# colour.colorimetry.transformations Module¶

## Colour Matching Functions Transformations¶

Defines various educational objects for colour matching functions transformations:

colour.colorimetry.transformations.RGB_2_degree_cmfs_to_XYZ_2_degree_cmfs(wavelength)[source]

Converts Wright & Guild 1931 2 Degree RGB CMFs colour matching functions into the CIE 1931 2 Degree Standard Observer colour matching functions.

Parameters: wavelength (numeric) – Wavelength $$\lambda$$ in nm. CIE 1931 2 Degree Standard Observer spectral tristimulus values. ndarray, (3,) KeyError – If wavelength $$\lambda$$ is not available in the colour matching functions.

Notes

• Data for the CIE 1931 2 Degree Standard Observer already exists, this definition is intended for educational purpose.

References

 [1] Wyszecki & Stiles, Color Science - Concepts and Methods Data and Formulae - Second Edition, Wiley Classics Library Edition, published 2000, ISBN-10: 0-471-39918-3, pages 138, 139.

Examples

>>> RGB_2_degree_cmfs_to_XYZ_2_degree_cmfs(700)
array([ 0.0113577...,  0.004102  ,  0.        ])

colour.colorimetry.transformations.RGB_10_degree_cmfs_to_XYZ_10_degree_cmfs(wavelength)[source]

Converts Stiles & Burch 1959 10 Degree RGB CMFs colour matching functions into the CIE 1964 10 Degree Standard Observer colour matching functions.

Parameters: wavelength (numeric) – Wavelength $$\lambda$$ in nm. CIE 1964 10 Degree Standard Observer spectral tristimulus values. ndarray, (3,) KeyError – If wavelength $$\lambda$$ is not available in the colour matching functions.

Notes

• Data for the CIE 1964 10 Degree Standard Observer already exists, this definition is intended for educational purpose.

References

 [2] Wyszecki & Stiles, Color Science - Concepts and Methods Data and Formulae - Second Edition, Wiley Classics Library Edition, published 2000, ISBN-10: 0-471-39918-3, page 141.

Examples

>>> RGB_10_degree_cmfs_to_XYZ_10_degree_cmfs(700)
array([  9.6432150...e-03,   3.7526317...e-03,  -4.1078830...e-06])

colour.colorimetry.transformations.RGB_10_degree_cmfs_to_LMS_10_degree_cmfs(wavelength)[source]

Converts Stiles & Burch 1959 10 Degree RGB CMFs colour matching functions into the Stockman & Sharpe 10 Degree Cone Fundamentals spectral sensitivity functions.

Parameters: wavelength (numeric) – Wavelength $$\lambda$$ in nm. Stockman & Sharpe 10 Degree Cone Fundamentals spectral tristimulus values. ndarray, (3,) KeyError – If wavelength $$\lambda$$ is not available in the colour matching functions.

Notes

• Data for the Stockman & Sharpe 10 Degree Cone Fundamentals already exists, this definition is intended for educational purpose.

References

 [3] CIE 170-1:2006 Fundamental Chromaticity Diagram with Physiological Axes - Part 1, ISBN-13: 978-3-901-90646-6

Examples

>>> RGB_10_degree_cmfs_to_LMS_10_degree_cmfs(700)
array([ 0.0052860...,  0.0003252...,  0.        ])

colour.colorimetry.transformations.LMS_2_degree_cmfs_to_XYZ_2_degree_cmfs(wavelength)[source]

Converts Stockman & Sharpe 2 Degree Cone Fundamentals colour matching functions into the CIE 2012 2 Degree Standard Observer colour matching functions.

Parameters: wavelength (numeric) – Wavelength $$\lambda$$ in nm. CIE 2012 2 Degree Standard Observer spectral tristimulus values. ndarray, (3,) KeyError – If wavelength $$\lambda$$ is not available in the colour matching functions.

Notes

• Data for the CIE 2012 2 Degree Standard Observer already exists, this definition is intended for educational purpose.

References

 [4] http://www.cvrl.org/database/text/cienewxyz/cie2012xyz2.htm (Last accessed 25 June 2014)

Examples

>>> LMS_2_degree_cmfs_to_XYZ_2_degree_cmfs(700)
array([ 0.0109677...,  0.0041959...,  0.        ])