colour.models.log_encoding_FLog2#

colour.models.log_encoding_FLog2(in_r: ArrayLike, bit_depth: int = 10, out_normalised_code_value: bool = True, in_reflection: bool = True, constants: Structure = CONSTANTS_FLOG2) NDArrayFloat[source]#

Define the Fujifilm F-Log2 log encoding curve / opto-electronic transfer function.

Parameters:
  • in_r (ArrayLike) – Linear reflection data :math`in`.

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

  • out_normalised_code_value (bool) – Whether the non-linear Fujifilm F-Log2 data \(out\) is encoded as normalised code values.

  • in_reflection (bool) – Whether the light level :math`in` to a camera is reflection.

  • constants (Structure) – Fujifilm F-Log2 constants.

Returns:

Non-linear data \(out\).

Return type:

numpy.floating or numpy.ndarray

Notes

Domain

Scale - Reference

Scale - 1

in_r

[0, 1]

[0, 1]

Range

Scale - Reference

Scale - 1

out_r

[0, 1]

[0, 1]

References

[Fujifilm22b]

Examples

>>> log_encoding_FLog2(0.18)  
0.3910072...

The values of 2-2. F-Log2 Code Value table in [Fujifilm22b] are obtained as follows:

>>> x = np.array([0, 18, 90]) / 100
>>> np.around(log_encoding_FLog2(x, 10, False) * 100, 1)
array([  3.5,  38.4,  57.8])
>>> np.around(log_encoding_FLog2(x) * (2**10 - 1)).astype(np.int_)
array([ 95, 400, 570])