grDevices::convertColor XYZ space is it really xyY?

Ken, I followed your suggestion and perhaps I don't understand what to expect from convertColor or maybe I'm not using it correctly.  Consider the following tests:

D65 <- c(0.3127, 0.329, 0.3583) # D65 chromaticity coordinates
X <- D65[1]*D65[3]/D65[2] # conversion per brucelindbloom.com
Y <- D65[3]
Z <- D65[3]*D65[3]/D65[2]
XYZ <- data.frame(X = X, Y = Y, Z = Z) # D65 in tristimulus values (?)
colnames(XYZ) <- c("X", "Y", "Z")

tst1 <- convertColor(XYZ, from = "XYZ", to = "sRGB")
tst2 <- convertColor(D65, from = "XYZ", to = "sRGB")
# none of these are 1,1,1, namely white (they are ~ 0.6, 0.6, 0.6)

So it looks like D65, a white standard, does not come back to something near white in the sRGB space.  What am I doing wrong here, or what do I misunderstand?  Please don't say everything!

Thanks, Bryan

Bryan Hanson <hanson <at> depauw.edu> writes:

grDevices::convertColor has arguments 'from' and 'to' which can 

take on value 'XYZ'.  Can 
someone confirm

that 'XYZ' is the same as the CIE chromaticity coordinates 

are also sometimes refered to 
as 'xyY' in

the literature?  Or are these the CIE tristimulus values?  

It looks to me like the first case is 
true, but I

would appreciate hearing from one of the people in 

know.  Thanks, Bryan

I.'d look at the code or put in some known data to test it, 
but XYZ are tristimulus values and xyY are chromaticity
coordinated and the luminance which is the Y tristimulus
value for the CIE 1931 standard observer.

Ken

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