Tutorial on Vectorial Color, 2007 November 6

Jim Worthey • Lighting & Color Research • jim@jimworthey.com • 301-977-3551 • 11 Rye Court, Gaithersburg, MD 20878-1901, USA

Vectorial Color
Tutorial
At Color Imaging Conference 15
Albuquerque, New Mexico
Tuesday, 2007 November 6, 3:50 - 5:50 pm
Taught by Jim Worthey

News flash on the evening of 2007 November 6:
The tutorial occurred with 10 Students. They were great students and they posed for a class picture. Below the picture is important information about the class.

For the full jpeg from the camera, right-click this link and save it.

Course Description: Use of color vectors can demystify camera sensors, lighting, and other topics, but new color matching functions (CMFs) are needed. Orthonormal opponent CMFs map lights into Jozef Cohen’s logical color space and establish intuitive axes: whiteness, red-green, and blue-yellow. Color mixing is summarized by an invariant curve in 3D, the locus of unit monochromats (LUM). If a camera’s LUM matches the eye’s, it meets Luther’s criterion. Worthey presented details at CIC’s 12 and 14. The tutorial will emphasize the practical use of color vectors and the orthonormal CMFs. If you’ll bring a computer, please install a VRML viewer. For background, see www.jimworthey.com .

Benefits: This course will enable the attendee to

use the orthonormal CMFs, and calculate color vectors.
understand the Locus of Unit Monochromats and the role of vector amplitude.
work with 3D plots of such data as color chips under a lighting change.
Generate a camera’s orthonormal basis, and compare it to the eye’s. The algorithm is simple, then understanding may take a little time.
Using the camera’s orthonormal basis, compare light sources; thus analyze a copier or flash camera.

Intended audience: Scientists and engineers who design or apply camera systems or lights. While certain applications will be stressed, the vectorial approach applies to all color work. For example, multi-primary systems and image compression are natural applications.

James Worthey received a BS in EE and an MS in Physics, then a PhD in Physiological Optics from Indiana University. He researched lighting and color at the National Institute of Standards and Technology, and published several applications of opponent colors. A breakthrough came in 2003 when he combined opponent colors with Cohen’s ideas and computer graphics.

Background Information

VRML viewer: If you are considering the tutorial, or just want to browse this web site, it will be helpful to install the Cortona VRML Viewer, so you can view the 3-dimensional graphs:

Click this link: http://www.cortona3d.com/
Click the button that says "Cortona3D viewer."
Then click for "Install Cortona VRML client," etc.
The Cortona (Parallel Graphics) web site apparently detects your browser. So, to install for different browsers, you need to start over, using the target browser to contact the web site.
As far as I know, there are versions for different Windows browsers, and also for Apple.
If you will bring a computer to the tutorial, please install the viewer on it.

Reading materials:

Draft article "Vectorial Color," and the Figures to go with it.
Paper as presented at Color Imaging Conference 12: Color Matching with Amplitude not Left Out . Concise introduction to color vectors.
The visuals for CIC 12, which include animated and 3D graphs.
Paper as presented at Color Imaging Conference 14 in 2006: Camera Design Using Locus of Unit Monochromats .
To study a few of the key ideas, separated from the larger discussion, check out the newly written Questions and Answers.
The tutorial is intended to teach the practical use of vectorial ideas. Therefore, you might want to look at the Computer Programming Examples.
For total practicality, see the tabulation of the orthonormal functions.
During and after the tutorial, you may be especially interested in the set of 5 worked examples .
For some detailed ideas on lighting and color--perhaps after the tutorial--see the graphical materials on How White Light Works, or the short proceedings paper on that topic.
Class notes.
Visuals for the tutorial itself.

¡See you in Albuquerque!

Jim Worthey Home Page: http://www.jimworthey.com