Date   : Sat, 23 Sep 2006 12:24:12 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Compressed ROMFS?

>Message-ID: <4e682b117dinfo@...>
 
Sprow <info@...> wrote:
> As a postscript to my own message, I tried some bitmapped data too (very
> high proportion of 0's for black) and that compressed by 61%.
 
*ScrSave and *ScrLoad use RLE and give good compression.
 
> Lastly I wrote an RLE compressor using the madness proposed in
> <4e5b03df85info@...> and that gave
>   For 6502 binaries you can save just 1%
>   For tokenised BASIC you save -2% (ie.bigger!)
>   For bitmap images with high black content 41%
 
The Common Character Compression used in the INFORM ROM gives good
text compression. I have got 25% or more compression. Compressing
common words ("the", "and" and a couple of others) can get to 33%.
See http://mdfs.net/Software/CommandSrc/Compress/Text
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for the Sinclair Spectrum - http://mdfs.net/Software/Spectrum