R: Find the Nearest Named R-Color to a Given RGB-Color

RgbToCol {DescTools} | R Documentation

## Find the Nearest Named R-Color to a Given RGB-Color

### Description

Converting a RGB-color to a named R-Color means looking for a color in the R-palette, which is nearest to the given RGB-color. This function uses the minimum of squared distance (`"euclidean"`) or the minimum absolute distance (`"manhattan"`) as proximity measure.
`RgbToLong()` converts a RGB-color to a long integer in numeric format. `LongToRGB()` does it the other way round.

### Usage

    RgbToCol(col, method = "rgb", metric = "euclidean")

    RgbToLong(col)
    LongToRgb(col)

### Arguments

`col` | the color in rgb code, say a matrix with the red, green and blue code in the rows.
`method` | character string specifying the color space to be used. Can be `"rgb"` (default) or `"hsv"`.
`metric` | character string specifying the metric to be used for calculating distances between the colors. Available options are `"euclidean"` (default) and `"manhattan"`. Euclidean distances are root sum-of-squares of differences, and manhattan distances are the sum of absolute differences.

### Details

It may not be clear from the start which method, rgb or hsv, yield the more natural results. Trying and comparing is a recommended strategy. Moreover the shortest numerical distance will not always be the best choice, when comparing the colours visually.

### Value

the name of the nearest found R color.

### Author(s)

Andri Signorell <andri@signorell.net>

### See Also

`ColToRgb` and the other conversion functions

### Examples

    RgbToCol(matrix(c(162,42,42), nrow=3))

    RgbToLong(matrix(c(162,42,42), nrow=3))

[Package DescTools version 0.99.26 Index]