Re: CNS colors
Subject: Re: CNS colors
From: David Perrell <email@example.com>
Date: Thu, 08 Feb 1996 09:07:23 -0800
From firstname.lastname@example.org Thu Feb 8 12: 08:21 1996
X-Mailer: Windows Eudora Light Version 1.5.2
At 12:01 PM 2/7/96 +0000, Chris Lilley wrote:
>But you write:
>> and I think CNS is a bad idea.
>which would be fine if you had a technical reason, but you go right
>on to say:
>> Obviously CNS (which I'd never heard of before) is a subset of the HSB
>> (hue-saturation-brightness) color model, widely used and intuitive.
>So you have newver heard of it, have a false idea of what it is, and
>confidently state it is a bad idea...
Actually, "I think" isn't all that confident. My point in mentioning my "credentials" was that if CNS had gained widespread acceptance, I would likely have heard of it. In any case, your message corrected a foolish presumption that CNS was being proposed as the primary method for color spec'ing -- a presumption that changed my hue and prompted me to oversaturate my prose. My thoughts have changed, but I'd still like to address some of your comments.
>Perhaps you should have taken the trouble to find out more about it ;-)
Well, it's a lot easier finding out from you than finding a 14-year-old CG&A. ;-) If the paper were readily available to me I'd certainly read it.
>In particular, it has nothing to do with HLS, HSB and suchlike polar
>representations of RGB (which are, in usability studies, often shown to
>be *not* very intuitive).
As described in Hakon Lie's message, CNS colors are distinguished by hue, saturation and lightness. To me, a conceptual relationship to HSB, HLS, and Munsell is implicit.
>I am sure you are also aware that many of the Pantone spot
>colours are not withing the gamut of most RGB monitors.
>TOYO is not "based on HSB" to the best of my knowledge.
I believe it's an evenly spaced range of hues, with evenly spaced saturations of each.
>Monitors do not use the CMYK colour model.
A technological challenge, to be sure. (Point four guns backwards and suck spectrum from a white screen?)
I was trying to make the point that 627 colors don't adequately address the capabilies of either print or display.
>HSB is a spectacularly bad idea as it is non intuitive. It claims for
>example that yellow (RGB 00FFFF) and blue (RGB 00FFFF) have the same
>"brightness" which is clearly false.
I see your point, but isn't a fully-saturated yellow brighter (lighter) than a fully-saturated blue (RGB 0000FF)? With CNS, would "medium vivid blue" be as bright as "medium vivid yellow"?
>The overall concept of a polar model (as used for example by Munsell,
>OSA, Itten, NCS, CIE LCH and so on is fine. The particular
>implementation in HSB is not.
Then I will champion this model no more forever.
>The broadcast industry uses LUV, not LAB
Is it still YIQ for NTSC?
>Indeed, the reason I suggested CNS is that it may be unambiguously
>related to CIE colour spaces.
Sounds good. I'd still argue it should index a finer-resolution color specification. And still wonder how many of those usenet complainers will be hand-coding color a year or two hence.
Apologies for my inaccuracies. Thanks for your corrections and clarification.
Hearn/Perrell Art Associates
Presentation graphics & animation
Photo retouch & enhancement