colour.models.cie_luv Module¶

CIE Luv Colourspace¶

Defines the CIE Luv colourspace transformations:

References

 [1] Wikipedia. (n.d.). CIELUV. Retrieved February 24, 2014, from http://en.wikipedia.org/wiki/CIELUV
colour.models.cie_luv.XYZ_to_Luv(XYZ, illuminant=(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. CIE Luv colourspace array. 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].

References

 [2] Lindbloom, B. (2003). XYZ to Luv. Retrieved February 24, 2014, from http://brucelindbloom.com/Eqn_XYZ_to_Luv.html

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=(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. CIE XYZ tristimulus values. 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].

References

 [3] Lindbloom, B. (2003). Luv to XYZ. Retrieved February 24, 2014, from http://brucelindbloom.com/Eqn_Luv_to_XYZ.html

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=(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. $$uv^p$$ chromaticity coordinates. 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].

References

 [4] Wikipedia. (n.d.). The forward transformation. Retrieved February 24, 2014, from http://en.wikipedia.org/wiki/CIELUV#The_forward_transformation

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. xy chromaticity coordinates. ndarray

Notes

• Input $$uv^p$$ chromaticity coordinates are in domain [0, 1].
• Output xy is in range [0, 1].

References

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. CIE LCHuv colourspace array. ndarray

Notes

• Input / output $$L^*$$ is in domain / range [0, 100].

References

 [6] Lindbloom, B. (2003). Luv to LCH(uv). Retrieved February 24, 2014, from http://www.brucelindbloom.com/Eqn_Luv_to_LCH.html

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. CIE Luv colourspace array. ndarray

Notes

• Input / output $$L^*$$ is in domain / range [0, 100].

References

 [7] Lindbloom, B. (2006). LCH(uv) to Luv. Retrieved February 24, 2014, from http://www.brucelindbloom.com/Eqn_LCH_to_Luv.html

Examples

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