colour.ATD95_Specification

class colour.ATD95_Specification[source]

Defines the ATD (1995) colour vision model specification.

This specification has field names consistent with the remaining colour appearance models in colour.appearance but diverge from Fairchild (2013) reference.

Parameters:
  • h (numeric or array_like) – Hue angle \(H\) in degrees.
  • C (numeric or array_like) – Correlate of saturation \(C\). Guth (1995) incorrectly uses the terms saturation and chroma interchangeably. However, \(C\) is here 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 (numeric or array_like) – Correlate of brightness \(Br\).
  • A_1 (numeric or array_like) – First stage \(A_1\) response.
  • T_1 (numeric or array_like) – First stage \(T_1\) response.
  • D_1 (numeric or array_like) – First stage \(D_1\) response.
  • A_2 (numeric or array_like) – Second stage \(A_2\) response.
  • T_2 (numeric or array_like) – Second stage \(A_2\) response.
  • D_2 (numeric or array_like) – Second stage \(D_2\) response.

Notes

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

References

[Fairchild2013v], [Guth1995a]

Create new instance of ATD95_Specification(h, C, Q, A_1, T_1, D_1, A_2, T_2, D_2)

__init__()

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__ Initialize self.
count(value)
index(value, [start, [stop]]) Raises ValueError if the value is not present.

Attributes

A_1 Alias for field number 3
A_2 Alias for field number 6
C Alias for field number 1
D_1 Alias for field number 5
D_2 Alias for field number 8
Q Alias for field number 2
T_1 Alias for field number 4
T_2 Alias for field number 7
h Alias for field number 0