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From: orthlieb@adobe.COM (Carl Orthlieb)
Newsgroups: comp.lang.postscript
Subject: Re: A program to convert .ps to .eps?
Message-ID: <5964@adobe.UUCP>
Date: 27 Aug 90 18:10:08 GMT
References: <90232.075141HBX@psuvm.psu.edu> <19969@orstcs.CS.ORST.EDU> <24138@fmsrl7.UUCP>
Reply-To: orthlieb@adobe.UUCP (Carl Orthlieb)
Organization: Adobe Systems Incorporated, Mountain View
Lines: 47

In article <24138@fmsrl7.UUCP> hugh@slee01.srl.ford.com (Hugh Fader) writes:
>I recall reading that a bitmap may optionally be included in the
>eps file. The bitmap is to be used to render the postscript figure
>by programs such as Frame. Does anyone know how to generate this
>bitmap?

The following is an extract from the Document Structuring Conventions 
v3.0 that might help. You can get the EPSF specification from our server
(ps-file-server@adobe.COM).

	%%BeginPreview: <width> <height> <depth> <lines>
		<width> ::= <uint>  /* Width of the preview in pixels */	
		<height> ::= <uint> /* Height of the preview in pixels */
		<depth> ::= <uint>  /* Number of bits of data per pixel */
		<lines> ::= <uint>  /* Number of lines in the preview */
	%%EndPreview (no arguments)

	These comments bracket the preview section of an EPS file in 
	Interchange format (EPSI). The EPSI format is preferred over other
	platform-dependent previews (for example, Apple Macintosh and IBM
	PC) when transferring EPS files between heterogenous platforms.
	The width and height field provide the number of image samples
	(pixels) for the preview. The depth field indicates how many bits
	of data are used to establish one sample pixel of the preview
	(typical values are 1, 2, 4, or 8). The lines field indicates how
	many lines of hexadecimal data are contained in the preview, so
	that an application disinterested in the preview can easily skip
	it.

	The preview consists of a bitmap image of the EPS file, as it 
	would be rendered on the page by the print or PostScript language
	previewer. Applications that use the EPS file can then place the
	diagram in the including document. Each line of hexadecimal data
	should begin with a single percent sign. This makes the entire
	preview sectiona PostScript language comment so that the file
	can be send directly to the printer without modification.

	The EPSI preview should be placed after the %%EndComments in the
	document file, but before the defaults section (%%Begin(End)Defaults),
	if there is one, and before the prolog (%%BeginProlog) definitions.

	Note: Preview comments can be used only in documents that comply
	with the EPS file format. See "Encapsulated PostScript Files
	Specifications v3.0" for more details, including platform-specific
	versions of the preview.

Carl 8-)