Color.Rec2020 (Color v0.11.0)

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ITU-R BT.2020 / Rec. 2020 color space, using the Rec. 2020 wide-gamut primaries (D65 reference white) and the BT.2020 SDR opto-electronic transfer function at 12-bit precision.

Rec. 2020 is the wide-gamut color space standardised for UHDTV and is the basis for HDR signalling in BT.2100 (with PQ or HLG encoding). Its primaries enclose a substantially larger portion of the visible spectral locus than sRGB or P3.

Channels r, g and b are unit floats in the nominal range [0, 1].

Summary

Types

t()

Functions

from_xyz(xyz)

Converts a CIE XYZ color (assumed D65/2°) to Rec. 2020.

to_xyz(rec2020)

Converts a Rec. 2020 color to a CIE XYZ color.

Types

t()

@type t() :: %Color.Rec2020{
  alpha: number() | nil,
  b: number() | nil,
  g: number() | nil,
  r: number() | nil
}

Functions

from_xyz(xyz)

@spec from_xyz(Color.XYZ.t()) :: {:ok, t()}

Converts a CIE XYZ color (assumed D65/2°) to Rec. 2020.

Arguments

Returns

Examples

iex> xyz = %Color.XYZ{x: 0.95047, y: 1.0, z: 1.08883, illuminant: :D65, observer_angle: 2}
iex> {:ok, rec} = Color.Rec2020.from_xyz(xyz)
iex> {Float.round(rec.r, 3), Float.round(rec.g, 3), Float.round(rec.b, 3)}
{1.0, 1.0, 1.0}

to_xyz(rec2020)

@spec to_xyz(t()) :: {:ok, Color.XYZ.t()}

Converts a Rec. 2020 color to a CIE XYZ color.

Arguments

Returns

  • A Color.XYZ struct tagged with D65/2°, Y ∈ [0, 1].

Examples

iex> {:ok, xyz} = Color.Rec2020.to_xyz(%Color.Rec2020{r: 1.0, g: 1.0, b: 1.0})
iex> {Float.round(xyz.x, 4), Float.round(xyz.y, 4), Float.round(xyz.z, 4)}
{0.9505, 1.0, 1.0888}