colour.models.rgb.transfer_functions.pivoted_log Module

Pivoted Log Encoding

Defines the Pivoted Log encoding:

See also

RGB Colourspaces IPython Notebook

References

[1]Sony Imageworks. (2012). make.py. Retrieved November 27, 2014, from https://github.com/imageworks/OpenColorIO-Configs/blob/master/nuke-default/make.py
colour.models.rgb.transfer_functions.pivoted_log.log_encoding_PivotedLog(x, log_reference=445, linear_reference=0.18, negative_gamma=0.6, density_per_code_value=0.002)[source]

Defines the Josh Pines style Pivoted Log log encoding curve / opto-electronic transfer function.

Parameters:
  • x (numeric or array_like) – Linear data \(x\).
  • log_reference (numeric or array_like) – Log reference.
  • linear_reference (numeric or array_like) – Linear reference.
  • negative_gamma (numeric or array_like) – Negative gamma.
  • density_per_code_value (numeric or array_like) – Density per code value.
Returns:

Non-linear data \(y\).
Return type:

numeric or ndarray

Examples

>>> log_encoding_PivotedLog(0.18)  
0.4349951...
colour.models.rgb.transfer_functions.pivoted_log.log_decoding_PivotedLog(y, log_reference=445, linear_reference=0.18, negative_gamma=0.6, density_per_code_value=0.002)[source]

Defines the Josh Pines style Pivoted Log log decoding curve / electro-optical transfer function.

Parameters:
  • y (numeric or array_like) – Non-linear data \(y\).
  • log_reference (numeric or array_like) – Log reference.
  • linear_reference (numeric or array_like) – Linear reference.
  • negative_gamma (numeric or array_like) – Negative gamma.
  • density_per_code_value (numeric or array_like) – Density per code value.
Returns:

Linear data \(x\).
Return type:

numeric or ndarray

Examples

>>> log_decoding_PivotedLog(0.434995112414467)  
0.1...