Class RandomCrop

mogen/datasets/pipelines/transforms.py:52–101

r"""Random crop motion sequences. Each sequence will be padded with zeros to the maximum length. Args: min_size (int or None): The minimum size of the cropped motion sequence (inclusive). max_size (int or None): The maximum size of the cropped motion

@PIPELINES.register_module()
class RandomCrop(object):
    r"""Random crop motion sequences. Each sequence will be padded with zeros
    to the maximum length.

    Args:
        min_size (int or None): The minimum size of the cropped motion
            sequence (inclusive).
        max_size (int or None): The maximum size of the cropped motion
            sequence (inclusive).
    """

    def __init__(self,
                 min_size: Optional[Union[int, None]] = None,
                 max_size: Optional[Union[int, None]] = None):
        self.min_size = min_size
        self.max_size = max_size
        assert self.min_size is not None
        assert self.max_size is not None

    def __call__(self, results):
        motion = results['motion']
        length = len(motion)
        crop_size = random.randint(self.min_size, self.max_size)
        if length > crop_size:
            idx = random.randint(0, length - crop_size)
            motion = motion[idx:idx + crop_size]
            results['motion_length'] = crop_size
        else:
            results['motion_length'] = length
        padding_length = self.max_size - min(crop_size, length)
        if padding_length > 0:
            D = motion.shape[1:]
            padding_zeros = np.zeros((padding_length, *D), dtype=np.float32)
            motion = np.concatenate([motion, padding_zeros], axis=0)
        results['motion'] = motion
        results['motion_shape'] = motion.shape
        if length >= self.max_size and crop_size == self.max_size:
            results['motion_mask'] = torch.ones(self.max_size).numpy()
        else:
            results['motion_mask'] = torch.cat(
                (torch.ones(min(length, crop_size)),
                 torch.zeros(self.max_size - min(length, crop_size))),
                dim=0).numpy()
        assert len(motion) == self.max_size
        return results

    def __repr__(self):
        repr_str = self.__class__.__name__ + f'(min_size={self.min_size}'
        repr_str += f', max_size={self.max_size})'
        return repr_str


@PIPELINES.register_module()