colour.models.log_encoding_SLog3

colour.models.log_encoding_SLog3(x, bit_depth=10, out_normalised_code_value=True, in_reflection=True)[source]

Defines the Sony S-Log3 log encoding curve / opto-electronic transfer function.

Parameters
  • x (numeric or array_like) – Reflection or \(IRE / 100\) input light level \(x\) to a camera.

  • bit_depth (int, optional) – Bit depth used for conversion.

  • out_normalised_code_value (bool, optional) – Whether the non-linear Sony S-Log3 data \(y\) is encoded as normalised code values.

  • in_reflection (bool, optional) – Whether the light level \(x\) to a camera is reflection.

Returns

Non-linear Sony S-Log3 data \(y\).

Return type

numeric or ndarray

Notes

Domain

Scale - Reference

Scale - 1

x

[0, 1]

[0, 1]

Range

Scale - Reference

Scale - 1

y

[0, 1]

[0, 1]

References

[SonyCorporationc]

Examples

>>> log_encoding_SLog3(0.18)  
0.4105571...

The values of S-Log3 10bit code values (18%, 90%) table in [SonyCorporationc] are obtained as follows:

>>> x = np.array([0, 18, 90]) / 100
>>> np.around(log_encoding_SLog3(x, 10, False) * 100).astype(np.int)
array([ 4, 41, 61])
>>> np.around(log_encoding_SLog3(x) * (2 ** 10 - 1)).astype(np.int)
array([ 95, 420, 598])