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

[Fai13a], [Gut95]

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

`count`	Return number of occurrences of value.
`index`	Return first index of value.

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