colour.xy_to_xyY

colour.xy_to_xyY(xy: ArrayLike, Y: Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1] = 1) → Annotated[ndarray[tuple[Any, ...], dtype[float16 | float32 | float64]], 1]

Convert from CIE xy chromaticity coordinates to CIE xyY colourspace by extending the array’s last dimension with the specified \(Y\) luminance.

xy argument with last dimension equal to 3 will be assumed to be a CIE xyY colourspace array and will be returned directly by the definition.

Parameters:

• xy (ArrayLike) – CIE xy chromaticity coordinates or CIE xyY colourspace array.

• Y (Annotated[_Buffer | _SupportsArray[dtype[Any]] | _NestedSequence[_SupportsArray[dtype[Any]]] | complex | bytes | str | _NestedSequence[complex | bytes | str], 1]) – Optional \(Y\) luminance value used to construct the CIE xyY colourspace array. The default \(Y\) luminance value is 1.

Returns:

CIE xyY colourspace array.

Return type:

numpy.ndarray

Notes

Domain	Scale - Reference	Scale - 1
xy	1	1
Y	1	1

Range	Scale - Reference	Scale - 1
xyY	1	1

• This definition is a convenient object provided to implement support of illuminant argument luminance value in various colour.models package objects such as colour.Lab_to_XYZ() or colour.Luv_to_XYZ().

References

[CIET14804f], [Wikipedia05d]

Examples

>>> xy = np.array([0.54369557, 0.32107944])
>>> xy_to_xyY(xy)
array([ 0.5436955...,  0.3210794...,  1.        ])
>>> xy = np.array([0.54369557, 0.32107944, 1.00000000])
>>> xy_to_xyY(xy)
array([ 0.5436955...,  0.3210794...,  1.        ])
>>> xy = np.array([0.54369557, 0.32107944])
>>> xy_to_xyY(xy, 100)
array([   0.5436955...,    0.3210794...,  100.        ])