plenoptic.regularize.penalize_range#

plenoptic.regularize.penalize_range(img, allowed_range=(0.0, 1.0), **kwargs)[source]#

Calculate quadratic penalty on values outside of allowed_range.

Provides a ‘soft’ pixel-range regularization by imposing a quadratic penalty on any values outside the allowed_range. All values within the allowed_range have a penalty of 0.

To use as a penalty_function in synthesis methods, functools.partial must be used to fix the allowed_range (see Examples).

Parameters:

  • img (Tensor) – The tensor to penalize.

  • allowed_range (tuple[float, float] (default: (0.0, 1.0))) – 2-tuple of values giving the (min, max) allowed values.

  • **kwargs (Any) – Ignored, only present to absorb extra arguments.

Return type:

Tensor

Returns:

penalty – Penalty for values outside range.

Examples

Initialize metamer with allowed range (0.2, 0.8):

>>> import plenoptic as po
>>> img = po.data.einstein()
>>> model = po.models.Gaussian(30).eval()
>>> po.remove_grad(model)
>>> # Make function penalizing values outside (0.2, 0.8)
>>> def custom_range(x):
...     penalty = po.regularize.penalize_range(x, allowed_range=(0.2, 0.8))
...     return penalty
>>> met_default = po.Metamer(img, model)
>>> met_custom = po.Metamer(img, model, penalty_function=custom_range)
>>> # Compare the value of the penalties
>>> met_default.penalty_function(img)
tensor(0.)
>>> met_custom.penalty_function(img)
tensor(49.3881)