aqp (version 1.25)

pms.munsell.lut: Pantone Colors / Munsell Lookup Table

Description

A simple lookup table to convert Pantone spot colors into Munsell notation. Association is based on the "closest" Munsell color via CIE2000 distance metric (dE00). This is an experimental association between the two color systems and should not be used for precision color matching or mixing applications.

Possible uses include rough estimation of soil colors in the field, by means of color swatches based on the Pantone system. This type of color matching is most appropriate in an educational setting where official soil color books may be too expensive.

Usage

data(pms.munsell.lut)

Format

code

Pantone spot color code

hex

hex representation of sRGB colorspace, suitable for on-screen use

munsell

Munsell notation of closest color "chip"

dE00

delta-E 2000 metic describing the (perceptual) distance to the closest Munsell chip

Details

For now, lookup is performed by manual subset (see examples 1 and 2 below) or implicit subsetting by way of a join (example 3). Reverse lookup (Munsell -> Pantone) will not always result in a matching color, see example 3 below.

References

Data were sourced from:

• coated colors: https://raw.githubusercontent.com/ajesma/Pantoner/gh-pages/csv/pantone-coated.csv

• uncoated colors: https://github.com/ajesma/Pantoner/raw/gh-pages/csv/pantone-uncoated.csv

Examples

# NOT RUN {
# load LUT
data(pms.munsell.lut)

## 1. Pantone -> Munsell

# colors to match
colors <- c('10YR 3/3', '7.5YR 4/6')

# index / subset match
idx <- pms.munsell.lut$munsell %in% colors
m <- pms.munsell.lut[idx, ]

# simple display
colorContrastPlot(m1 = m$munsell[1], m2 = m$munsell[2], labels = m$code)

## 2. Munsell -> Pantone
colors <- c('723-c', '451-c')

# index / subset match
idx <- pms.munsell.lut$code %in% colors
m <- pms.munsell.lut[idx, ]

# simple display
colorContrastPlot(m1 = m$munsell[1], m2 = m$munsell[2], labels = m$code)
## 3. integration with SPC
data(pms.munsell.lut)
data(sp6)
depths(sp6) <- id ~ top + bottom

# get the closest Munsell chip from color meter data
sp6$munsell <- getClosestMunsellChip(sp6$color, convertColors = FALSE)

# prepare an intermediate data.frame for performing join to LUT
h <- horizons(sp6)[, c(hzidname(sp6), 'munsell')]

# left join
# not all Munsell colors have a paired Pantone color
m <- merge(h, pms.munsell.lut, by = 'munsell', all.x = TRUE, sort = FALSE)

# splice into original SPC
horizons(sp6) <- m

# graphical check
par(mar = c(0, 0, 2, 1))
plotSPC(sp6, color = 'hex')


## 4. multiple Pantone colors matching a single Munsell color
# 
colors <- pms.munsell.lut[pms.munsell.lut$munsell == '5YR 5/5', ]
colors <- colors[order(colors$dE00), ]

par(mar = c(0, 0, 2, 0), fg = 'white', bg = 'black')
soilPalette(colors$hex, lab = colors$code)
title('Pantone Colors Roughly Matching 5YR 5/5', col.main = 'white', line = 0)

# }