Color Conversion Functions
Conversion of Munsell notation to “something” that can be displayed
on-screen (sRGB color representation) is probably the most common color
transformation applied to soil morphology data. The
munsell2rgb() function is convenient for this operation
when Munsell notation has been split into vectors of hue, value, and
chroma. These could be columns in a data.frame or separate
vectors. The parseMunsell() function is convenient when a
full Munsell notation is given as a character vector. Note that
parseMunsell() is a wrapper to munsell2rgb().
For example, converting 10YR 4/6 with either function can
return:
- hex-notation of a color:
#805921FF, or - sRGB color coordinates:
0.5002233 0.3489249 0.1287694, or - CIELAB color coordinates:
40.95021 10.31088 37.49513.
Selection of the closest n Munsell color “chips”, given
sRGB or CIELAB colorspace coordinates is performed with the
col2Munsell() function. Input to this function can be
colorspace coordinates, named colors (e.g. red), or
hex-notation of a color. For example, the selection of the closest
Munsell chip for CIELAB coordinates
(51.4337, 9.917916, 38.6889) results in
10YR 5/6 with a reported sigma (error) of
1.5e-6. This error is estimated as the CIE2000
distance between the source CIELAB coordinates and the CIELAB
coordinates of the closest Munsell chip.
A representative Munsell color can be estimated from reflectance
spectra in the range of 380nm to 730nm with the
spec2Munsell() function.
