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From: aozer@next.com (Ali Ozer)
Newsgroups: comp.sys.atari.st
Subject: Re: Pictures on the ST
Message-ID: <196@next.com>
Date: 26 Jun 90 14:33:40 GMT
References: <2701@mrsvr.UUCP> <4b28c24a.20b6d@apollo.HP.COM>
Reply-To: Ali_Ozer@NeXT.com (Ali Ozer)
Organization: NeXT, Inc.
Lines: 20

In article <4b28c24a.20b6d@apollo.HP.COM> Steve Rehrauer writes:
> ...  Spectrum does this, and can switch the palette quickly
>enough to let you choose 48 of the possible 512 colors per each of the 200
>lines in a low-resolution screen.  ...
> ... there are Amiga programs that do similar tricks as Spectrum
>does on the ST, giving you all 4096 colors at once.

Yes, there are. But you can get 4096 colors at once using the Amiga HAM mode
(in 320x400 resolution) without the program doing any tricks or the processor
having to do any extra work. This mode essentially compresses 4096 colors (12
bits) down to 6 bits by encoding a pixel color as either one of 16 absolute
entries (selectable as first 16 entries in the color palette) or as the
previous pixel color plus a replacement of one color component (R, G, B).
Photographs of people and scenery and most ray traced pictures end up looking
great in this mode; some pictures suffer from fringing effects, though.

It's of course true that there are programs that resort to changing the color
palette on the fly to give you modes such as 4096 colors at once in hi-res.

Ali Ozer