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

PDF

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...
Mark Stephens
3 min read

How to extract JPG data from PDF

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

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