RandomScalePerturber

class nrtk.impls.perturb_image.geometric.random.RandomScalePerturber(*, limit: float | tuple[float, float] = 0.0, interpolation: int = 1, probability: float = 1.0, seed: int | None = None, is_static: bool = False)

RandomScalePerturber applies a Scale transformation from Albumentations.

Attributes:

limit (float | tuple[float, float]):

Range of scaling factors. A single float value is equivalent to a tuple of (-value, value). One will then be added to each value. Therefore, a given value of (-0.2, 0.1) corresponds to scaling the image between 0.8x and 1.1x, and a given value of 0.5 corresponds to scaling the image between 0.5x and 1.5x.

interpolation (int)

OpenCV flag indicating the interpolation algorithm.

probability (float):

Probability of applying the scale transformation.

seed (int | None):

Random seed for reproducibility. None for non-deterministic behavior.

is_static (bool):

If True, resets seed after each call for consistent results.

Methods

from_config	Instantiate a new instance of this class given the configuration JSON-compliant dictionary encapsulating initialization arguments.
get_config	Returns the current configuration of the RandomScalePerturber instance.
get_default_config	Generate and return a default configuration dictionary for this class.
get_impls	Discover plugins, skipping any entrypoints that fail to load.
get_type_string	Returns the fully qualified type string of the PerturbImage class or its subclass.
is_usable	Check whether this class is available for use.
perturb	Apply a BasicTransform from Albumentations to an image.

__init__(*, limit: float | tuple[float, float] = 0.0, interpolation: int = 1, probability: float = 1.0, seed: int | None = None, is_static: bool = False) → None

RandomScalePerturber applies a random scale perturbation to an input image.

It ensures that bounding boxes are adjusted correctly to reflect the translated image coordinates.

Args:

limit:

Range of scaling factors. A single float value is equivalent to a tuple of (-value, value). One will then be added to each value. Therefore, a given value of (-0.2, 0.1) corresponds to scaling the image between 0.8x and 1.1x, and a given value of 0.5 corresponds to scaling the image between 0.5x and 1.5x.

interpolation:

OpenCV flag indicating the interpolation algorithm.

probability:

Probability of applying the scale transformation.

seed:

Random seed for reproducible results. Defaults to None for non-deterministic behavior.

is_static:

If True and seed is provided, resets seed after each perturb call for consistent results across multiple calls (useful for video frame processing).

get_config() → dict[str, Any]

Returns the current configuration of the RandomScalePerturber instance.