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| import numpy as np |
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| class Permutation(object): |
| """ |
| Defines a fixed permutation for a numpy array. |
| """ |
| def __init__(self) -> None: |
| """ |
| Initializes the permutation. |
| """ |
| self.perm = None |
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| def __call__(self, sample: np.ndarray) -> np.ndarray: |
| """ |
| Randomly defines the permutation and applies the transformation. |
| :param sample: image to be permuted |
| :return: permuted image |
| """ |
| old_shape = sample.shape |
| if self.perm is None: |
| self.perm = np.random.permutation(len(sample.flatten())) |
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| return sample.flatten()[self.perm].reshape(old_shape) |
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|
| class FixedPermutation(object): |
| """ |
| Defines a fixed permutation (given the seed) for a numpy array. |
| """ |
| def __init__(self, seed: int) -> None: |
| """ |
| Defines the seed. |
| :param seed: seed of the permutation |
| """ |
| self.perm = None |
| self.seed = seed |
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| def __call__(self, sample: np.ndarray) -> np.ndarray: |
| """ |
| Defines the permutation and applies the transformation. |
| :param sample: image to be permuted |
| :return: permuted image |
| """ |
| old_shape = sample.shape |
| if self.perm is None: |
| np.random.seed(self.seed) |
| self.perm = np.random.permutation(len(sample.flatten())) |
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| return sample.flatten()[self.perm].reshape(old_shape) |
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