[A83] Re: ZPic83 compression

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: ZPic83 compression
From: =?iso-8859-1?Q?Jens_Bj=F6rnhager?= <jensbj@home.se>
Date: Mon, 10 Jun 2002 13:21:24 -0700
References: <20020610075430.4659E18007@mx-1.sollentuna.net>
Reply-To: assembly-83@lists.ticalc.org


> I guess it's a lot better than RLE on most pictures. RLE is just a system
> that marks repeated bytes, so:
>
> $12,$12,$12,$12,$12
>
> will be stored as [special byte],$05,$12. Since these repetitions are not
> very rare in monchrome pictures you can use it to compress it. But you can
> see that there are lots of possibilities that wouldn't compress at all.

I use a pixel-per-pixel RLE encoding for my pics, with this method you get
very little or no overhead at all if you have many places with over eight
pixels
of the same kind in succession.

0b,0b,0b,0b,0b would become

$5

/Jens

References:

[A83] Re: ZPic83 compression

From: "Henk Poley" <hpoley@dds.nl>