Regardless of the coordinate system in which an application operates, there
is a convenient way to estimate the bounding box: Print the page, then use a
point ruler to measure from the lower-left corner of the paper to the lower-left
corner of the image. Then measure to the upper-right corner, also using the
lower-left corner of the paper as the origin. These two measurements give the
bounding box and do not depend on any computation.
2.2
Conditionally Required Comments
There are several optional DSC comments that may be conditionally required
for a conforming EPS file. These comments must appear in an EPS file if
certain features are present—for example, comments to bracket the preview
section or to state that a certain language version or language extensions
must be present in the interpreter.
The
%%Begin(End)Preview
comments must bracket the preview section of
an EPS file if the preview is represented in the encapsulated PostScript inter-
change (EPSI) format. See section section 6
,”
for details and an example of
EPSI.
The
%%Extensions:
comment is required if the EPS file requires a PostScript
language interpreter that supports particular PostScript language extensions
to print properly. For example, the EPS file may contain CMYK language
extension operators and must be sent to a printer that can handle those
operators. In such a case, the EPS file must contain either the
%%Extensions: CMYK
or the
%%LanguageLevel: 2
comment.
The
%%LanguageLevel:
comment is required if the EPS file uses Level 2 fea-
tures without providing conditional emulation. With this information, the
including application can alert the user and avoid any errors that would be
generated if the file were sent to a Level 1 printer.
If the EPS file uses language extensions or Level 2 features, and it
provides complete emulation of the features in terms of Level 1 operators,
the
%%Extensions:
and
%%LanguageLevel:
comments are not necessary.
See Appendix D of the
PostScript Language Reference Manual, Second
Edition
for compatibility and emulation strategies.
If the EPS file requires any fonts, files, forms, patterns, procsets (procedure
sets), or any other resources, the appropriate DSC comment must appear
in the header comments section of the file. See the
PostScript Document
Structuring Conventions Specifications
available from the Adobe Systems
Developers’ Association
.
2 Guidelines for Creating EPS Files
9