# 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=(0.34567, 0.3585))[source]

Converts from CIE XYZ colourspace to CIE Luv colourspace.

Parameters: XYZ (array_like, (3,)) – CIE XYZ colourspace matrix. illuminant (array_like, optional) – Reference illuminant chromaticity coordinates. CIE Luv colourspace matrix. ndarray, (3,)

Notes

• Input CIE XYZ colourspace matrix is in domain [0, 1].
• Input illuminant chromaticity coordinates are in domain [0, 1].
• Output $$L^*$$ is in domain [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, 0.1008, 0.09558313])
>>> XYZ_to_Luv(XYZ)
array([ 37.9856291..., -28.7922944...,  -1.3558195...])

colour.models.cie_luv.Luv_to_XYZ(Luv, illuminant=(0.34567, 0.3585))[source]

Converts from CIE Luv colourspace to CIE XYZ colourspace.

Parameters: Luv (array_like, (3,)) – CIE Luv colourspace matrix. illuminant (array_like, optional) – Reference illuminant chromaticity coordinates. CIE XYZ colourspace matrix. ndarray, (3,)

Notes

• Input $$L^*$$ is in domain [0, 100].
• Input illuminant chromaticity coordinates are in domain [0, 1].
• Output CIE XYZ colourspace matrix is in domain [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, -28.79229446, -1.3558195])
>>> Luv_to_XYZ(Luv)
array([ 0.0704953...,  0.1008    ,  0.0955831...])

colour.models.cie_luv.Luv_to_uv(Luv, illuminant=(0.34567, 0.3585))[source]

Returns the $$uv^p$$ chromaticity coordinates from given CIE Luv colourspace matrix.

Parameters: Luv (array_like, (3,)) – CIE Luv colourspace matrix. illuminant (array_like, optional) – Reference illuminant chromaticity coordinates. $$uv^p$$ chromaticity coordinates. tuple

Notes

• Input $$L^*$$ is in domain [0, 100].
• Output $$uv^p$$ chromaticity coordinates are in domain [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, -28.79229446, -1.3558195])
>>> Luv_to_uv(Luv)
(0.1508530..., 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. tuple

Notes

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

References

Examples

>>> uv = (0.15085309882985695, 0.48532970854318019)
>>> Luv_uv_to_xy(uv)
(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, (3,)) – CIE Luv colourspace matrix. CIE LCHuv colourspace matrix. ndarray, (3,)

Notes

• $$L^*$$ is in domain [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, -28.79229446, -1.3558195])
>>> Luv_to_LCHuv(Luv)
array([  37.9856291...,   28.8241993...,  182.6960474...])

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

Converts from CIE LCHuv colourspace to CIE Luv colourspace.

Parameters: LCHuv (array_like, (3,)) – CIE LCHuv colourspace matrix. CIE Luv colourspace matrix. ndarray, (3,)

Notes

• $$L^*$$ is in domain [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([37.9856291, 28.82419933, 182.69604747])
>>> LCHuv_to_Luv(LCHuv)
array([ 37.9856291..., -28.7922944...,  -1.3558195...])