Page 110 - Graphic Design and Print Production Fundamentals

98 Chapter 4. Colour Management in the Graphic Technologies
You can see that it is still the comparison of three values: L, C, and H, where C and H are produced
by applying modifying factors to the original Lab values to compensate for perceptual distortions in
the colour space. Each difference is squared and the root taken of the sum of the squares, just as in the
original Delta E formula.

There is an additional refinement in Delta E(2000) where further adjustments are applied to blue and
neutral colours and compensations for lightness, chroma, and hue. This is a much smaller correction than
the change from Delta E to Delta E(94).

The good news is that you don’t need to understand or remember any of the details of these equations.
Just remember that these are real numbers measuring actual plotted distances between colour samples.
Delta E represents the distance between two points in the Lab colour space. Delta E(94) and Delta
E(2000) are enhancements, providing improved numbers that more closely match our perception of
colour differences.

Media Attributions

• Delta E in Lab Colour Space by Ken Jeffrey