def _rescale_0_1(batch):
    """
    Rescale all image from batch, per channel, between 0 and 1
    """
    for image_id in range(batch.size(0)):
        for channel_id in range(batch[image_id].size(0)):
            pix_min = batch[image_id][channel_id].min()
            pix_range = batch[image_id][channel_id].max() - pix_min
            batch[image_id][channel_id].sub_(pix_min).div_(pix_range)
    return batch