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