When it comes to printing then all colors in a PDF document are transformed to the native color space of the printing device. If, e.g. a text uses a black RGB color then it is transformed to an equivalent CMYK value which contains contributions from all four color channels. In particular in mass printing applications these "rich black" values are not wanted, however, and it is required to use "true black" colors which use the K channel only. This article gives some ideas how this transform can be achieved.
PDF is more and more finding its way into mass printing applications. However, PDF spool files often ask too much from a print engine resulting in aborts or, even worse, incomplete prints which may not be noticed. What is special about PDF mass printing and what can be done about it?
JBIG2 is a compression algorithm for bitonal images and has been developed to replace the widely used CCITT G4 algorithm because it can reach better compression ratios. However, the algorithm has received a bad reputation which has led some security experts to the recommendation not to use the algorithm anymore. Is this a wise advice or just an overreaction? Why could it go so far?
Detecting pictures in scanned document pages has many advantages such as better compression rates and the possibility to extract them individually.
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?
Digital signatures are still not very widely used and the the knowledge about them is often fuzzy. This article tries to give an overview about this huge and complex topic.