A Page Description Language is a language for describing the graphical appearance of pages. A high-level imaging model enables applications to describe the appearance of pages containing text, graphical shapes, and sampled images in term of abstract graphical elements rather than directly in terms of device pixels. Such a description is economical and device-independent and can be used to produce high-quality output on a broad range of printers and displays.
PDF uses the Adobe imaging model, a simple and unified view of two-dimensional graphics. In this model, "paint" is placed on a page in selected areas. A page's content stream contains operands and operators describing a sequence of graphics objects. The current page is initially blank. As each graphics object in the content stream is encountered, marks are placed on the current page which completely obscure any previous marks they may overlay. When the content stream has been completely consumed, the page is complete.
The description of a Page Description Lang is taken from the PDF 1.3 Reference Manual @@ADD link here@@
$Date: 2001/07/20 17:06:04 $ Katie Haritos-Shea