native_encoding: Convert to and from the R native colour representation

In farver: High Performance Colour Space Manipulation

Convert to and from the R native colour representation

Description

Colours in R are internally encoded as integers when they are passed around to graphics devices. The encoding splits the 32 bit in the integer between red, green, blue, and alpha, so that each get 8 bit, equivalent to 256 values. It is very seldom that an R user is subjected to this representation, but it is present in the nativeRaster format which can be obtained from e.g. capturing the content of a graphic device (using dev.capture()) or reading in PNG files using png::readPNG(native = TRUE). It is very rare that you might need to convert back and forth between this format, but it is provided here for completeness.

Usage

encode_native(colour, ...)

decode_native(colour)

Arguments

colour	For encode_native either a vector of hex-encoded colours/colour names or a matrix encoding colours in any of the supported colour spaces. If the latter, the colours will be encoded to a hex string using encode_colour() first. For decode_native it is a vector of integers.
...	Arguments passed on to encode_colour()

Value

encode_native() returns an integer vector and decode_native() returns a character vector, both matching the length of the input.

Examples

# Get native representation of navyblue and #228B22
native_col <- encode_native(c('navyblue', '#228B22'))
native_col

# Convert back
decode_native(native_col)

farver documentation built on May 29, 2024, 5:21 a.m.