Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!ames!ucbcad!ucbvax!sdcsvax!hp-sdd!andrea From: andrea@hp-sdd.HP.COM (Andrea K. Frankel) Newsgroups: comp.graphics Subject: Re: Graphic file formats Message-ID: <656@hp-sdd.HP.COM> Date: Wed, 24-Dec-86 16:16:57 EST Article-I.D.: hp-sdd.656 Posted: Wed Dec 24 16:16:57 1986 Date-Received: Thu, 25-Dec-86 00:38:44 EST References: <6901@decwrl.DEC.COM> <507@elrond.UUCP> <2824@gitpyr.gatech.EDU> Reply-To: andrea@hp-sdd.UUCP (Andrea K. Frankel) Organization: Hewlett-Packard, San Diego Division Lines: 46 Summary: check out the CGM! In article <2824@gitpyr.gatech.EDU> robert@gitpyr.UUCP (Robert Viduya) writes: >GKS Metafile format that ANSI and ISO are supposedly working on. >I've not been able to find this particular standard in the GaTech >library (I'm not sure it's even an accepted standard yet) I think you are referring to the Computer Graphics Metafile (CGM). This IS in fact an accepted standard! As of 8/27/86, it is American National Standard X3.122-1986, available from ANSI 1430 Broadway New York, NY 10018 The same document is also an international standard, IS 8632 (accepted just this fall, and still being typeset I believe). Both standards have four parts: Part 1 defines the functionality, Part 2 is a Character Encoding (cryptic and compact, good for I/O transmission), Part 3 is a Binary Encoding (good for file storage), and Part 4 is a Clear Text Encoding (good if you have to read or edit the thing). The CGM was developed to be used by GKS and others for archiving pictures. In addition to vector graphics functions, it also includes a rudimentary raster format (CELL ARRAY), and "hooks" for putting in implementation-dependent information in the file (APPLICATION DATA, GENERALIZED DRAWING PRIMITIVE, and ESCAPE). The CGM is the basis for the CGI (interface to graphics "Virtual Devices") and for an Extended CGM which will provide GKS audit trail capability and the CGI's extended raster functionality (among other things). By all means, if you want to implement something that has some chance of being portable between different vendors, and an expected lifetime longer than the current rev of, check out the CGM! Andrea Frankel, Hewlett-Packard (San Diego Division) (619) 592-4664 "...like a song that's born to soar the sky..." ______________________________________________________________________________ UUCP : {hplabs|hp-pcd|hpfcla|hpda|noscvax|gould9|sdcsvax}!hp-sdd!andrea UUCP : {cbosgd|allegra|decvax|gatech|sun|tektronix}!hplabs!hp-sdd!andrea ARPA : hp-sdd!andrea@nosc.arpa CSNET : hp-sdd!andrea@hplabs.csnet USnail: 16399 W. Bernardo Drive, San Diego CA 92127-1899 USA