CubicSymmetry

Applies a random cubic symmetry transformation to a 3D volume. This transform is a 3D extension of D4. While D4 handles the 8 symmetries of a square (4 rotations x 2 reflections), CubicSymmetry handles all 48 symmetries of a cube. Like D4, this transform does not create any interpolation artifacts as it only remaps voxels from one position to another without any interpolation. The 48 transformations consist of: - 24 rotations (orientation-preserving): * 4 rotations around each face diagonal (6 face diagonals x 4 rotations = 24) - 24 rotoreflections (orientation-reversing): * Reflection through a plane followed by any of the 24 rotations For a cube, these transformations preserve: - All face centers (6) - All vertex positions (8) - All edge centers (12) works with 3D volumes and masks of the shape (D, H, W) or (D, H, W, C) Args: p (float): Probability of applying the transform. Default: 1.0 Targets: volume, mask3d, keypoints Image types: uint8, float32 Note: - This transform is particularly useful for data augmentation in 3D medical imaging, crystallography, and voxel-based 3D modeling where the object's orientation is arbitrary. - All transformations preserve the object's chirality (handedness) when using pure rotations (indices 0-23) and invert it when using rotoreflections (indices 24-47). Example: >>> 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) >>> transform = A.CubicSymmetry(p=1.0) >>> transformed = transform(volume=volume, mask3d=mask3d) >>> transformed_volume = transformed["volume"] >>> transformed_mask3d = transformed["mask3d"] See Also: - D4: The 2D version that handles the 8 symmetries of a square

Supported Targets

• Volume
• Mask3D
• Keypoints

Parameters

p

Type: floatDefault: 1