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Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!necntc!ames!xanth!kent
From: kent@xanth.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: Wishlist for A3000
Message-ID: <3423@xanth.UUCP>
Date: Wed, 18-Nov-87 00:47:16 EST
Article-I.D.: xanth.3423
Posted: Wed Nov 18 00:47:16 1987
Date-Received: Sat, 21-Nov-87 06:58:07 EST
References: <74@mothra> <33314@sunnny.side.up> <2213@gryphon.CTS.COM> <1364@squeaker.munsell.UUCP> <1871@cadovax.UUCP>
Reply-To: kent@xanth.UUCP (Kent Paul Dolan)
Organization: Old Dominion University, Norfolk Va.
Lines: 37
Keywords: continuous tones, Mach banding
Summary: How many colors is "enough"


In article <1871@cadovax.UUCP> keithd@cadovax.UUCP (Keith Doyle) writes:
>In article <1364@squeaker.munsell.UUCP> klm@squeaker.UUCP (Kevin [Being Weird Isn't Enough] McBride) writes:
>>Higher res, yes!  16 meg colors?  WHY??!!  Your eye can't see that many!
>>Granted that for doing real image processing you need that precision
>>internally (8 bits each of R,G, and B; or uvL or what have you), but for
>>display purposes you only need between 2K and 4K colors to get excellent
>>results on a HIGH RES monitor (at least 1K x 1K.)  Any more colors than that
>>and you go into overkill mode, which makes your hardware very expensive.
[...]
>
>Uh, I beg to differ.  [...]
>No, 4k is definately NOT ENOUGH.  I don't know just how much *is* enough,
>but it ain't 4096.

I remember a demonstration from an old SIGGRAPH publication of an
effect called Mach banding, in which a continuous color sweep in x,
constant in y, seemed to have vertical bands through the picture.  To
get rid of this effect took between seven and eight bits per color gun
depending on the observer.  This is a measure of the color sensitivity
of the human eye.  You probably can't give names to the 16 million
colors, or say whether two isolated blocks are the same or different,
but if you don't have that much color resolution, your eye can
definitely find artifacts due to the bandwidth limitations.

Moral, 4K is NOT "enough"; however, 4K is reasonable for an affordable
machine; that is for the hardware.  It would be nice, but probably not
cost effective, for Intuition to directly support 24 or 32 bit add-on
frame buffers, for those who want quality no matter what the cost, but
think the Amiga is mostly where quality is these days.

Kent, the man from xanth.

"Of course I'm coming. ...  When you leave, the average level of
intelligence will rise six points.  I wouldn't be able to live in so
lofty an atmosphere."  -- "Things in their Season", _High Crimes and
Misdemeanors_, Joanne Greenberg