model/crop.py

def centre_crop(x, target):
    '''
    Center-crop 3-dim. input tensor along last axis so it fits the target tensor shape
    :param x: Input tensor
    :param target: Shape of this tensor will be used as target shape
    :return: Cropped input tensor
    '''
    if x is None:
        return None
    if target is None:
        return x

    target_shape = target.shape
    diff = x.shape[-1] - target_shape[-1]
    assert (diff % 2 == 0)
    crop = diff // 2

    if crop == 0:
        return x
    if crop < 0:
        raise ArithmeticError

    return x[:, :, crop:-crop].contiguous()