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From: henry@angel.Eng.Sun.COM (Henry McGilton)
Newsgroups: comp.lang.postscript
Subject: Re: Encapsulated PostScript
Summary: Well, almost . . .
Message-ID: <1793@exodus.Eng.Sun.COM>
Date: 29 Oct 90 18:55:16 GMT
References: <1657@merlin.bhpmrl.oz.au> <1661@merlin.bhpmrl.oz.au>
Sender: news@exodus.Eng.Sun.COM
Lines: 36

In article <1661@merlin.bhpmrl.oz.au>, paulg@bhpmrl.oz.au (Paul Gallagher) writes:
    *  re: EPS/Postscript files.
    *  Encapsulated postscript files actually contain the
    *  postscript commands for printing device-resolution
    *  independant images,
True, but, . . .
    *  followed by a lo-res PICT (bit-mapped) image for the
    *  purposes of previewing the final output.
The preview section is optional.  It doesn't have to be there at all.
If it is there, it can be PICT, or TIFF, or, following the latest EPSF
specification, can be an all ASCII preview section.  Adobe Illustrator
is (was) a good example of an application that (used to) emit(s) perfectly
good Encapsulated PostScript without a preview section.
    *  Hence "encapsulated".
`Encapsulated' really means that the file of PostScript code
can be incorporated (as a `capsule') into the middle of another
file of PostScript code, and can be correctly positioned, scaled,
rotated, and so on.
    *  "Normal" postscript files only contain the code.
See the note on Adobe Illustrator above.

There are really very few criteria for what differentiates 
Encapsulated PostScript from `normal' PostScript:

    o   an Encapsulated PostScript file should be only one page.

    o   an Encapsulated PostScript file should contain bounding
	box information so as to enable the including application
	to correctly position and scale it on the final output page.

    o   there are other criteria such as being `well behaved', that
	are documented adequately in the Adobe specifications.

In other words, there's no real `magic' about Encapsulated PostScript.

	........  Henry