Mark Stephens

  https://www.idrsolutions.com Mark founded the company and has worked with Java and PDF since 1997. The original creator of the core code, he is also a NetBeans enthusiast who enjoys speaking at conferences and reading. He holds an Athletics Blue and an MA in Mediaeval History from St. Andrews University.

   



196 Stories by Mark Stephens

How does CCITT compress image data?

How does CCITT compression work? CCITT encodes black and white data. It does this by encoding runs of black or white pixels. We can...
3 min read

Java and anti-aliasing

Anti-aliasing is the processes of making the edges of lines on shapes or text less jagged. This is done by fooling the eye –...
1 min read

How to extract JPG data from PDF

Overview It is actually possible to extract some raw images from the PDF file. In general, images do not exist inside a PDF file...
1 min read

Why writing a PDF parser is such a ‘challenging’ task (part 234)

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