sRGBtoMunsell {munsellinterpol}

Convert sRGB coordinates to Munsell HVC

Description

Converts non-linear sRGB coordinates to Munsell HVC, by interpolating over the extrapolated Munsell renotation data

Usage

sRGBtoMunsell( sRGB, maxSignal=255, ... ) 

Arguments

sRGB

a numeric Nx3 matrix with signal sRGB coordinates in the rows, or a vector that can be converted to such a matrix, by row. These are non-linear signal values, but they are not required to be integers.

maxSignal

maximum value of signal sRGB. Other popular values are 1, 100, 1023, and 65535. Even when 1, they are still taken to be non-linear signal values.

...

other parameters passed to XYZtoMunsell()

Details

The conversion is done in these steps:

• sRGB → XYZ using spacesXYZ::XYZfromRGB() with the given maxSignal

• XYZ is adapted from Illuminant D65 (from the sRGB standard) to Illuminant C, using spacesXYZ::adaptXYZ() with the Bradford chromatic adaptation method

• XYZ → HVC using XYZtoMunsell() and the given ...

Value

a numeric Nx3 matrix with HVC coordinates in the rows. The rownames are copied from input to output, unless the rownames are NULL when they are set to the Munsell notations for HVC.
In case of error, it returns NULL.

Note

The more general function RGBtoMunsell() also performs this conversion. This function has the advantage that it takes a little less time, since the CAT (using the Bradford method) is precomputed during base::.onLoad(). But it has the disadvantage that the chromatic adaptation method cannot be changed.

Author(s)

Jose Gama and Glenn Davis

References

Wikipedia. sRGB. https://en.wikipedia.org/wiki/SRGB.

Paul Centore 2014 The Munsell and Kubelka-Munk Toolbox https://www.munsellcolourscienceforpainters.com/MunsellAndKubelkaMunkToolbox/MunsellAndKubelkaMunkToolbox.html

See Also

RGBtoMunsell(), XYZtoMunsell(), spacesXYZ::CAT(), spacesXYZ::adaptXYZ(), spacesXYZ::XYZfromRGB()

Examples

sRGBtoMunsell( c(255,45,67) )
##                     H        V        C
##  5.4R 5.5/18 5.401135 5.477315 18.01984

sRGBtoMunsell( c(1,0,1), maxSignal=1 )
##                 H        V        C
##  8P 6/26 87.98251 5.981297 25.64534