colormap ramp not linear?

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Article #163

#163

From: Larry Gelberg
Date: Thu, 05 Nov 1992 21:18

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A recent net inquiry asked about the apparent non-linearity of the
alpha channel in the default colormap.  You are correct, sir!  We 
initially had a linear hue and opacity ramp, but early on discovered
that we wanted more 'sensitivity' in the lower range than was afforded
by the linear ramp so we replaced it with a logrithmic one.  

Unfortunately, there is an outstanding bug in that it is DRAWN as a
linear map.  What should probably be the case is (a) having the option
for linear vs. logrithmic mapping and (b) regardless, displaying it
the correct way.   We're sorry if this is a real annoyance to you - 
hopefully it'll be fixed in AVS5.  But at least your suspicions are 
right on.

larryg

--
=== Larry Gelberg ============================ larryg@avs.com =======
      Advanced Visual Systems Inc. (AVS Inc.)
      300 Fifth Ave, Waltham, MA 02154
===== Tel: 617-890-4300 = Fax: 617-890-8287 =========================

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Path: arc1-ca.pugleaf.net!sparky!uunet!caen!sol.ctr.columbia.edu!aurora!larryg
From: larryg@avs.com (Larry Gelberg)
Subject: colormap ramp not linear?
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Date: Thu, 5 Nov 1992 21:18:49 GMT
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