1 Introduction

1.1 Soil Color Contrast Class

1.2 Delta-E

2 Applications

2.1 Setup

library(aqp)
library(soilDB)
library(farver)
library(cluster)
library(ape)
library(colorspace)
library(latticeExtra)
library(knitr)
library(MASS)
library(vegan)

2.2 Core Functions

Soil Survey Technical Note 2

2.2.1 Color Contrast Metrics

Compute several indices of color contrast from 2 vectors of Munsell colors, m1 and m2. Comparisons fully vectorized, e.g. comparisons performed element-wise \(m1_i ~\leftrightarrow~ m2_i\) \(...\) \(m1_n ~\leftrightarrow~ m2_n\).

  • \(dH\): change in Munsell hue, see Hue Position section below
  • \(dV\): change in Munsell value (absolute value of difference)
  • \(dC\): change in Munsell chroma (absolute value of difference)
  • \(\Delta{E_{00}}\): CIE2000 Delta-E #1, #2
  • \(cc\): soil color contrast class (Soil Survey Technical Note 2)

Results as a data.frame.

# examples
m1 <- c('10YR 6/3', '7.5YR 3/3', '10YR 2/2', '7.5YR 3/4')
m2 <- c('5YR 3/4', '7.5YR 4/4', '2.5YR