View Source Ultraviolet.Color.Lab (Ultraviolet v0.1.1)

Functions for working in the CIE Lab color space.

To calculate the lightness value of a color (L), the CIE Lab color space uses a reference white point. This reference white point defines what is considered to be "white" in the color space. By default Ultraviolet uses the D65 reference point.

Possible reference points are:

:d50: Represents the color temperature of daylight at 5000K.
:d55: Represents mid-morning or mid-afternoon daylight at 5500K.
:d65: Represents average daylight at 6500K (default)
:a: Represents the color temperature of a typical incandescent light bulb at approximately 2856K.
:b: Represents noon daylight with a color temperature of approximately 4874K.
:c: Represents average or north sky daylight; it's a theoretical construct, not often used in practical applications.
:f2: Represents cool white fluorescent light.
:f7: This is a broad-band fluorescent light source with a color temperature of approximately 6500K.
:f11: This is a narrow tri-band fluorescent light source with a color temperature of approximately 4000K.
:e: Represents an equal energy white point, where all wavelengths in the visible spectrum are equally represented.
:icc

Summary

Types

t()

Defines the channels in a Lab color.

white_point()

Functions

from_rgb(color, options \\ [])

Converts from an RGB Color struct to a Lab struct.

new(channels)

Generates a new CIE Lab color.

new(l, a, b)

Generates a new CIE Lab color.

new(l, a, b, a_)

Generates a new CIE Lab color.

to_rgb(lab, options \\ [])

Converts from CIE Lab to sRGB

Types

t()

@type t() :: %Ultraviolet.Color.Lab{
  a: number(),
  a_: number(),
  b_: number(),
  l_: number()
}

Defines the channels in a Lab color.

white_point()

@type white_point() ::
  :d50 | :d55 | :d65 | :a | :b | :c | :f2 | :f7 | :f11 | :e | :icc

Functions

from_rgb(color, options \\ [])

@spec from_rgb(Ultraviolet.Color.t(), list()) :: {:ok, t()}

Converts from an RGB Color struct to a Lab struct.

Options

:reference: the CIE Lab white reference point. Default: :d65
:round: an integer if rounding L, a, and b channel values to N decimal places is desired; if no rounding is desired, pass false. Default: 2

new(channels)

@spec new(tuple() | [number()] | map() | [...]) :: {:ok, t()}

Generates a new CIE Lab color.

iex>Ultraviolet.Color.Lab.new({65.49, 64.24, -10.65})
{:ok, %Ultraviolet.Color.Lab{l_: 65.49, a_: 64.24, b_: -10.65}}

new(l, a, b)

@spec new(number(), number(), number()) :: {:ok, t()}

Generates a new CIE Lab color.

iex>Ultraviolet.Color.Lab.new(65.49, 64.24, -10.65)
{:ok, %Ultraviolet.Color.Lab{l_: 65.49, a_: 64.24, b_: -10.65}}

new(l, a, b, a_)

@spec new(number(), number(), number(), number()) :: {:ok, t()}

Generates a new CIE Lab color.

iex>Ultraviolet.Color.Lab.new(65.49, 64.24, -10.65, 0.5)
{:ok, %Ultraviolet.Color.Lab{l_: 65.49, a_: 64.24, b_: -10.65, a: 0.5}}

to_rgb(lab, options \\ [])

@spec to_rgb(t(), list()) :: {:ok, Ultraviolet.Color.t()}

Converts from CIE Lab to sRGB

Options

:reference: the CIE Lab white reference point. Default: :d65
:round: an integer if rounding r, g, and b channel values to N decimal places is desired; if no rounding is desired, pass false. Default: 0