It seems he's deleted most of the critical comments.
My comment that I probably should have just passed on:
and his response:
I'm still not sure where those numbers — 1.3M and 900K — come from. Considering an 8bit image has 1.7M possible values, it suggests that I should be able to find 300K AdobeRGB triplets that are somehow not in AdobeRGB and 700K sRGB values (almost half of the available values) that aren't sRGB colors. It makes zero sense. I asked if he would provide just one of the 300K adobeRGB triplets, but he didn't.
Those values represent the gamut volume in cubic DeltaE values. 1 DeltaE is a just perceptible difference in color, which has 3 dimensions, hence the cubic value.
Norman Koren briefly describes how it is calculated and points out that it can be visualized by the 3D gamut plots provided by Colorthink or his own Gamutvision program. Bruce Lindbloom lists the gamut volume for various color spaces as follows: L*a*b, 2,381,085; Adobe RGB, 1,208,631, sRGB, 832,658; and ProPhotoRGB 2,879,058. The L*a*b efficiencies (the percent of the entire Lab Gamut [i.e. all colors visible to the eye] that the working space encompasses) are 97.0%, 100%, 100% and 91.2% respectively. This article from RIT (the
link is to a PDF) describes the calculations in more detail.
The L*a*b gamut efficiency is less than 100% with integer encoding. Some of the values in ProPhotoRGB are outside the gamut of human vision and do not represent real colors, which are visible by definition.
Bill