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. Email: The Colour Group of Great Britain -
Homepage Last Updated 06
March 2009
http://www.colour.org.uk/colcon.html
