Vectorial Color Questions and Answers

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

Vectorial Color
Questions and Answers

Introduction

At this moment (in 2007 June), I have presented vectorial color ideas at four meetings. Audiences have been kind in their comments, but I do get the feeling that vectorial color and the orthonormal basis are seen as a kind of poetry. People think it's all beautiful but does not apply to daily work. I feel the opposite, the ideas are easy to work with and give helpful answers to problems that sorely need them, such as color rendering by lights.

Maybe there are too many interlocking ideas! A question-and-answer format will let us look at some interesting ideas one at a time. JAW

Q and A

Why is projection Matrix R important? Answer
How did Jozef Cohen derive the formula R = A(A'A)⁻¹A' ? Answer
Is projection Matrix R related to the Moore-Penrose pseudo-inverse? Answer
What is the proof that projection Matrix R is invariant? Answer
Can we have fun with orthonormal functions? Answer
If one set of CMFs is "equivalent for matching" to the orthonormal set, how would you get the transform matrix? Answer

Details about Vectorial Color Tutorial to be given at Color Imaging Conference 16 in 2008 November.