A: An Encapsulated PostScript file is a standard PostScript file which conforms to specific conventions and is well-behaved. Well-behaved meaning that and EPS file returns the including environment to its original state upon completion. EPS files may also include a bitmap screen image at the beginning, enabling applications that don't understand PostScript commands, such as word processors, to include and display the illustration on the screen and subsequently print it.\
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For more information see NextAnswer postscript.404. Also, there is documentation available from Adobe Systems on the subjects of EPS files, and Document Structuring Conventions.\
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Q: How do I convert an ordinary PS file into an EPS file? \
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A: There's usually more to it than just changing the extension from ".ps" to ".eps", although you can give that a try. (Save your document before trying!) [Note: NextAnswer postscript.404 suggests a method of testing.]\
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Several things must be true for a PostScript file to be EPS:\
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(1) The original file must be "conforming" PostScript, as evidenced by the following line at the beginning of the file:\
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%!PS-Adobe-2.0\
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(Merely adding this line to a file that isn't conforming PostScript won't necessarily make it conform magically, of course. It also depends on the rest of the contents.) For EPS, this line should be changed to:\
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%!PS-Adobe-2.0 EPSF-2.0\
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This describes a document that meets version 2.0 document structure guidelines as well as version 2.0 EPSF document structure guidelines.\
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(2) It must have a valid bounding box comment in the header, of the form:\
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%%BoundingBox: llx lly urx ury\
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Note these values do not describe an origin and a pair of extents (NeXT style rect description), but rather lower left x and y and upper right x and y. Here's a typical header of an EPS file (notice that the arguments to the bounding box are floating point numbers):\
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%!PS-Adobe-2.0 EPSF-2.0\
%%Creator:Scan\
%%Title:Scanned_Image.eps\
%%Origin:0 720\
%%BoundingBox: 0 0 322 467\
%%EndComments\
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(3) These operators are restricted from use in EPSF (and from conforming documents in general ):\
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banddevice\
copypage\
erasepage\
exitserver\
framedevice\
grestoreforall\
initclip\
initgraphics\
initmatrix\
note\
nulldevice\
quit\
renderbands\
setdevice\
setmatrix\
setpageparms\
setescreen\
settransfer\
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(4) An EPS document should not contain multiple pages, as the format's intention is a portable representation of a single graphic for use by another program, one that might not understand PostScript.\
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(5) Because of this, the format also defines ways of including a bitmap representation for display by non-PS applications. For apps that don't use this information, or EPS files that don't contain a graphic, these comments:\
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%%Creator:\
%%Title:\
%%CreationDate:\
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can be used to provide identifying information for the file if it is not imaged but represented by its bounding box size on the screen (like WriteNow's Hide Graphics mode). These comments are automatically filled in the Appkit's printing methods.\
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This comment:\
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%%DocumentFonts:\
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makes note of fonts used by the graphic which will be needed at imaging time by the application that wants to image that graphic.\
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This comment:\
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%%DocumentNeededFonts:\
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is similar, but the fonts are not contained in the file in question and will have to be found as resources by the code that is running the interpreter. Both/either of the comments can be very important to EPS files that want to be included in other documents and print correctly, especially in a multi-font environment. \
