Struct Lab

pub struct Lab;

🌌 The CIELAB color space

The CIE L*a*b* color space was created in 1976 to be more perceptually uniform than RGB color spaces, and is both widely used and the basis of other efforts to express colors, including FreieFarbe.

Its components are [L, a, b] with

• L - the lightness with a natural bound between 0 and 100, where 0 represents pure black and 100 represents the lightness of white;
• a - how green/red the color is; and
• b - how blue/yellow the color is.

a and b are unbounded, but are usually between -160 and 160.

The color space has poor hue linearity and hue uniformity compared with Oklab, though superior lightness uniformity. Note that the lightness range differs from Oklab as well; in Oklab white has a lightness of 1.

The CIE L*a*b* color space is defined in terms of a D50 white point. For conversion between color spaces with other illuminants (especially D65 as in sRGB), the standard Bradform linear chromatic adaptation transform is used.

This corresponds to the color space in CSS Color Module Level 4 § 9.1 .

Lab has a cylindrical counterpart: Lch.

Trait Implementations

impl Clone for Lab

fn clone(&self) -> Lab

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ColorSpace for Lab

const TAG: Option<ColorSpaceTag>

The tag corresponding to this color space, if a matching tag exists.

const WHITE_COMPONENTS: [f32; 3]

The component values for the color white within this color space.

fn to_linear_srgb([l, a, b]: [f32; 3]) -> [f32; 3]

Convert an opaque color to linear sRGB.

fn from_linear_srgb(src: [f32; 3]) -> [f32; 3]

Convert an opaque color from linear sRGB.

fn scale_chroma([l, a, b]: [f32; 3], scale: f32) -> [f32; 3]

Scale the chroma by the given amount.

fn convert<TargetCS: ColorSpace>(src: [f32; 3]) -> [f32; 3]

Convert to a different color space.

fn clip([l, a, b]: [f32; 3]) -> [f32; 3]

Clip the color’s components to fit within the natural gamut of the color space.

const IS_LINEAR: bool = false

Whether the color space is linear.

const LAYOUT: ColorSpaceLayout = ColorSpaceLayout::Rectangular

The layout of the color space.

const WHITE_POINT: Chromaticity = Chromaticity::D65

The white point of the color space.

fn to_linear_srgb_absolute(src: [f32; 3]) -> [f32; 3]

Convert an opaque color to linear sRGB, without chromatic adaptation.

fn from_linear_srgb_absolute(src: [f32; 3]) -> [f32; 3]

Convert an opaque color from linear sRGB, without chromatic adaptation.

fn convert_absolute<TargetCS: ColorSpace>(src: [f32; 3]) -> [f32; 3]

Convert to a different color space, without chromatic adaptation.

fn chromatically_adapt( src: [f32; 3], from: Chromaticity, to: Chromaticity, ) -> [f32; 3]

Chromatically adapt the color between the given white point chromaticities.

impl Debug for Lab

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<Lab> for ColorSpaceTag

fn from(_: Lab) -> Self

Converts to this type from the input type.

impl Copy for Lab