Path: utzoo!utgpu!watmath!att!cbnewsd!jmdavis
From: jmdavis@cbnewsd.ATT.COM (j.michael.davis)
Newsgroups: comp.sys.amiga.tech
Subject: The Future of HAM
Message-ID: <1075@cbnewsd.ATT.COM>
Date: 9 Aug 89 13:32:54 GMT
Organization: AT&T Bell Laboratories
Lines: 70



Just got finished reading Chuck's note about why 24bit graphics
are economically unfeasable on the Amiga. Good note.

There are some additional points I want to bring up for discussion,
namely HDTV and the future of HAM.

1) HDTV - Chuck pointed out that most people can't tell the difference
        between 15 bit graphics and 24 bit graphics when declaring "good
        graphics" == "TV quality". While true with our TV, engineering a
        future Amiga to have 15 bit graphics seems to be under engineering
        it wrt HDTV. I know the HDTV specs aren't final, but you can rest
        assured the image quality will be vastly improved, and it may be
        improved enough to tell the difference between 15 and 24 bits.


2) NEW HAM MODES - HAM is not a hack! I really thought it was at first, but
        there are some things that are good about it. While I haven't (yet)
        programmed a HAMmer I imagine that deciding how to represent a color
        (given that you can represent them all) is an easier problem than
        deciding which colors to keep and which to throw away as in other
        systems where the table is 256 out of a possible 256K or so. But
        the biggest advantage I see HAM having is that the machine can
        DIRECTLY DISPLAY A COMPRESSED IMAGE!!!!

        Granted, in the HAM image compression information is lost, but these
        images are 1/2 the size of the full 4096 color images, they load twice
        as quickly, you can store twice as many of them, they animate quicker,
        etc. All this because we have a chip that allows us to directly view
        the compressed image.

The new idea for amiga graphics (following Chuck's wish to see articles where
someone suggests something evolutionary and economically feasible) is to
really goose up the HAM modes, possibly put a DSP in there. For example,
why not ALSO include Jay Miner's original HSV HAM? (Where instead of changing
the R or G or B values you change the H or S or V values.) This can be done
without changing the non HAM modes. Of courese, this mode won't work in nonHSV
HAM Amigas, but wait, there is more. At 8 bits per pixel, a HAM mode will be
able to DISPLAY 256K COLORS AT ONCE, with a base register table of 64 colors.
(I know there are 256K pixels on a 512x512 screen, but you get the idea.)


ALSO,

If a DSP is fast enough (and I suspect it is), why not allow direct display
of a Run Length Encoded picture? This one, at least could be made to work
(partially) with existing Amigas that don't have this chip. All that's needed
is a new function that checks for the presence of this chip, and displays
the picture using the chip if it is there, and goes through the normal
uncompression if it isn't there.

These are just two ideas for directly displaying compressed images. THere
are many more image compression schemes out there and the advantages of
directly displaying compressed images are tremendous. Oh, yea, I almost forgot.
Yes, HAM is hard to program, so, if a DSP is going on the machine, why not     
build it to help in the HAMming process?

SUMMARY:
If evolved properly, HAM in many forms, is here to stay. Image production may
need to be done in more "conventional" means but with the use of new chips to
help generate the compressed images as well as displaying them, the Amiga can
continue to realize the many benefits of this mode while other machines suffer
from performance problems when displaying their top end graphics modes.

-- 
----------------------------------------------------------------------------
        I am just about fed up  |       Mike Davis
        and I will only take it |       ..!att!ihlpm!jmdavis
        a few more times.       |