Please note: these demos require a JAVA enabled browser. If
JAVA is not enabled you can view the
x y
chromaticity diagram or the
u' v'
chromaticity diagram. These are gif files, and each one is
about 20 kbytes..
Chromaticity diagrams and conversion
These java applets allow you to select an approximate colour, using
your mouse, and read off its x y and its u'v' coordinates, or, more
accurately, to key in either x and y, or
u' and v', and
read off the conversion into the other system.
Select which diagram you wish to navigate in: x y
diagram or
u'v'
diagram
CIELAB and CIELUV colour spaces
This applet CIELAB and CIELUV
colour spaces allows you to enter the x, y
(or u', v') coordinates of a colour,
together with its relative luminance Y,
and read off the coordinates
in both CIE (1976) L* a* b* and also CIE (1976) L* u* v*. This requires
an
assumption as to the white point. The default is Illuminant 'C',
but you can select 'A' or 'D65' as alternatives, or edit the white
point
coordinates yourself. Hue angle, Chroma and (for CIELUV) saturation are
also calculated. If you then enter the coordinates for a second colour,
the colour differences in CIELAB and CIELUV units are also supplied.
Initially, the first colour is also set to Illuminant 'C' at Y=50,
since a
common need is to find the colour difference from a neutral.
The above applet only works in one direction: to go from L*a*b* to x, y
use this one.These applets are the first fruits of an attempt to
learn java, and are
supplied with no guarantee as to their accuracy.
For more on the CIE system, visit the official
CIE site.
Email: The Colour Group of Great Britain - Homepage
Last Updated 13 November 2005
http://www.colour.org.uk/colcon.html
