Color.Luv (Color v0.4.0)

CIE 1976 L*u*v* color space.

Conversions use the Lindbloom formulas with exact CIE constants ε = 216/24389 and κ = 24389/27.

Summary

Types

t()

Functions

from_xyz(xyz)

Converts a CIE XYZ color to an L*u*v* color.

to_xyz(luv, options \\ [])

Converts an L*u*v* color to a CIE XYZ color.

Types

t()

@type t() :: %Color.Luv{
  alpha: number() | nil,
  illuminant: atom(),
  l: number() | nil,
  observer_angle: 2 | 10,
  u: number() | nil,
  v: number() | nil
}

Functions

from_xyz(xyz)

Converts a CIE XYZ color to an L*u*v* color.

Arguments

xyz is a Color.XYZ struct.

Returns

A Color.Luv struct tagged with the same illuminant and observer angle as the input xyz.

Examples

iex> xyz = %Color.XYZ{x: 0.95047, y: 1.0, z: 1.08883, illuminant: :D65, observer_angle: 2}
iex> {:ok, luv} = Color.Luv.from_xyz(xyz)
iex> {Float.round(luv.l, 3), Float.round(luv.u, 3), Float.round(luv.v, 3)}
{100.0, 0.0, 0.0}

to_xyz(luv, options \\ [])

Converts an L*u*v* color to a CIE XYZ color.

Arguments

luv is a Color.Luv struct.
options is a keyword list.

Options

:illuminant overrides the reference-white illuminant from the luv struct. Defaults to luv.illuminant.
:observer_angle overrides the observer angle. Defaults to luv.observer_angle.

Returns

A Color.XYZ struct.

Examples

iex> {:ok, xyz} = Color.Luv.to_xyz(%Color.Luv{l: 100.0, u: 0.0, v: 0.0})
iex> {Float.round(xyz.x, 4), Float.round(xyz.y, 4), Float.round(xyz.z, 4)}
{0.9505, 1.0, 1.0888}