Color.Oklab (Color v0.4.0)

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Oklab perceptual color space (Björn Ottosson, 2020).

Oklab is defined relative to CIE XYZ under the D65 reference white with Y ∈ [0, 1]. Conversions here assume the input Color.XYZ is already D65; if it is tagged with a different illuminant you should chromatically adapt it first with Color.ChromaticAdaptation.

Summary

Types

t()

Functions

from_xyz(xyz)

Converts a CIE XYZ color (D65/2°) to Oklab.

to_xyz(oklab)

Converts an Oklab color to a CIE XYZ color (D65/2°).

Types

t()

@type t() :: %Color.Oklab{
  a: number() | nil,
  alpha: number() | nil,
  b: number() | nil,
  l: number() | nil
}

Functions

from_xyz(xyz)

Converts a CIE XYZ color (D65/2°) to Oklab.

Arguments

Returns

Examples

iex> xyz = %Color.XYZ{x: 0.95047, y: 1.0, z: 1.08883, illuminant: :D65, observer_angle: 2}
iex> {:ok, oklab} = Color.Oklab.from_xyz(xyz)
iex> {Float.round(oklab.l, 3), abs(oklab.a) < 1.0e-4, abs(oklab.b) < 1.0e-4}
{1.0, true, true}

to_xyz(oklab)

Converts an Oklab color to a CIE XYZ color (D65/2°).

Arguments

Returns

Examples

iex> {:ok, xyz} = Color.Oklab.to_xyz(%Color.Oklab{l: 1.0, a: 0.0, b: 0.0})
iex> {Float.round(xyz.x, 4), Float.round(xyz.y, 4), Float.round(xyz.z, 4)}
{0.9505, 1.0, 1.0883}