CoarseDropout3D

Targets:

keypoints

Image Types:uint8, float32

Randomly drop cuboid regions from a 3D volume (and optionally mask) to simulate occlusion. Hole size/count configurable.

Arguments

num_holes_range

tuple[int, int]

[1,1]

Range (min, max) for the number of cuboid regions to drop out. Default: (1, 1)

hole_depth_range

tuple[float, float]

[0.1,0.2]

Range (min, max) for the depth of dropout regions as a fraction of the volume depth (between 0 and 1). Default: (0.1, 0.2)

hole_height_range

tuple[float, float]

[0.1,0.2]

Range (min, max) for the height of dropout regions as a fraction of the volume height (between 0 and 1). Default: (0.1, 0.2)

hole_width_range

tuple[float, float]

[0.1,0.2]

Range (min, max) for the width of dropout regions as a fraction of the volume width (between 0 and 1). Default: (0.1, 0.2)

fill

tuple[float, ...] | float

Value for the dropped voxels. Can be:

int or float: all channels are filled with this value
tuple: tuple of values for each channel Default: 0

fill_mask

tuple[float, ...] | float | None

Fill value for dropout regions in the 3D mask. If None, mask regions corresponding to volume dropouts are unchanged. Default: None

p

float

0.5

Probability of applying the transform. Default: 0.5

Examples

>>> import numpy as np
>>> import albumentations as A
>>> volume = np.random.randint(0, 256, (10, 100, 100), dtype=np.uint8)  # (D, H, W)
>>> mask3d = np.random.randint(0, 2, (10, 100, 100), dtype=np.uint8)    # (D, H, W)
>>> aug = A.CoarseDropout3D(
...     num_holes_range=(3, 6),
...     hole_depth_range=(0.1, 0.2),
...     hole_height_range=(0.1, 0.2),
...     hole_width_range=(0.1, 0.2),
...     fill=0,
...     p=1.0
... )
>>> transformed = aug(volume=volume, mask3d=mask3d)
>>> transformed_volume, transformed_mask3d = transformed["volume"], transformed["mask3d"]

Notes

The actual number and size of dropout regions are randomly chosen within the specified ranges.
All values in hole_depth_range, hole_height_range and hole_width_range must be between 0 and 1.
If you want to apply dropout only in the XY plane while preserving the full depth dimension, consider using CoarseDropout instead. CoarseDropout will apply the same rectangular dropout to each slice independently, effectively creating cylindrical dropout regions that extend through the entire depth of the volume.

>>> import numpy as np >>> import albumentations as A >>> volume = np.random.randint(0, 256, (10, 100, 100), dtype=np.uint8) # (D, H, W) >>> mask3d = np.random.randint(0, 2, (10, 100, 100), dtype=np.uint8) # (D, H, W) >>> aug = A.CoarseDropout3D( ... num_holes_range=(3, 6), ... hole_depth_range=(0.1, 0.2), ... hole_height_range=(0.1, 0.2), ... hole_width_range=(0.1, 0.2), ... fill=0, ... p=1.0 ... ) >>> transformed = aug(volume=volume, mask3d=mask3d) >>> transformed_volume, transformed_mask3d = transformed["volume"], transformed["mask3d"]