PDF Reference Version 1.4 is updated, comprehensive reference for software developers to incorporate PDF capabilities into their applications. This can be PDF producer applications (those who "save to" PDF directly) or a PDF consumer applications (those who read the PDF and allows users to modify its contents). New features include filters for JBIG2-encoded data decoding, enhanced encryption and interactive forms, the ability to import content from one PDF to another, additional viewer preferences and trigger events, and support for accessibility for disabled users. This book contains a general description and comparison with architecture PDF PostScript language, and explanation as follows: the syntax of PDF files, objects, and the level of the document; graphics operator, facility to display text in the form of characters or "glyphs" are defined by the font, how description device-independent create pages to fit the output device; version 1.4 'transparent imaging model (which allows objects to be painted with varying degrees of opacity); interactive features, and how PDF can combine a higher level of information that is useful for the exchange of documents between applications. He told of how PDF work (up to the syntax, operators, and PostScript), not how to work with PDF.