xyYtoMunsell {munsellinterpol} | R Documentation |
Convert xyY coordinates to Munsell HVC
Description
xyYtoMunsell
Convert xyY coordinates to Munsell HVC,
by interpolating over the extrapolated Munsell renotation data
Usage
xyYtoMunsell( xyY, xyC='NBS', hcinterp='bicubic', vinterp='cubic',
VfromY='ASTM', warn=TRUE, perf=FALSE )
Arguments
xyY |
a numeric Nx3 matrix with CIE xyY coordinates in the rows, or a vector that can be converted to such a matrix, by row. These are for viewing in an environment with Illuminant C, with Y=100. |
xyC |
a numeric 2-vector with xy chromaticity of Illuminant C.
It can also be one of the strings given in |
hcinterp |
either |
vinterp |
either |
VfromY |
passed as the parameter |
warn |
if an xyY cannot be mapped
(usually because the root finder has wandered afar),
its H and V are set to |
perf |
if |
Details
See MunsellToxyY()
and the User Guide - Appendix C.
Value
a data.frame
with N rows and these columns:
xyY |
The input xyY |
HVC |
the computed HVC. H is automatically wrapped to (0,100]. In case of failure, H and C are set to |
SAMPLE_NAME |
the Munsell notation for HVC, a character vector |
If perf
is TRUE
then there are these additional columns:
time.elapsed |
elapsed time in seconds. If available, the function |
iterations |
the number of iterations of |
evalations |
the number of forward (HVC → xyY) function evaluations |
estim.precis |
the estimated precision from |
Warning
Even when vinterp='cubic'
the function xyY → HVC is not C^1
on the plane V=1.
This is because of a change in Value spacing:
when V\ge
1 the Value spacing is 1, but when V\le
1 the Value spacing is 0.2.
Author(s)
Jose Gama and Glenn Davis
Source
Paul Centore 2014
The Munsell and Kubelka-Munk Toolbox
https://www.munsellcolourscienceforpainters.com/MunsellAndKubelkaMunkToolbox/MunsellAndKubelkaMunkToolbox.html
https://www.rit.edu/science/munsell-color-lab
https://www.rit-mcsl.org/MunsellRenotation/all.dat
https://www.rit-mcsl.org/MunsellRenotation/real.dat
References
Judd, Deane B. The 1931 I.C.I. Standard Observer and Coordinate System for Colorimetry. Journal of the Optical Society of America. Vol. 23. pp. 359-374. October 1933.
Newhall, Sidney M., Dorothy Nickerson, Deane B. Judd. Final Report of the O.S.A. Subcommitte on the Spacing of the Munsell Colors. Journal of the Optical Society of America. Vol. 33. No. 7. pp. 385-418. July 1943.
Kelly, Kenneth L. Kasson S. Gibson. Dorothy Nickerson. Tristimulus Specification of the Munsell Book of Color from Spectrophometric Measurements National Bureau of Standards RP1549 Volume 31. August 1943.
Judd, Deane B. and Günther Wyszecki. Extension of the Munsell Renotation System to Very Dark Colors. Journal of the Optical Society of America. Vol. 46. No. 4. pp. 281-284. April 1956.
Paul Centore 2014 The Munsell and Kubelka-Munk Toolbox https://www.munsellcolourscienceforpainters.com/MunsellAndKubelkaMunkToolbox/MunsellAndKubelkaMunkToolbox.html
See Also
MunsellToxyY()
,
rootSolve::multiroot()
,
microbenchmark::get_nanotime()
Examples
xyYtoMunsell(c(0.310897, 0.306510, 74.613450))
## xyY.1 xyY.2 xyY.3 HVC.H HVC.V HVC.C SAMPLE_NAME
## 1 0.310897 0.306510 74.613450 87.541720 8.900000 2.247428 7.5P 8.9/2.2