colorSpec: displayRGB – R documentation

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displayRGB

Compute Display RGB from Linear RGB

Description

All RGB displays have a non-linear "gamma function" of some sort. This function converts from linear RGB to an RGB appropriate for the gamma function of the display; which is also called the electro-optical conversion function (EOCF).

Usage

DisplayRGBfromLinearRGB( RGB, gamma='sRGB' )

Arguments

`RGB`	linear RGB values organized as a vector or matrix of any size; all 3 channels are treated the same way so size does not matter
`gamma`	either the string `'sRGB'` or a positive number giving the gamma of the display.

Value

The function first clamps the input RGB to the interval [0,1]. If gamma='sRGB' (not case-sensitive) it then maps [0,1] to [0,1] using the special piecewise-defined sRGB function, see Wikipedia. In case gamma is a positive number, the function raises all values to the power 1/gamma. The dimensions and names of the input are copied to the output.
In case of error, the function returns the clamped input values.

WARNING

This function is deprecated. New software should use spacesRGB::SignalRGBfromLinearRGB() instead.

Source

Wikipedia. sRGB. http://en.wikipedia.org/wiki/sRGB

Examples

DisplayRGBfromLinearRGB( c(0.2, 0.5) )
# [1] 0.4845292 0.7353570     #  this is display sRGB, in [0,1]

DisplayRGBfromLinearRGB( c(-0.1, 0.2, 0.5, 1), 2.2 )
# [1] 0.0000000 0.4811565 0.7297401 1.0000000    #  gamma=2.2

x = seq( 0, 1, len=101)
plot( x, DisplayRGBfromLinearRGB(x), type='l' )

colorSpec

Color Calculations with Emphasis on Spectral Data

v1.2-1

GPL (>= 3)

Authors

Glenn Davis [aut, cre]

Initial release

2020-04-01