# colour.models.cie_ucs Module¶

## CIE UCS Colourspace¶

Defines the CIE UCS colourspace transformations:

References

 [1] http://en.wikipedia.org/wiki/CIE_1960_color_space (Last accessed 24 February 2014)
colour.models.cie_ucs.XYZ_to_UCS(XYZ)[source]

Converts from CIE XYZ colourspace to CIE UCS colourspace.

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

Notes

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

References

 [2] http://en.wikipedia.org/wiki/CIE_1960_color_space#Relation_to_CIEXYZ (Last accessed 24 February 2014)

Examples

>>> XYZ = np.array([0.1180583421, 0.1034, 0.0515089229])
>>> XYZ_to_UCS(XYZ)
array([ 0.0787055...,  0.1034    ,  0.1218252...])

colour.models.cie_ucs.UCS_to_XYZ(UVW)[source]

Converts from CIE UCS colourspace to CIE XYZ colourspace.

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

Notes

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

References

 [3] http://en.wikipedia.org/wiki/CIE_1960_color_space#Relation_to_CIEXYZ (Last accessed 24 February 2014)

Examples

>>> UCS = np.array([0.07870556, 0.1034, 0.12182529])
>>> UCS_to_XYZ(UCS)
array([ 0.1180583...,  0.1034    ,  0.0515089...])

colour.models.cie_ucs.UCS_to_uv(UVW)[source]

Returns the uv chromaticity coordinates from given CIE UCS colourspace matrix.

Parameters: UVW (array_like, (3,)) – CIE UCS colourspace matrix. uv chromaticity coordinates. tuple

Notes

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

References

 [4] http://en.wikipedia.org/wiki/CIE_1960_color_space#Relation_to_CIEXYZ (Last accessed 24 February 2014)

Examples

>>> UCS = np.array([0.1180583421, 0.1034, 0.0515089229])
>>> UCS_to_uv(UCS)
(0.4324999..., 0.3788000...)

colour.models.cie_ucs.UCS_uv_to_xy(uv)[source]

Returns the xy chromaticity coordinates from given CIE UCS colourspace uv chromaticity coordinates.

Parameters: uv (array_like) – CIE UCS uv chromaticity coordinates. xy chromaticity coordinates. tuple

Notes

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

References

 [5] http://en.wikipedia.org/wiki/CIE_1960_color_space#Relation_to_CIEXYZ (Last accessed 24 February 2014)

Examples

>>> uv = (0.43249999995420696, 0.378800000065942)
>>> UCS_uv_to_xy(uv)
(0.7072386..., 0.4129510...)