colour.models.cie_xyy Module¶
CIE xyY Colourspace¶
Defines the CIE xyY colourspace transformations:
See also
References
[1] | Wikipedia. (n.d.). CIE 1931 color space. Retrieved February 24, 2014, from http://en.wikipedia.org/wiki/CIE_1931_color_space |
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colour.models.cie_xyy.
XYZ_to_xyY
(XYZ, illuminant=(0.34567, 0.3585))[source]¶ Converts from CIE XYZ tristimulus values to CIE xyY colourspace and reference illuminant.
Parameters: - XYZ (array_like) – CIE XYZ tristimulus values.
- illuminant (array_like, optional) – Reference illuminant chromaticity coordinates.
Returns: CIE xyY colourspace array.
Return type: ndarray
Notes
- Input CIE XYZ tristimulus values are in domain [0, 1].
- Output CIE xyY colourspace array 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, 0.10080000, 0.09558313]) >>> XYZ_to_xyY(XYZ) array([ 0.2641477..., 0.3777000..., 0.1008 ])
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colour.models.cie_xyy.
xyY_to_XYZ
(xyY)[source]¶ Converts from CIE xyY colourspace to CIE XYZ tristimulus values.
Parameters: xyY (array_like) – CIE xyY colourspace array. Returns: CIE XYZ tristimulus values. Return type: ndarray Notes
- Input CIE xyY colourspace array is in domain [0, 1].
- Output CIE XYZ tristimulus values are 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, 0.10080000]) >>> xyY_to_XYZ(xyY) array([ 0.0704953..., 0.1008 , 0.0955831...])
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colour.models.cie_xyy.
xy_to_xyY
(xy, Y=1)[source]¶ Converts from xy chromaticity coordinates to CIE xyY colourspace by extending the array last dimension with \(Y\) Luminance.
xy argument with last dimension being equal to 3 will be assumed to be a CIE xyY colourspace array argument and will be returned directly by the definition.
Parameters: - xy (array_like) – xy chromaticity coordinates or CIE xyY colourspace array.
- Y (numeric, optional) – Optional \(Y\) Luminance value used to construct the CIE xyY colourspace array, otherwise the \(Y\) Luminance will be set to 1.
Returns: CIE xyY colourspace array.
Return type: ndarray
See also
Notes
- This definition is a convenient object provided to implement support of
illuminant argument luminance value in various
colour.models
package objects such ascolour.models.Lab_to_XYZ()
orcolour.models.Luv_to_XYZ()
. - Input xy chromaticity coordinates are in domain [0, 1].
- Output CIE xyY colourspace array is in domain [0, 1].
Examples
>>> xy = np.array([0.26414772, 0.37770001]) >>> xy_to_xyY(xy) array([ 0.2641477..., 0.3777000..., 1. ]) >>> xy = np.array([0.26414772, 0.37770001, 0.10080000]) >>> xy_to_xyY(xy) array([ 0.2641477..., 0.3777000..., 0.1008...]) >>> xy = np.array([0.26414772, 0.37770001]) >>> xy_to_xyY(xy, 100) array([ 0.2641477..., 0.3777000..., 100. ])
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colour.models.cie_xyy.
xyY_to_xy
(xyY)[source]¶ Converts from CIE xyY colourspace to xy chromaticity coordinates.
xyY argument with last dimension being equal to 2 will be assumed to be a xy chromaticity coordinates argument and will be returned directly by the definition.
Parameters: xyY (array_like) – CIE xyY colourspace array or xy chromaticity coordinates. Returns: xy chromaticity coordinates. Return type: ndarray See also
Notes
- Input CIE xyY colourspace array is in domain [0, 1].
- Output xy chromaticity coordinates are in domain [0, 1].
Examples
>>> xyY = np.array([0.26414772, 0.37770001, 0.10080000]) >>> xyY_to_xy(xyY) array([ 0.2641477..., 0.3777000...]) >>> xy = np.array([0.26414772, 0.37770001]) >>> xyY_to_xy(xy) array([ 0.2641477..., 0.3777000...])
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colour.models.cie_xyy.
xy_to_XYZ
(xy)[source]¶ Returns the CIE XYZ tristimulus values from given xy chromaticity coordinates.
Parameters: xy (array_like) – xy chromaticity coordinates. Returns: CIE XYZ tristimulus values. Return type: ndarray Notes
- Input xy chromaticity coordinates are in domain [0, 1].
- Output CIE XYZ tristimulus values are in domain [0, 1].
Examples
>>> xy = np.array([0.26414772236966133, 0.37770000704815188]) >>> xy_to_XYZ(xy) array([ 0.6993585..., 1. , 0.9482453...])
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colour.models.cie_xyy.
XYZ_to_xy
(XYZ, illuminant=(0.34567, 0.3585))[source]¶ Returns the xy chromaticity coordinates from given CIE XYZ tristimulus values.
Parameters: - XYZ (array_like) – CIE XYZ tristimulus values.
- illuminant (array_like, optional) – Reference illuminant chromaticity coordinates.
Returns: xy chromaticity coordinates.
Return type: ndarray
Notes
- Input CIE XYZ tristimulus values are in domain [0, 1].
- Output xy chromaticity coordinates are in domain [0, 1].
Examples
>>> XYZ = np.array([0.07049534, 0.10080000, 0.09558313]) >>> XYZ_to_xy(XYZ) array([ 0.2641477..., 0.3777000...])