colour.models.cie_luv Module¶

CIE Luv Colourspace¶

Defines the CIE Luv colourspace transformations:

See also

References

[1]	CIE TC 1-48. (2004). CIE 1976 uniform colour spaces. In CIE 015:2004 Colorimetry, 3rd Edition (p. 24). ISBN:978-3-901-90633-6

[2]	CIE TC 1-48. (2004). CIE 1976 uniform chromaticity scale diagram (UCS diagram). In CIE 015:2004 Colorimetry, 3rd Edition (p. 24). ISBN:978-3-901-90633-6

colour.models.cie_luv.XYZ_to_Luv(XYZ, illuminant=array([ 0.3457, 0.3585]))[source]¶

Converts from CIE XYZ tristimulus values to CIE Luv colourspace.

Parameters:	XYZ (array_like) – CIE XYZ tristimulus values. illuminant (array_like, optional) – Reference illuminant xy chromaticity coordinates or CIE xyY colourspace array.
Returns:	CIE Luv colourspace array.
Return type:	ndarray

Notes

Input CIE XYZ tristimulus values are in domain [0, 1].
Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
Output \(L^*\) is in range [0, 100].

Examples

>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313])
>>> XYZ_to_Luv(XYZ)  
array([ 37.9856291..., -28.8021959...,  -1.3580070...])

colour.models.cie_luv.Luv_to_XYZ(Luv, illuminant=array([ 0.3457, 0.3585]))[source]¶

Converts from CIE Luv colourspace to CIE XYZ tristimulus values.

Parameters:	Luv (array_like) – CIE Luv colourspace array. illuminant (array_like, optional) – Reference illuminant xy chromaticity coordinates or CIE xyY colourspace array.
Returns:	CIE XYZ tristimulus values.
Return type:	ndarray

Notes

Input \(L^*\) is in domain [0, 100].
Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
Output CIE XYZ tristimulus values are in range [0, 1].

Examples

>>> Luv = np.array([37.9856291 , -28.80219593,  -1.35800706])
>>> Luv_to_XYZ(Luv)  
array([ 0.0704953...,  0.1008    ,  0.0955831...])

colour.models.cie_luv.Luv_to_uv(Luv, illuminant=array([ 0.3457, 0.3585]))[source]¶

Returns the \(uv^p\) chromaticity coordinates from given CIE Luv colourspace array.

Parameters:	Luv (array_like) – CIE Luv colourspace array. illuminant (array_like, optional) – Reference illuminant xy chromaticity coordinates or CIE xyY colourspace array.
Returns:	\(uv^p\) chromaticity coordinates.
Return type:	ndarray

Notes

Input \(L^*\) is in domain [0, 100].
Input illuminant xy chromaticity coordinates or CIE xyY colourspace array are in domain [0, \(\infty\)].
Output \(uv^p\) chromaticity coordinates are in range [0, 1].

Examples

>>> Luv = np.array([37.9856291 , -28.80219593,  -1.35800706])
>>> Luv_to_uv(Luv)  
array([ 0.1508531...,  0.4853297...])

colour.models.cie_luv.Luv_uv_to_xy(uv)[source]¶

Returns the xy chromaticity coordinates from given CIE Luv colourspace \(uv^p\) chromaticity coordinates.

Parameters:	uv (array_like) – CIE Luv u”v” chromaticity coordinates.
Returns:	xy chromaticity coordinates.
Return type:	ndarray

Notes

References

[3]	Wikipedia. (n.d.). The reverse transformation. Retrieved from http://en.wikipedia.org/wiki/CIELUV#The_reverse_transformation

Examples

>>> uv = np.array([0.150853098829857, 0.485329708543180])
>>> Luv_uv_to_xy(uv)  
array([ 0.2641477...,  0.3777000...])

colour.models.cie_luv.Luv_to_LCHuv(Luv)[source]¶

Converts from CIE Luv colourspace to CIE LCHuv colourspace.

Parameters:	Luv (array_like) – CIE Luv colourspace array.
Returns:	CIE LCHuv colourspace array.
Return type:	ndarray

Notes

Examples

>>> Luv = np.array([37.9856291 , -28.80219593,  -1.35800706])
>>> Luv_to_LCHuv(Luv)  
array([  37.9856291...,   28.8341927...,  182.6994640...])

colour.models.cie_luv.LCHuv_to_Luv(LCHuv)[source]¶

Converts from CIE LCHuv colourspace to CIE Luv colourspace.

Parameters:	LCHuv (array_like) – CIE LCHuv colourspace array.
Returns:	CIE Luv colourspace array.
Return type:	ndarray

Notes

Examples

>>> LCHuv = np.array([37.98562910, 28.83419279, 182.69946404])
>>> LCHuv_to_Luv(LCHuv)  
array([ 37.9856291..., -28.8021959...,  -1.3580070...])