What are rle_compress() and rle_decompress() supposed do?   Is it true that 
bwt_compress() and bwt_decompress will only work on strings and not binary 
data?

-----Original Message-----
From:	Michael Neumann [SMTP:neumann / s-direktnet.de]
Sent:	Monday, March 19, 2001 11:03 AM
To:	ruby-talk ML
Subject:	[ruby-talk:12876] Re: Looking for a decent compression scheme

Algorithm
Robert Feldt wrote:
> On Mon, 19 Mar 2001, Michael Neumann wrote:
>
> > bzip2 uses BWT (I don't recall what that stands for).
> > You can use BWT in combination with RLE which results in
> > better compression as RLE alone.
> >
> BWT is Burrows-Wheeler transform.
>
> > I've implemented BWT some time ago in Ruby, but the whole program
> > including RLE was about 100 lines of code.
> >
> > If you're interested I'll send you the sourcecode.
> >
> I'd be interested; please send it to me.

The source is below.
BWT only is very short, but it makes no sense to use BWT alone, because it 
do not compress.
> > Another way could be to use what I call "bit table" compression,
> > where I generate an array of the most frequently used characters
> > and compress the whole data with a reduced bit-size (e.g. 5 bit).
> >
> Sounds like Huffman-coding to me?

Only that I do not create a tree.