diff --git a/NEWS.md b/NEWS.md index ce47da07..ebf8c189 100644 --- a/NEWS.md +++ b/NEWS.md @@ -1,4 +1,5 @@ # aqp 2.1.0 (2024-10-16) + * CRAN release * added Munsell values of 8.5 and 9.5 to Munsell look up table and (interpolated) reference spectra (#318) * `munsell2rgb()` now safely selects the closest Munsell value and chroma to those available in the package LUT * new function `soilTextureColorPal()` for suggesting a color palette suitable for soil texture class diff --git a/vignettes/Munsell-color-conversion.Rmd b/vignettes/Munsell-color-conversion.Rmd index 5d608c34..7542781c 100644 --- a/vignettes/Munsell-color-conversion.Rmd +++ b/vignettes/Munsell-color-conversion.Rmd @@ -30,11 +30,11 @@ Soil color is most often described using the [Munsell color system](https://en.w ## Color Conversion Functions -Conversion of Munsell notation to "something" that can be displayed on-screen (sRGB color representation) is probably the most common color transformation applied to soil morphology data. The `munsell2rgb()` function is convenient for this operation when Munsell notation has been split into vectors of hue, value, and chroma. These could be columns in a `data.frame` or separate vectors. The `parseMunsell()` function is convenient when a full Munsell notation is given as a character vector. Note that `parseMunsell()` is a simplified wrapper to `munsell2rgb()`. For example, converting `10YR 4/6` with either function can return: +Conversion of Munsell notation to "something" that can be displayed on-screen (sRGB color representation) is probably the most common color transformation applied to soil morphology data. The `munsell2rgb()` function is convenient for this operation when Munsell notation has been split into vectors of hue, value, and chroma. These could be columns in a `data.frame` or separate vectors. The `parseMunsell()` function is convenient when a full Munsell notation is given as a character vector. Note that `parseMunsell()` is a wrapper to `munsell2rgb()`. For example, converting `10YR 4/6` with either function can return: * hex-notation of a color: `#805921FF`, or * sRGB color coordinates: `0.5002233 0.3489249 0.1287694`, or - * CIELAB color coordinates: `40.95021 10.31088 37.49513` + * CIELAB color coordinates: `40.95021 10.31088 37.49513`. Selection of the closest `n` Munsell color "chips", given sRGB or CIELAB colorspace coordinates is performed with the `col2Munsell()` function. Input to this function can be colorspace coordinates, named colors (e.g. `red`), or hex-notation of a color. For example, the selection of the closest Munsell chip for CIELAB coordinates `(51.4337, 9.917916, 38.6889)` results in `10YR 5/6` with a reported sigma (error) of `1.5e-6`. This error is estimated as the [CIE2000 distance](https://en.wikipedia.org/wiki/Color_difference#CIEDE2000) between the source CIELAB coordinates and the CIELAB coordinates of the closest Munsell chip. @@ -87,3 +87,5 @@ getClosestMunsellChip('3.3YR 4.4/6.1', convertColors = FALSE) ``` + +