colour.models.cie_xyy Module¶

CIE xyY Colourspace¶

Defines the CIE xyY colourspace transformations:

References

 [1] Wikipedia. (n.d.). CIE 1931 color space. Retrieved February 24, 2014, from http://en.wikipedia.org/wiki/CIE_1931_color_space
colour.models.cie_xyy.XYZ_to_xyY(XYZ, illuminant=(0.34567, 0.3585))[source]

Converts from CIE XYZ colourspace to CIE xyY colourspace and reference illuminant.

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

Notes

• Input CIE XYZ colourspace matrix is in domain [0, 1].
• Output CIE xyY colourspace matrix is in domain [0, 1].

References

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

Examples

>>> XYZ = np.array([0.07049534, 0.1008, 0.09558313])
>>> XYZ_to_xyY(XYZ)
array([ 0.2641477...,  0.3777000...,  0.1008    ])

colour.models.cie_xyy.xyY_to_XYZ(xyY)[source]

Converts from CIE xyY colourspace to CIE XYZ colourspace.

Parameters: xyY (array_like, (3,)) – CIE xyY colourspace matrix. CIE XYZ colourspace matrix. ndarray, (3,)

Notes

• Input CIE xyY colourspace matrix is in domain [0, 1].
• Output CIE XYZ colourspace matrix is in domain [0, 1].

References

 [3] Lindbloom, B. (2009). xyY to XYZ. Retrieved February 24, 2014, from http://www.brucelindbloom.com/Eqn_xyY_to_XYZ.html

Examples

>>> xyY = np.array([0.26414772, 0.37770001, 0.1008])
>>> xyY_to_XYZ(xyY)
array([ 0.0704953...,  0.1008    ,  0.0955831...])

colour.models.cie_xyy.xy_to_XYZ(xy)[source]

Returns the CIE XYZ colourspace matrix from given xy chromaticity coordinates.

Parameters: xy (array_like) – xy chromaticity coordinates. CIE XYZ colourspace matrix. ndarray, (3,)

Notes

• Input xy chromaticity coordinates are in domain [0, 1].
• Output CIE XYZ colourspace matrix is in domain [0, 1].

Examples

>>> xy = (0.26414772236966133, 0.37770000704815188)
>>> xy_to_XYZ(xy)
array([ 0.6993585...,  1.        ,  0.9482453...])

colour.models.cie_xyy.XYZ_to_xy(XYZ, illuminant=(0.34567, 0.3585))[source]

Returns the xy chromaticity coordinates from given CIE XYZ colourspace matrix.

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

Notes

• Input CIE XYZ colourspace matrix is in domain [0, 1].
• Output xy chromaticity coordinates are in domain [0, 1].

Examples

>>> XYZ = np.array([0.07049534, 0.1008, 0.09558313])
>>> XYZ_to_xy(XYZ)
(0.2641477..., 0.3777000...)