PostScript (redirected from Post scriptum)

PostScript

The de facto standard page description language (PDL) in the graphics arts industry as well as in commercial printing. Developed by Adobe, many printers and most imagesetters support PostScript by having a built-in PostScript interpreter.

Printing on a PostScript Printer
When a document is printed on a PostScript printer, it is converted to a PostScript file directly from the graphics or page layout program or by the operating system's PostScript printer driver. The PostScript interpreter in the printer converts the text commands into the printer's machine language, which rasterizes the pages and prints them. See rasterize.

When documents are sent to a commercial printer, they are sent in their native page layout format, such as InDesign or QuarkXPress, or as PDF files. The printing house then converts the documents to PostScript.

PostScript and PDF
PostScript was designed as a language to direct the printer or imagesetter hardware. Although based on PostScript, PDF was designed for viewing and interacting with the documents. See PDF and Acrobat.

PostScript Levels
Adobe PostScript Level 2, introduced in 1990, added data compression and enhancements for color printing. Level 3 (1997) added more enhancements and native fonts and the ability to directly support more formats, including HTML, PDF, GIF and JPEG.

Encapsulated Postscript
Encapsulated PostScript (EPS) is a subset of PostScript that is used to exchange graphics in the PostScript format. The graphics content may be any combination of vector and raster graphics as well as text. See EPS, Adobe Type Manager and PostScript fonts.

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(language, text, graphics)

PostScript - A page description language based on work originally done by John Gaffney at Evans and Sutherland in 1976, evolving through "JaM" ("John and Martin", Martin Newell) at XEROX PARC, and finally implemented in its current form by John Warnock et al. after he and Chuck Geschke founded Adobe Systems, Inc. in 1982. PostScript is an interpreted, stack-based language (like FORTH). It was used as a page description language by the Apple LaserWriter, and now many laser printers and on-screen graphics systems. Its primary application is to describe the appearance of text, graphical shapes, and sampled images on printed or displayed pages. A program in PostScript can communicate a document description from a composition system to a printing system in a device-independent way. PostScript is an unusually powerful printer language because it is a full programming language, rather than a series of low-level escape sequences. (In this it parallels Emacs, which exploited a similar insight about editing tasks). It is also noteworthy for implementing on-the fly rasterisation, from Bezier curve descriptions, of high-quality fonts at low (e.g. 300 dpi) resolution (it was formerly believed that hand-tuned bitmap fonts were required for this task). PostScript's combination of technical merits and widespread availability made it the language of choice for graphical output until PDF appeared. The Postscript point, 1/72 inch, is slightly different from other point units. An introduction. ["PostScript Language Reference Manual" ("The Red Book"), Adobe Systems, A-W 1985].