Calculate Redness Index after Barron & Torrent (1986) "Use of the Kubelka—Munk Theory to Study the Influence of Iron Oxides on Soil Colour" using Munsell colors converted to LAB. DOI: 10.1111/j.1365-2389.1986.tb00382.x. Accepts vectorized inputs for hue, value and chroma, produces vector output.
barron.torrent.redness.LAB(hue, value, chroma)
A numeric vector of horizon redness index (higher values = redder).
A character vector containing Munsell hues (e.g. "7.5YR")
A numeric vector containing Munsell values
A numeric vector containing Munsell chromas
Andrew G. Brown
Barron, V. and Torrent, J. (1986), Use of the Kubelka-Munk theory to study the influence of iron oxides on soil colour. Journal of Soil Science, 37: 499-510. doi:10.1111/j.1365-2389.1986.tb00382.x