spectral.reference: Standard Illuminants and Observers

In aqp: Algorithms for Quantitative Pedology

Standard Illuminants and Observers

Description

D65 and F2 standard illuminant spectral power distributions, CIE1931 Standard Observer (2 degree), and CIE1964 Supplemental Standard Observer (10 degree)

Usage

data(spectral.reference)

Format

An object of class data.frame with 71 rows and 9 columns.

References

Marcus, R.T. (1998). The Measurement of Color. In K. Nassau (Ed.), Color for Science, Art, and Technology (pp. 32-96). North-Holland.

CIE Colorimetry – Part 1: CIE standard colorimetric observers. CIES014-1/E:2006 – ISO 11664-1:2007(E)

CIE. (n.d.). CIE 15:2004 Tables Data. Retrieved from https://law.resource.org/pub/us/cfr/ibr/003/cie.15.2004.tables.xls

Examples

data("spectral.reference")

matplot(
  x = spectral.reference[, 1],
  y = spectral.reference[, c('xbar_2', 'ybar_2', 'zbar_2')],
  ylim = c(0, 2),
  type = 'l',
  lwd = 2, 
  lty = 1,
  las = 1,
  xlab = 'Wavelength (nm)',
  ylab = 'Weight | Intensity',
  main = "CIE1931 (2\u00B0) and CIE1964 (10\u00B0) Standard Observers
  D65 and F2 Illuminant Power Spectrum (rescaled / offset for clarity)",
  cex.main = 0.9
)

matlines(
  x = spectral.reference[, 1],
  y = spectral.reference[, c('xbar_10', 'ybar_10', 'zbar_10')],
  type = 'l',
  lwd = 2, 
  lty = 2,
  las = 1,
  xlab = 'Wavelength (nm)',
  ylab = 'Weight | Intensity',
  main = 'CIE1931 Standard Observer Weights\nD65 Standard Illuminant'
)

lines(
  x = spectral.reference$w,
  y = (spectral.reference$D65 / 100) + 0.33,
  lty = 1,
  col = 'royalblue'
)

lines(
  x = spectral.reference$w,
  y = (spectral.reference$F2 / 25) + 0.4,
  lty = 1,
  col = 'violet'
)

legend(
  'topright',
  legend = c('X_2', 'Y_2', 'Z_2', 'X_10', 'Y_10', 'Z_10', 'D65', 'F2'),
  col = c(1, 2, 3, 1, 2, 3, 'royalblue', 'violet'),
  lwd = c(2, 2, 2, 2, 2, 2, 1, 1),
  lty = c(1, 1, 1, 2, 2, 2, 1, 1),
  bty = 'n',
  cex = 0.85
)

aqp documentation built on Oct. 19, 2024, 5:06 p.m.