knows: a PDF viewer is not just a display tool for a well known document format. It provides many more functions, runs on many platforms, offers interfaces in many technologies and serves as an importan ...
Importing images into a PDF file - a seemingly trivial task
A picture is worth a thousand words. That's why they are fondly embedded in PDF files. One would expect that embedding images in a PDF file is a simple task. Because it seems so easy, there are also many, including free, ...
Does OCR make sense for digitally generated PDFs?
Scanned PDF files usually consist of one raster image for each page. The OCR engine can recognize the text in this image and make the document searchable. But what about digitally generated documents?
The Advantages of PDF/A-3 in Practice
PDF is a widely used digital document format for secure and easy access to documents. The latest version of the format, PDF/A-3, offers the added benefit of being able to store and archive files of any format, including ...
Electronic Signatures – A Crash Course
What is a reliable way to digitally sign documents? In this article, we'll explain the differences between electronic signatures and digital signatures, explore the types of signatures used in practice, and discuss the b ...
Can linearization be combined with digitial signatures and PDF/A conformance?
Linearization is a feature to optimize PDF files for sequential reading. Although it is very useful in web based applications it interferes with other features such as digital signatures.
Are the PDF/A space requirements a show stopper for archiving?
A PDF/A document requires that all resources such as fonts, color profiles, etc. must be embedded in the file. The archiving of transactional documents can be nightmare because such documents are usually short by nature ...