Portable Document Format (PDF) is a file format used to present documents in a manner independent of application software, hardware, and operating systems.

PDF

Why writing a PDF parser is such a ‘challenging’…

In theory the PDF file format is specified in detail and is very precise. In practice, you meet alsorts of ‘interesting problems’ – the...
Mark Stephens
1 min read

How are PDF files protected?

Access to PDF files can be secured so that not just anyone can open them. This is achieved by encryption – the bytes in...
Mark Stephens
1 min read

What are PDF Image Masks?

The PDF Mask features offer a whole set of functionality to allow complicated image drawing to happen. Rather than just sticking an image on...
Mark Stephens
1 min read

How much memory does your Java application use

I wanted to investigate the memory usage of our Java application to see how much memory was being used for a task – in...
Mark Stephens
1 min read

How are text links defined in a PDF file?

When you are viewing a PDF file, you may well notice that (like a web page) there are blue clickable links. These are defined...
Mark Stephens
1 min read

What are PDF Xref tables?

TL;DR: A PDF Xref table is an internal “map” of byte offsets that tells a reader exactly where to find specific objects (like fonts...
Mark Stephens
2 min read