von dp am 06.Maerz 97 um 01:22:13:
zu: Perlen aus dem Strom der Nachrichten im direct_L von Daniel am 22.Dezember 96 um 02:00:59:
Following up on the discussion earlier about gamma correcting
images to look (close to) the same on Mac and Windows...
>So, what I *should* do is as follows...
>
> 1. take my great looking screenful of graphics and import it
> into Director 4.04. Change the palette there, from Mac system
> (which is what they were created in using PS4) to the Win
> system colours. Show the stage. Take a screen snapshot...
You don't need to do anything to the existing images *yet*. The point is
just to get a copy of the actual Director for Windows palette to work
with in PhotoShop or Debabelizer. You need this to reassign the
pixels in your bitmaps to a differnt palette. You *could* just use
Director's own Transform Bitmap for this, but PS/Debab do a better job.
> 2. Close Director. Open PS4. Reopen up that graphic. Load the
> just-taken SimpleText snapshot under the Colour Palettes
> area...to force that graphic to take on this "new" palette...
Yes, though I'm not familiar enough with PhotoShop to remember the
exact sequence to get the new palette in and make the old bitmaps
use it.
> 3. Save that graphic. Re-import it back into Director and then
> no matter how it looks on my Mac (I author on that platform)
> realize that it will look fine/good/terrific (pick one?) when
> later saved and moved over to the Win platform.
These three steps take care of *half* of the problem-- converting the
bitmap data to use a specific palette that's appropriate for both
Mac and Windows. To get the gamma correction right, you need to further...
--Make a copy of the built-in Director for Windows palette.
--Put that in a single castLib you use for palettes. This becomes
the castLib you always use on the Mac. Save a copy!
--Make all your bitmaps use that palette.
--In PhotoShop or Debab, make a gamma corrected version
of that palette. The image data itself doesn't matter.
This will make your images look unnaturally pale on the Mac.
--Import the picture you just gamma corrected, and put its palette
in the palettes castLib, replacing the Mac version that was there.
Toss the bitmap that comes in with the new palette.
--Make sure the original bitmaps are pointing at the gamma
corrected palette in the same cast position.
--Save this modified castLib and always use this on Windows.
The important thing is to use a castLib that's referenced with the
same castLib number from each movie, and uses palette members
in the same numbered slots. Then, simply substituting the
platfrom-appropriate palettes castLib file will take care of all
the gamma correction issues for you without having to think
about it again.
Your case is relatively simple because all your images are
using a single palette. But the same approach works if
you have different screens using different custom palettes.
Just keep those first and last ten sacred Windows colors
in all your palettes.
>by following this methodology, I'll end up with one set
>of graphics, but two varying palettes...if I've got it right...
Exactly, that's the point-- gamma correction of a single set
of bitmaps, so as to use as little disk space as possible.
Note that this gamma correction technique has no effect
if you are using thousands or millions bitmap members.
The bitmaps have to be 8-bit or less for this gamma correction
to work. However, this gamma correction *will* work if
the video display mode is thousands or millions (because
Director looks at the palette to translate the 8-bit image
into 16- or 24-bit data to draw to the screen).
- Glenn M. Picher Dirigo Multimedia gpicher@maine.com (207)767-8015
D. Plänitz