Introduction to spectra2rgb

The hardware and bandwidth for this mirror is donated by dogado GmbH, the Webhosting and Full Service-Cloud Provider. Check out our Wordpress Tutorial.
If you wish to report a bug, or if you are interested in having us mirror your free-software or open-source project, please feel free to contact us at mirror[@]dogado.de.

Overview

spectra2rgb converts hyperspectral reflectance signatures to sRGB hex codes and CIELAB coordinates. It bundles the CIE 1931 standard observer and D65 illuminant, so no external colour-science package is required.

Quick start

library(spectra2rgb)

wl  <- seq(400, 700, by = 10)
ref <- 0.1 + 0.6 * exp(-((wl - 550) / 60)^2)   # synthetic green peak

hs_to_xyz(wl, ref)
#>          X        Y        Z
#> 1 36.62317 52.90519 19.42392
xyz_to_rgb(hs_to_xyz(wl, ref))
#>     R   G  B     hex
#> 1 159 207 90 #9FCF5A

Data-frame workflow

set.seed(1)
wl  <- seq(400, 700, by = 10)
mat <- matrix(runif(5 * length(wl), 0.1, 0.9), nrow = 5)
colnames(mat) <- as.character(wl)
df  <- as.data.frame(mat)

spectra_to_rgb_lab(df, id_col = paste0("leaf_", 1:5))
#>   Sample_ID   R   G   B     hex        L         a         b
#> 1    leaf_1 208 180 193 #D0B4C1 76.00948 12.239545 -2.876998
#> 2    leaf_2 189 195 167 #BDC3A7 77.66141 -6.993776 13.378715
#> 3    leaf_3 176 177 186 #B0B1BA 72.37501  1.385273 -4.708219
#> 4    leaf_4 233 175 176 #E9AFB0 76.75054 21.293901  7.753842
#> 5    leaf_5 213 199 179 #D5C7B3 80.87628  1.597983 11.767690

Missing values

df2 <- df
df2[2, ] <- NA

# Silent zero-fill (default):
spectra_to_rgb(df2, na_action = "zero")
#>   Sample_ID   R   G   B     hex
#> 1         1 208 180 193 #D0B4C1
#> 2         2   0   0   0 #000000
#> 3         3 176 177 186 #B0B1BA
#> 4         4 233 175 176 #E9AFB0
#> 5         5 213 199 179 #D5C7B3

# Drop with warning:
suppressWarnings(spectra_to_rgb(df2, na_action = "drop"))
#>   Sample_ID   R   G   B     hex
#> 1         1 208 180 193 #D0B4C1
#> 2         3 176 177 186 #B0B1BA
#> 3         4 233 175 176 #E9AFB0
#> 4         5 213 199 179 #D5C7B3

# Preserve NA:
spectra_to_rgb(df2, na_action = "keep")
#>   Sample_ID   R   G   B     hex
#> 1         1 208 180 193 #D0B4C1
#> 2         2  NA  NA  NA    <NA>
#> 3         3 176 177 186 #B0B1BA
#> 4         4 233 175 176 #E9AFB0
#> 5         5 213 199 179 #D5C7B3

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.
Health stats visible at Monitor.