Path: utzoo!attcan!uunet!sco!brianm
From: brianm@sco.COM (Brian Moffet)
Newsgroups: comp.graphics
Subject: Mapping Color to Black and White
Keywords: CIE has an x-y table, how to convert
Message-ID: <2148@viscous.sco.COM>
Date: 29 Mar 89 22:50:56 GMT
Organization: The Santa Cruz Operation, Inc.
Lines: 25

I am trying to take a color image with know RGB values
and translate it to a black and white image.  I have looked at the
various other methods of denoting color (HSV, etc...)
but these do not seem to take into account the sensitivity of the
eye (which I suppose black and white file is similar to?)

It appears to me, that CIE (method? algorithm? theory?) does take
into account the sensitivity to the eye.  However, I cannot see
how to translate a color to a particular shade of grey.

Could anyone give me some help on this?  Do you take the normalized
vector for a particular color and this is your percentage
in the shade of grey?   (r * 0.??? + g * 0.??? + b * 0.???) = grey.
I get the impression that the various percentages for r, g, and b
should be about .300, .450, and .250 respectively.

I know this has been discussed before, so thanks for bearing with me.

thanks much

brian moffet
-- 
'Evil Geniuses for a Better Tommorrow!'
My opinions do not in any way reflect those of my employer or my fish.
Brian Moffet	brianm@sco.com  {ucscc,uunet,decvax!microsof}!sco!brianm