Path: utzoo!utgpu!watserv1!watmath!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!ugle.unit.no!mack.uit.no!forit.forut.no!torbjorn
From: torbjorn@forit.forut.no (Torbjorn Sund)
Newsgroups: comp.sources.wanted
Subject: Re: Video image compression algorithims
Keywords: video, imaging
Message-ID: <1991Feb8.084146.28893@mack.uit.no>
Date: 8 Feb 91 08:41:46 GMT
References: <181@oneb.UUCP>
Sender: news@mack.uit.no (USENET News System)
Reply-To: torbjorn@forit.forut.no (Torbjorn Sund)
Organization: Norwegian Telecom,Research Dep.,Telemedicine,Tromsoe,Norway
Lines: 12

Algorithm: Since you want compression > 5 your only chance is to use an
irreversible algorithm. The most widely used are variations upon cosine
transform, truncating the coefficients and / or skipping high-frequency
terms. It even has a standard coming from JPEG. With video pictures the
reversible algorithms will only give you compression of 2 (more on
cartoon-like pictures).

Speed: If you want the job done in seconds on a pc-platform you will
have to do it in hardware. There is a chip out there which implements
the JPEG standard, there are also boards with the chip on it. Try
looking through a number of previous Byte`s, new products section, or
maybe someone else can supply a pointer.