This package covers the basic CIE 1931 space, and derived spaces CIE xyY, Lab, and Luv. The equations are taken from Bruce Lindbloom's CIE Color Calculator. Color areas that are *not* covered are:
spectral color data
device color spaces, e.g. RGB and CMYK
color order systems, e.g. Munsell, DIN, NCS, Ostwald, ...
The API is small. There are functions to
convert between CIE XYZ and other CIE spaces
create and perform some standard chromatic adaptation transforms (CATs)
compute 3 standard color difference \(\Delta\)E metrics
retrieve XYZ and xy of some standard illuminants
Package colorscience is a superset of this one.
Packages colorspace and farver have similar functionality,
and are faster because they are in compiled C/C++.
Package grDevices also has similar functionality
(in the function convertColor()),
but is missing chromaticities xy, uv, and u'v'.
Logging is performed using the package logger.
This is a powerful package that allows a separate configuration
for logging from within spacesXYZ, and that is what I have done.
When spacesXYZ is loaded, the logging threshold is changed from INFO to WARN.
To change it back again, one can execute:
logger::log_threshold( logger::INFO, namespace="spacesXYZ" ) # preferred
or
library( logger )
log_threshold( INFO, namespace="spacesXYZ" ) # not preferred
The layout callback function is customized;
it adds the name of the calling function to the message.
To change it back again, one can execute:
log_layout( layout_simple, namespace="spacesXYZ" )
or to install ones own layout function, one can execute:
log_layout( <your function>, namespace="spacesXYZ" ).
The appender callback functions is also customized;
it comes to an immediate stop if the log event level is FATAL or ERROR.
To continue execution after such a log event, one can execute:
log_appender( appender_console, namespace="spacesXYZ" )
The formatter callback function is initialized to be formatter_sprintf();
this should not be changed.
Glenn Davis <gdavis@gluonics.com>
Lindbloom, Bruce. CIE Color Calculator. http://brucelindbloom.com/index.html?ColorCalculator.html
Lindbloom, Bruce. Color Difference Calculator. http://brucelindbloom.com/index.html?ColorDifferenceCalc.html