Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!ucsd!ucsbcsl!nessus!ivucsb!dan
From: dan@ivucsb.UUCP (Dan Howell)
Newsgroups: comp.sys.amiga
Subject: Re: grey scale --> HAM picture
Keywords: source, help
Message-ID: <528@ivucsb.UUCP>
Date: 12 Feb 89 03:53:50 GMT
References: <6432@thorin.cs.unc.edu> <6452@thorin.cs.unc.edu>
Reply-To: dan@ivucsb.UUCP (Dan Howell)
Organization: The Audio Club at UCSB, Isla Vista, California
Lines: 10

Another thing you might consider is dithering.  Add a random number between
-8 and +8 to the original 8 bit value, making sure not to overflow or
underflow, and take the 4 MSBs of the result.  This should give a result
which will have an apparent grey-scale resolution much higher than 4 bits,
and will also eliminate the "contouring" effect of short-word-length
quantization.

 
-- Dan Howell  <...!pyramid!nessus!ivucsb!dan>  <dan@ivucsb.UUCP>
-- * Note new address path.  Do not use comdesign, use nessus instead. *