estimateSoilColor: Estimate dry soil colors from moist soil colors and vice...

In aqp: Algorithms for Quantitative Pedology

Estimate dry soil colors from moist soil colors and vice versa.

Description

Soil color is typically described at dry and moist conditions. This function attempts to estimate soil color at dry or moist condition when one is missing. Estimation proceeds as:

• convert Munsell notation to CIELAB color coordinates via munsell2rgb()

• apply scaling, rotation, and translation parameters in CIELAB color space

• convert CIELAB to sRGB coordinates

• locate closest Munsell chip to sRGB coordinates via rgb2munsell()

Estimation of dry from moist soil color state is not guaranteed to be symmetric with estimation of moist from dry.

Usage

estimateSoilColor(hue, value, chroma, sourceMoistureState = c("dry", "moist"))

Arguments

hue	vector of Munsell hue ('10YR', '2.5Y', etc.)
value	vector of Munsell value (2,2.5 2.5, 3, 5, 6, etc.)
chroma	vector of Munsell chroma (2, 3, 4, etc.)
sourceMoistureState	character, source colors are either 'dry' or 'moist'

Details

Scaling, rotation, and translation parameters for shifting between dry <–> moist CIELAB coordinates was determined using vegan::procrustes(), from those official series descriptions (OSD) where moist and dry soil colors were available.

Estimates for colors having a (dry or moist) Munsell value of 10 are not likely correct.

This is still a work in progress.

Value

data.frame of estimated colors in Munsell notation. The sigma column contains CIE2000 color contrast metric values describing the perceptual distance between estimated color in CIELAB coordinates and closest Munsell chip.

Author(s)

D.E. Beaudette

Examples

# keep examples from using more than 2 cores
data.table::setDTthreads(Sys.getenv("OMP_THREAD_LIMIT", unset = 2))

estimateSoilColor(hue = '10YR', value = 3, chroma = 3, sourceMoistureState = 'moist')

# note that estimation is not symmetric
estimateSoilColor(hue = '10YR', value = 5, chroma = 3, sourceMoistureState = 'dry')

aqp documentation built on Sept. 8, 2023, 5:45 p.m.