🚀 go-pugleaf

In article <545@pollux.ss.titech.ac.jp> juni@ss.titech.ac.jp (Junibakuti Sanubari) writes:
>In article <6654@qip.UUCP>, john@anasaz.uucp (John Moore) writes:
>
>I am also interesting to hear something about this transform. Please do
>not left me behind and let me know something about this also. 

The following article was posted to comp.compression a couple of days
ago.  Since it involves the Wavelet Transform, I thought you might
be interested.

		-Ed Hall
		edhall@rand.org

=========
Path: randvax!usc!wuarchive!zaphod.mps.ohio-state.edu!think.com!snorkelwacker.mit.edu!news.media.mit.edu!media-lab.media.mit.edu!eero
From: eero@media-lab.media.mit.edu (Eero Simoncelli)
Newsgroups: comp.compression
Subject: Re: JPEG obsolete
Summary: Fast Wavelet compression software
Keywords: wavelet,pyramid,coder,compression,jpeg
Message-ID: <1991Jun14.184807.27995@news.media.mit.edu>
Date: 14 Jun 91 18:48:07 GMT
References: <1991May30.203723.21550@ns.network.com> <1991Jun1.055212.18204@alembic.acs.com>
Sender: eero@media-lab.media.mit.edu
Organization: MIT Media Laboratory
Lines: 111

For those of you interested in Wavelet compression schemes, I have a
very fast (on the decompression end) pyramid wavelet coder.  It works
reasonably well (informal comparisons seemed noticably better than
JPEG), but there is certainly room for improvement.  It is available
via anonymous ftp -- here is the README file:


--------------------------------------------------------------------- 
---		 EPIC (Efficient Pyramid Image Coder)             ---
---	 Designed by Eero P. Simoncelli and Edward H. Adelson     ---
---		    Written by Eero P. Simoncelli                 ---
---  Developed at the Vision Science Group, The Media Laboratory  ---
---	Copyright 1989, Massachusetts Institute of Technology     ---
---			 All rights reserved.                     ---
---------------------------------------------------------------------

Permission to use, copy, or modify this software and its documentation
for educational and research purposes only and without fee is hereby
granted, provided that this copyright notice appear on all copies and
supporting documentation.  For any other uses of this software, in
original or modified form, including but not limited to distribution
in whole or in part, specific prior permission must be obtained from
M.I.T. and the authors.  These programs shall not be used, rewritten,
or adapted as the basis of a commercial software or hardware product
without first obtaining appropriate licenses from M.I.T.  M.I.T. makes
no representations about the suitability of this software for any
purpose.  It is provided "as is" without express or implied warranty.

---------------------------------------------------------------------

EPIC (Efficient Pyramid Image Coder) is an experimental image data
compression utility written in the C programming language.  The
compression algorithms are based on a hierarchical subband
decomposition using asymmetric filters (described in the references
given below) and a combined run-length/Huffman entropy coder.  The
filters have been designed to allow extremely fast decoding on
conventional (ie, non-floating point) hardware, at the expense of
slower encoding.

We are making this code available to interested researchers who wish
to experiment with a subband pyramid coder.  We have attempted to
optimize the speed of pyramid reconstruction, but the code has not
been otherwise optimized, either for speed or compression efficiency.
In particular, the pyramid construction process is unnecessarily slow,
quantization binsizes are chosen to be the same for each subband, and
we have used a very simple scalar entropy coding scheme to compress
the quantized subbands.  Although this coding technique provides good
coding performance, a more sophisticated coding scheme (such as vector
quantization) using the same pyramid decomposition could result in
substantial coding gains.  EPIC is currently limited to 8-bit
monochrome square images, and does not explicitly provide a
progressive transmission capability.

Epic is available via anonymous ftp from whitechapel.media.mit.edu (IP
number 18.85.0.125) in the file pub/epic.tar.Z.  Comments,
suggestions, or questions should be sent to:

  Eero P. Simoncelli
  Vision Science Group
  MIT Media Laboratory, E15-385
  Cambridge, MA  02139

  Phone:  (617) 253-3891,    E-mail: eero@media-lab.media.mit.edu

References:

Edward H. Adelson, Eero P. Simoncelli and Rajesh Hingorani.  Orthogonal
   pyramid transforms for image coding.  In Proceedings of SPIE,
   October 1987, Volume 845.

Eero P. Simoncelli.  Orthogonal Sub-band Image Transforms.  Master's Thesis,
   EECS Department, Massachusetts Institute of Technology. May, 1988.

Edward H. Adelson, Eero P. Simoncelli.  Subband Image Coding with
   Three-tap Pyramids.  Picture Coding Symposium, 1990.  Cambridge, MA.

USAGE:
------

Typing "epic" gives a description of the usage of the command:

 epic infile [-o outfile] [-x xdim] [-y ydim] [-l levels] [-b binsize]

An example call might look like this:
 
 epic /images/lenna/data -o test.E -x 512 -y 512 -l 5 -b 33.45

Note that:

	1) the infile argument must be a file containing raw image data
	2) this file must be an 8 bit file (not 32 bit or float)
	3) if the size of the image is different than 256x256, you
	   must specify it on the command line.  Currently, the code is
	   limited to square images only.
	4) the binsize can be any floating point number.  Larger
	   numbers give higher compression rates, smaller numbers
	   give better image quality.  Using a binsize of zero should
	   give perfect reconstruction.
	5) Color images can be compressed best by converting from rgb
	   to yiq and compressing each of the components separately.

The decompression command "unepic" is much easier to use.  Typing
"unepic test.E" will create a raw 8bit data file called "test.E.U".
If you don't like that name, you can specify a different name as an
optional second argument.

-- 
Eero Simoncelli
Vision Science Group
MIT Media Laboratory, E15-385
Cambridge, MA  02139