Xref: utzoo comp.graphics:10282 comp.sys.ibm.pc.programmer:311
Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!microsoft!kensy
From: kensy@microsoft.UUCP (Ken SYKES)
Newsgroups: comp.graphics,comp.sys.ibm.pc.programmer
Subject: Re: 256 GrayScale Matching to 256 Colors
Keywords: Look Up Table Needed
Message-ID: <53002@microsoft.UUCP>
Date: 8 Mar 90 19:12:05 GMT
References: <858@dukempd.phy.duke.edu>
Reply-To: kensy@microsoft.UUCP (Ken SYKES)
Organization: Microsoft Corp., Redmond WA
Lines: 13

Hello,

   PCs are only able to display 64 shades of a given component since the
D/A converters are 6 bits.  To display these images on your screen fill
up the first 64 entries of your palette with <0,0,0>,<1,1,1>,...,<63,63,63>
and then place the data in the frame buffer, multiplying each value by
63/255.  This will linearly scale your grayscale values to the proper range.
There are several books that explain how to program PC displays at B. Dalton
et al.

Hope this helps,

   Ken Sykes