colour.XYZ_to_hdr_IPT#

colour.XYZ_to_hdr_IPT(XYZ: ArrayLike, Y_s: ArrayLike = 0.2, Y_abs: ArrayLike = 100, method: Literal['Fairchild 2011', 'Fairchild 2010'] | str = 'Fairchild 2011') → NDArrayFloat[source]#

Convert from CIE XYZ tristimulus values to hdr-IPT colourspace.

Parameters:

XYZ (ArrayLike) – CIE XYZ tristimulus values.
Y_s (ArrayLike) – Relative luminance \(Y_s\) of the surround.
Y_abs (ArrayLike) – Absolute luminance \(Y_{abs}\) of the scene diffuse white in \(cd/m^2\).
method (Literal['Fairchild 2011', 'Fairchild 2010'] | str) – Computation method.

Returns:

hdr-IPT colourspace array.

Return type:

numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
`XYZ`	[0, 1]	[0, 1]
`Y_s`	[0, 1]	[0, 1]

Range	Scale - Reference	Scale - 1
`IPT_hdr`	`I_hdr` : [0, 100] `P_hdr` : [-100, 100] `T_hdr` : [-100, 100]	`I_hdr` : [0, 1] `P_hdr` : [-1, 1] `T_hdr` : [-1, 1]

Range

Scale - Reference

Scale - 1

IPT_hdr

I_hdr : [0, 100]

P_hdr : [-100, 100]

T_hdr : [-100, 100]

I_hdr : [0, 1]

P_hdr : [-1, 1]

T_hdr : [-1, 1]

Input CIE XYZ tristimulus values must be adapted to CIE Standard Illuminant D Series D65.

References

[FW10], [FC11]

Examples

>>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952])
>>> XYZ_to_hdr_IPT(XYZ)  
array([ 48.3937634...,  42.4499020...,  22.0195403...])
>>> XYZ_to_hdr_IPT(XYZ, method="Fairchild 2010")  
array([ 30.0287314...,  83.9384506...,  34.9028738...])