[comp.graphics] New color space

shirriff@sprite.berkeley.edu (Ken Shirriff) (06/08/91)

I've come up with an idea for defining a color space, based on the 3 axes:
red-neutral-green,
blue-neutral-yellow, and
white-neutral-black.

These axes have the advantage that all 11 basic colors (red, orange, yellow,
green, blue, purple, brown, pink, black, white, gray) are grid points on
these axes.
(For instance, orange = (red,yellow,neutral), brown = (red,neutral,black),
pink = (red,neutral,white), gray = (neutral,neutral,neutral))

Has anyone defined a color space based on these axes before or have
I reinvented the wheel?  (I checked Foley & Van Dam, but it only described
RGB, YIQ, HSV, HLS.)

I've worked out a 1-1 mapping between RGB space and the new space. 
I have a X11 demo program available by anonymous FTP from
sprite.Berkeley.EDU in pub/rbwdemo.Z if anyone wants to try this new color
space.

I hope this color space might be more intuitive than others, since it
is loosely based on basic perceptual colors.  Anyways, send me your
comments if it seems interesting.

Ken Shirriff				shirriff@sprite.Berkeley.EDU

mds3399@isc.rit.edu (M.D. Stokes ) (06/10/91)

In article <1991Jun8.002320.21449@agate.berkeley.edu>, shirriff@sprite.berkeley.edu (Ken Shirriff) writes:
> I've come up with an idea for defining a color space, based on the 3 axes:
> red-neutral-green,
> blue-neutral-yellow, and
> white-neutral-black.
> 
> I reinvented the wheel?  (I checked Foley & Van Dam, but it only described
> RGB, YIQ, HSV, HLS.)
> 
yes, ANLAB was one of the first analytical perceptually uniform spaces 
to use such axes back in the early 1940's.  Other common empirical
spaces include Munsell and the Optical Society of America's color
space.  More to the point, the CIE (the international body for color 
standards) standardized CIELUV and CIELAB in 1976.  CIELAB specifically 
has the axes you discussed.  The gory reference if "Color Science" by 
Wyszecki and Stiles (Wiley, 1981).  A more palatable reference for all 
of this color stuff is "Color in Business, Science and Industry" by 
Judd and Wyszecki (Wiley, 1975) or as a quick computer graphics article 
the September 1988 issue of IEEE Computer Graphics.


Hope this helps, if not, I'll be happy to respond to any color science
questions by email.

Mike Stokes mds@judd.rit.edu
Munsell Color Science Laboratory, Center of Imaging Science
Rochester Institute of Technology
Rochester, NY 14623  (716)-475-7186

jangr@microsoft.UUCP (Jan GRAY) (06/14/91)

In article <1991Jun8.002320.21449@agate.berkeley.edu> shirriff@sprite.berkeley.edu (Ken Shirriff) writes:
>I've come up with an idea for defining a color space, based on the 3 axes:
>red-neutral-green,
>blue-neutral-yellow, and
>white-neutral-black.
...
>Has anyone defined a color space based on these axes before or have
>I reinvented the wheel?  (I checked Foley & Van Dam, but it only described
>RGB, YIQ, HSV, HLS.)

Yes.  See Ware, C. and Cowan, W., "The RGYB Color Geometry", ACM TOG 9.2,
April 1990, pp. 226-232.

Jan Gray  jangr@microsoft.com  Microsoft Corp., Redmond, WA  206-882-8080