From: axman@acadia.Kodak.COM (Mike Axman)
Newsgroups: alt.cd-rom,comp.compression
Subject: Re: Photo CD efficiency & patents
Date: 12 Nov 92 21:42:09 GMT
Followup-To: comp.compression
Distribution: alt
Organization: Eastman Kodak Co., Rochester, NY

In article <01GQZ26J742Q002DM8@INDYVAX.IUPUI.EDU>, PAOLIVER@INDYVAX.BITNET writes:
>   Fractal compression, while fantastically computationally
>intense for *encoding*, is very efficiently decoded. It can
>be made pretty lossless. Perhaps not enough so, however. But
>where applicable, it can give excellent results while
>getting far better than 3x compression. You've patronizingly
>dismissed this as, to paraphrase, gaudy new technology, when
>old will do fine.  Well, this pointless new technology lets
>someone put 10,000+ pictures on one CD-ROM with pretty good
>quality ....

I didn't mean to patronizingly dismiss the utility of fractal compression.
However, 2 or so years ago, when development of the Photo CD compression 
scheme was underway, fractal compression had not yet gained attention as 
a high quality (near lossless) scheme.  Quite honestly there is no one 
at Kodak with much experience in fractal compression.  To say the least, 
it would have been a high-risk endeavor.

>
>   660 megabytes of storage space is a fairly arbitrary
>number. But 100 pictures ... ? A nice even human number
>that has little to do with technology, more to do with
>a deliberate design decision. Hence my comment.

Since the compression is variable rate, the 100 number is probably not 
even a good average number.  If you know anything about marketing, 
then you can understand why "100" is an alluring number.  I don't think 
I've ever gotten "100" images on my disks.  Usually closer to 150 with 
a Ektar 25 and Gold 100 films.  Actually, Photo CD came very close to 
adopting the CD-3 media size, in which case the number of images would 
have been significantly less.

>   I simply don't believe that a concerted effort of the
>results of thousands of man hours of thinking time can yield
>nothing better for lossless encoding of picture data than
>Huffman coding (40 years old). 

Okay, I admit it.  A non-zero portion of those "thousands of man hours" 
was spent playing tetris and reading Netnews.  Huffman encoding is 
just the last step in the Photo CD processing.  Although engineering 
the Huffman codebooks was non-trivial, it was only a small part of the 
whole format development.

>Perhaps this is merely my
>astonishment at work here. Perhaps Kodak really did
>find the best available to Mankind when they settled
>on it. 

Here-in lies the problem.  We're speaking different languages.  You have 
this opinion that the Photo CD encoding was designed to be state of the 
art in image compression.  BZZZZT!  It was designed to be a good compromise 
for the intended application.  We looked at the DCT, Q-coder, Subbands, and 
a few other techniques, and then proceeded to "compromise" with the hardware
and software folks.  We couldn't justify the more "intellectually pleasing"
methods which yield greater compression rates, at the expense of computation
and complexity.  There was no conspiracy to undermine the state-of-the-art 
in compression, but we did realize that quite a few Phd-types might not 
be happy with it's simplicity :-)  Oh well, at least we got the product out.

>   I'll believe what you're saying after I see Kodak
>post a reward of, say, $20,000 (a modest sum for Kodak,
>a lot for most academics personally) to the first person to
>come up with a lossless compression algorithm that performs
>an average of 2X or more better than Kodak's scheme on a
>sampling of real world photographs (as opposed to randomly
>garbled bits of junk from a random number generator.) The cost
>savings in disks required would clearly be immense, far
>greater than $20,000.
>   If the problem is as intractable as you claim, Kodak could
>make this offer with no trepidition, couldn't it? At worst,
>it could get better technology for a small cost. If, that is,
>it really wanted it.

I guess you just won't ever believe me then.
You just don't get it do you?  It wasn't a competition for who's 
algorithm gets the best bitrate.  Who cares?  The compression is an almost 
trivial part of the entire system.  Serious discussion was given to 
NOT COMPRESSING THE DATA AT ALL!  However, although I don't have
a Phd in probability theory, I can say that you might not 
realize the extent of what you're saying.  Lossless compression 
researchers would probably give you a metal if you could achieve
a 2X improvement over Huffman encoding.  Q-coding can't, and 
that's state-of-the-art (tm).

In summary, I must say I don't understand your anamosity.  It's like 
complaining to Ford because they don't use the state-of-the-art in 
their Escort.  I would argue that the Photo CD as a whole, is a 
state-of-the-art _concept_, but that there are very few _parts_ of 
it which qualify standalone.  The digital imaging market has hobbled 
along for years, but has yet to make that "break" into the world of 
the typical consumer.  Photo CD is trying to bridge that gap and make 
image scanning a household activity (okay, houselab for now).  It isn't 
trying to dazzle the world of image compression (despite what the brochures
might say).  

Maybe you think the technology and algorithms are outdated, but how many 
_consumer_ ANYTHINGS utilize state-of-the-art technology.  Name one.
Televisions?  Where is HDTV?
Stereos?      What ever happened to Quad?
Automobiles?  Don't make me laugh.
CD-audio?     With PCM encoding?  HA!

Most state-of-the-art things just don't pop-up in many consumer products.



-- 
Mike Axman  
CD-Imaging Advanced Development
Eastman Kodak Company
axman@kodak.com


DISCLAIMER:
Kodak gives me this Net access for free, but they aren't 
responsible for my postings.
Newsgroups: alt.cd-rom