[comp.graphics] SUMMARY: Fractal Compression

K.N.R.Conner@newcastle.ac.uk (Kevin Conner) (12/17/90)

Hiya.

About three weeks ago I asked for some references on Picture Compression
algorithms using fractals.  My thanks go to

	Evan Mills - University of Illinois at Urbana
	Mike Brindley - Oregon State University
	Rob Elliott - University of Illinois at Urbana
	Mark Adler - California Institute of Technology, Pasadena

The references I received are :-

	Barnsley, M.F. "Fractals Everywhere"

	Barnsley, M.F. & Sloan, A.D. "A Better Way to Compress Images"
		January 1988 Byte Magazine pp. 215-223
	
	Dewdney, A.K. "A Tour of the Mandelbrot Set Aboard the Mandelbus"
		February 1989 Scientific American pp. 88-91


The article by Dewdney in Scientific American is an introduction to fractals
and the Mandelbrot set.  It is easy to read and shows some striking examples
of what can be produced by examination of the set.

The article by Barnsley and Sloan in Byte Magazine is an introduction to
a technique that they call Iterated Function Systems.  The explanation
of the technique is easy to follow and they even include a BASIC program
to produce the Sierpinski Triangle.  There are some very impressive
examples of the outcome of the IFS technique especially the picture of
the Bolivian girl.  If anyone has a copy of the IFS transforms for the
girl could they please send me a copy?

Barnsley's book is a deeper treatment of IFS.  I'm still in the middle
of reading it so I wont say much except that it is been good so far!

All these articles have references, some of which I'm chasing up.

Thanks again to all who replied,

	Kev

MERRY XMAS

"I didn't say this!  I wasn't here!"

K.N.R.Conner@uk.ac.newcastle          K.N.R.Conner@newcastle.ac.uk
...!ukc!newcastle.ac.uk!K.N.R.Conner

jk87377@korppi.tut.fi (Kouhia Juhana Krister) (12/18/90)

In article <1990Dec17.102951.6334@newcastle.ac.uk>
K.N.R.Conner@newcastle.ac.uk (Kevin Conner) writes:
>Hiya.
>
>The article by Barnsley and Sloan in Byte Magazine is an introduction to
>a technique that they call Iterated Function Systems.
>
>There are some very impressive examples of the outcome of the IFS
>technique especially the picture of the Bolivian girl.

Maybe I remember wrong, but I have never seen an original pictures of
the compressed pictures.
Have somebody seen them? Would somebody describe the differences
between the original and the compressed pictures?

>MERRY XMAS

Xmas, Xmas!!


Juhana Kouhia
jk87377@tut.fi

JOSHI@MTUS5.BITNET (12/18/90)

Which issue of Byte magazine describes "Iterated Function Systems"?
Does anyone have more references on fractal compression. Please
e-mail to        joshi@cimrt2.me.mtu.edu

Thanks in advance
Merry Christmas

hal@eecs.cs.pdx.edu (Aaron Harsh) (12/18/90)

In article <1990Dec17.171417.12499@funet.fi> jk87377@korppi.tut.fi (Kouhia Juhana Krister) writes:
>In article <1990Dec17.102951.6334@newcastle.ac.uk>
>K.N.R.Conner@newcastle.ac.uk (Kevin Conner) writes:
>>The article by Barnsley and Sloan in Byte Magazine is an introduction to
>>a technique that they call Iterated Function Systems.
>Maybe I remember wrong, but I have never seen an original pictures of
>the compressed pictures.
>Have somebody seen them? Would somebody describe the differences
>between the original and the compressed pictures?

  I saw an original and a compressed image in one of the ACM magazines.  I'm
pretty sure it was Barnsley's system.  The picture was a field of sunflowers
with an airplane flying over.  They took the airplane out of the compressed
image to help the compression.  The end result was pretty hideous.  The
original was a digitized picture; the compressed one looked like it was drawn
in crayon.  The compression ratio was pretty impressive though.

Aaron Harsh
hal@eecs.cs.pdx.edu

sw@mdavcr.UUCP (Scott Wood) (12/18/90)

In article <1990Dec17.171417.12499@funet.fi> jk87377@korppi.tut.fi (Kouhia Juhana Krister) writes:
>
>Maybe I remember wrong, but I have never seen an original pictures of
>the compressed pictures.
>Have somebody seen them? Would somebody describe the differences
>between the original and the compressed pictures?
>

The October 1988 issue of IEEE Spectrum had an original and compresssed
picture of a field of sunflowers. Aside from the fact that the original
had an airplane in it, and the compressed didn't (it was removed) I
found it difficult to match up the original and the compressed image.
It's kind of difficult to describe the compressed image, except that to
me it looked more like a painting than a photograph. The sunflowers had
a sort of abstract quality. The compression ratio was 2000 to 1.

scott
-- 
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Scott Wood  ...!uunet!van-bc!mdavcr!sw   sw%mda.ca@wimsey.bc.ca   sw@mda.ca

ge@wn3.sci.kun.nl (Ge' Weijers) (12/18/90)

Does anyone know a good method to compress scanned pictures that does not
have the complexity of IFS. Packing may be slow, but unpacking must be
quite fast. Pictures are 16 colour/640 x 480 pixels.

On the subject of IFS: in "Computer Graphics, principles and practice"
by Foley et. al. IFS is mentioned in passing, about 4 pages.

Ge' Weijers
--
Ge' Weijers                                    Internet/UUCP: ge@cs.kun.nl
Faculty of Mathematics and Computer Science,   (uunet.uu.net!cs.kun.nl!ge)
University of Nijmegen, Toernooiveld 1         
6525 ED Nijmegen, the Netherlands              tel. +3180652483 (UTC-2)

rick@pangea.Stanford.EDU (Rick Ottolini) (12/18/90)

I heard a talk last week by the inventor of wavelet transform of how fractals
and wavelets share similar mathematics.  Wavelet transforms have been used for
data compression, so now I have a better idea how a fractal compression
transform would work.