# `Color.ChromaticAdaptation`

Chromatic adaptation transforms between reference whites.

Supported methods: `:xyz_scaling`, `:bradford` (default), `:von_kries`,
`:sharp`, `:cmccat2000`, `:cat02`. Matrices are from Bruce Lindbloom
(http://www.brucelindbloom.com/index.html?Eqn_ChromAdapt.html) and
the CAT02 / CMCCAT2000 literature.

All math is done with plain Elixir lists and floats; no `Nx`
dependency is required. Adaptation matrices are computed lazily and
memoised in `:persistent_term`.

# `adaptation_matrix_list`

Returns the 3x3 chromatic adaptation matrix as a list of rows.

### Arguments

* `source_illuminant` is the source reference white atom.

* `source_observer_angle` is `2` or `10`.

* `dest_illuminant` is the destination reference white atom.

* `dest_observer_angle` is `2` or `10`.

* `adaptation_method` defaults to `:bradford`.

### Returns

* A list of three three-element rows.

### Examples

    iex> m = Color.ChromaticAdaptation.adaptation_matrix_list(:D50, 2, :D65, 2)
    iex> [[a, _, _] | _] = m
    iex> Float.round(a, 4)
    0.9556

# `adaptation_methods`

# `adaptations`

# `ργβ`

Returns the `(ρ, γ, β)` cone response of a reference white under the
given adaptation method.

### Arguments

* `illuminant` is the illuminant atom.

* `observer_angle` is `2` or `10`.

* `adaptation_method` defaults to `:bradford`.

### Returns

* A `{ρ, γ, β}` tuple.

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*Consult [api-reference.md](api-reference.md) for complete listing*