colour.CAM_Specification_ATD95#

class colour.CAM_Specification_ATD95(h: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, C: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, Q: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, A_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, T_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, D_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, A_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, T_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, D_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>)[source]#

Define the ATD (1995) colour vision model specification.

This specification provides a standardized interface for the ATD (1995) model with field names consistent across all colour appearance models in colour.appearance. While the field names differ from the original Fairchild (2013) reference notation, they map directly to the model’s perceptual correlates.

Parameters:

  • h (float | NDArrayFloat | None) – Hue angle \(H\) in degrees.

  • C (float | NDArrayFloat | None) – Correlate of saturation \(C\). Guth (1995) incorrectly uses the terms saturation and chroma interchangeably. However, \(C\) represents a measure of saturation rather than chroma since it is measured relative to the achromatic response for the stimulus rather than that of a similarly illuminated white.

  • Q (float | NDArrayFloat | None) – Correlate of brightness \(Br\).

  • A_1 (float | NDArrayFloat | None) – First stage \(A_1\) response.

  • T_1 (float | NDArrayFloat | None) – First stage \(T_1\) response.

  • D_1 (float | NDArrayFloat | None) – First stage \(D_1\) response.

  • A_2 (float | NDArrayFloat | None) – Second stage \(A_2\) response.

  • T_2 (float | NDArrayFloat | None) – Second stage \(T_2\) response.

  • D_2 (float | NDArrayFloat | None) – Second stage \(D_2\) response.

Notes

  • This specification is the one used in the current model implementation.

References

[Fai13e], [Gut95]

__init__(h: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, C: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, Q: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, A_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, T_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, D_1: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, A_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, T_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>, D_2: float | TypeAliasForwardRef('NDArrayFloat') | None = <factory>) → None#
Parameters:

  • h (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • C (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • Q (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • A_1 (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • T_1 (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • D_1 (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • A_2 (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • T_2 (float | TypeAliasForwardRef('NDArrayFloat') | None)

  • D_2 (float | TypeAliasForwardRef('NDArrayFloat') | None)

Return type:

None

Methods

__init__(h, C, Q, A_1, T_1, D_1, A_2, T_2, D_2)

arithmetical_operation(a, operation[, in_place])

Perform the specified arithmetical operation with the \(a\) operand on the dataclass-like class.

Attributes

fields

Getter for the fields of the dataclass-like class.

items

Getter for the dataclass-like class items, i.e., the field names and values.

keys

Getter for the dataclass-like class keys, i.e., the field names.

values

Getter for the dataclass-like class field values.

h

C

Q

A_1

T_1

D_1

A_2

T_2

D_2