ment. Also, a device-independent screen representation called EPSI is
specified in section section 6.” It is recommended that all applications sup-
port this format.
5.1
Apple Macintosh PICT Resource
A QuickDraw™ representation of the EPS file can be created and stored as
a PICT resource in the resource fork of the EPS file. It must be given resource
number 256. If the PICT exists, the importing application may use it for
screen display. If the
picframe
is transformed to PostScript language
coordinates, it should agree with the
%%BoundingBox:
comment.
Given the size limitations on PICT images, the
picframe
and bounding box
may not always agree. If there is a discrepancy, the
%%BoundingBox:
must
always be taken as the “truth,” because it accurately describes the area the
EPS file will image.
5.2
Windows Metafile or TIFF
Either a Microsoft Windows Metafile or a TIFF (tag image file format)
section can be included as the screen representation of an EPS file.
The EPS file has a binary header added to the beginning that provides a sort
of table of contents to the file. This is necessary because there is not a second
“fork” in the file system as there is in the Macintosh file system.
Note
It is always permissible to have a pure ASCII PostScript language file as an
EPS file in the DOS environment.
The importing application must check the first 4 bytes of the EPS file. If they
match the header as shown in Table 1, the binary header should be expected.
If the first two match
%!
, it should be taken to be an ASCII PostScript
language file.
Table 1
DOS EPS Binary File Header
Bytes
Description
0-3
4-7
8-11
12-15
16-19
20-23
24-27
Must be hex C5D0D3C6 (byte 0=C5).
Byte position in file for start of PostScript language code section.
Byte length of PostScript language section.
Byte position in file for start of Metafile screen representation.
Byte length of Metafile section (PSize).
Byte position of TIFF representation.
Byte length of TIFF section.
5 Device-Specific Screen Preview
23