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Subject:Re[2]: Graphics for both PC and Mac From:"Walker, Arlen P" <Arlen -dot- P -dot- Walker -at- JCI -dot- COM> Date:Fri, 27 Mar 1998 09:03:21 -0600
For vector graphics use EPS, for bitmaps use TIFF.
In general, do not use any platform specific formats, such as PICT or
WMF.
Admirable advice. The problem is both of those formats (EPS and TIFF) *are*
platform-specific, though in a very subtle way.
EPS files are saved with a "preview" image which is used by most
applications to show you what the image looks like. The package doesn't
parse the EPS, but rather positions the preview image on the screen. EPS/PC
uses TIFF for the preview image, EPS/Mac uses PICT, so if you use an EPS
graphic in one of the many applications which relies on the preview image,
then you'll only see the image if you're on the same platform that created
it. Anywhere else, you'll just get a box with an X in it.
TIFF images are dependent upon the byte-order of the system. JARGON ALERT:
The two methods are known as "Big Endian" and "Little Endian," taking their
name from whether the most significant byte of a multi-byte value is first
or last. That's why Photoshop gives you the Mac/PC choice when you specify
TIFF. Many other packages only know how to read TIFF files of the same
byte- order as they are.
I've found GIF and JPEG to be the most hardy of the cross-platform formats.
As someone noted, you can set JPEG to be lossless compression. You will
still get compression, but not the 100:1 compression you often get from
JPEG. If it's an image you going to be returning to again and again to
modify or retouch, I'd definitely recommend a lossless compression. OTOH,
if
you're not going to make continual changes but rather start from the same
base image for any adaptations the lossless compression method isn't as
necessary.
Have fun,
Arlen
Chief Managing Director In Charge, Department of Redundancy Department
DNRC 224
Arlen -dot- P -dot- Walker -at- JCI -dot- Com
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In God we trust; all others must provide data.
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Opinions expressed are mine and mine alone.
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