Article View: comp.sys.mac
Article #20666Re: Video memory and the Mac II
From: Joel West
Date: Fri, 23 Oct 1987 16:11
Date: Fri, 23 Oct 1987 16:11
37 lines
1794 bytes
1794 bytes
In article <6537@apple.UUCP>, lsr@apple.UUCP (Larry Rosenstein) writes:
> Color Quickdraw supports the old Quickdraw color model of 8 fixed colors and
> maps those colors into the closest available color..
I don't want to get picky (particularly with Larry), but
Color QuickDraw actually:
* maps the eight using 'clut' resource #0, which stores
colors that approximate the ImageWriter II output
* then chooses the nearest available color from the
display's color table
With the 256-color video board, there's a noticeable difference
between these 8 colors and the fully saturated, pure eight:
white
red
yellow
green
cyan
blue
magenta
black
Of course, the IW II ribbon only supports cyan, magenta, yellow
and black, so the other colors (except white) are produced
by two-color combinations.
We put two orthogonal plots of this 8-color clut in an HSV (Hue,
Saturation, Value) cone in the Colorizer manual, and it turns
out that both the saturation and value for green are way off.
Also, magenta is reddish and cyan is bluish, so the IW II
manual calls these "purple" and "blue".
--
Joel West (c/o UCSD)
Palomar Software, Inc., P.O. Box 2635, Vista, CA 92083
{ucbvax,ihnp4}!sdcsvax!jww jww@sdcsvax.ucsd.edu
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!sdcsvax!jww From: jww@sdcsvax.UCSD.EDU (Joel West) Newsgroups: comp.sys.mac Subject: Re: Video memory and the Mac II Message-ID: <4155@sdcsvax.UCSD.EDU> Date: Fri, 23-Oct-87 11:11:31 EST Article-I.D.: sdcsvax.4155 Posted: Fri Oct 23 11:11:31 1987 Date-Received: Sun, 25-Oct-87 15:07:04 EST References: <11827@decwrl.DEC.COM> <6537@apple.UUCP> Organization: Palomar Software, Inc., Vista, CA Lines: 36