Color: from spectrum to tristimulus

Introduction

Edit 30 Oct 2009:
This is the first post about an example on p. 160 of Wyszecki & Stiles (see the bibliography).

and find another edit about the components wrt the dual basis.
End edit.

As always, if my chatter is confusing, just start following the examples.

In a sense, what I am about to do now is one of the most important color calculations I will show you.

How do we get from a spectrum to tristimulus values?

Color: the 1931 CIE color-matching functions and chromaticity chart

Introduction

The CIE chromaticy chart is one of the things we are headed for. Here is a black-and-white drawing of its boundary. I’ll show you later how I got it.

Color: re-doing Cohen’s example

Cohen’s example again

Let me now show you how I would do Cohen’s example. (His computations, pretty much, were the previous post.) I cannot over-emphasize that he deserves a lot of credit for getting the mathematics right, even if he didn’t name it correctly or do it beautifully.

I start with the A matrix: