Class PoisonedDatasetFolder

core/attacks/Refool.py:238–319

        return img

class PoisonedDatasetFolder(DatasetFolder, AddDatasetFolderTriggerMixin):
    def __init__(self, benign_dataset, y_target, poisoned_rate, poisoned_transform_index, poisoned_target_transform_index, reflection_cadidates,\
            max_image_size=560, ghost_rate=0.49, alpha_b=-1., offset=(0, 0), sigma=-1, ghost_alpha=-1.):
        """
        Args:
            reflection_cadidates (List of numpy.ndarray of shape (H, W, C) or (H, W))
            max_image_size (int): max(Height, Weight) of returned image
            ghost_rate (float): rate of ghost reflection
            alpha_b (float): the ratio of background image in blended image, alpha_b should be in $(0,1)$, set to -1 if random alpha_b is desired
            offset (tuple of 2 interger): the offset of ghost reflection in the direction of x axis and y axis, set to (0,0) if random offset is desired
            sigma (interger): the sigma of gaussian kernel, set to -1 if random sigma is desired
            ghost_alpha (interger): ghost_alpha should be in $(0,1)$, set to -1 if random ghost_alpha is desired
        """
        super(PoisonedDatasetFolder, self).__init__(
            benign_dataset.root,
            benign_dataset.loader,
            benign_dataset.extensions,
            benign_dataset.transform,
            benign_dataset.target_transform,
            None)
        total_num = len(benign_dataset)
        poisoned_num = int(total_num * poisoned_rate)
        assert poisoned_num >= 0, 'poisoned_num should greater than or equal to zero.'
        tmp_list = list(range(total_num))
        random.shuffle(tmp_list)
        self.poisoned_set = frozenset(tmp_list[:poisoned_num])
        
        # Add trigger to images
        if self.transform is None:
            self.poisoned_transform = Compose([])
        else:
            self.poisoned_transform = copy.deepcopy(self.transform)

        # split transform into two pharses
        if poisoned_transform_index < 0:
            poisoned_transform_index = len(self.poisoned_transform.transforms) + poisoned_transform_index
        self.pre_poisoned_transform = Compose(self.poisoned_transform.transforms[:poisoned_transform_index])
        self.post_poisoned_transform = Compose(self.poisoned_transform.transforms[poisoned_transform_index:])

        # Modify labels
        if self.target_transform is None:
            self.poisoned_target_transform = Compose([])
        else:
            self.poisoned_target_transform = copy.deepcopy(self.target_transform)
        self.poisoned_target_transform.transforms.insert(poisoned_target_transform_index, ModifyTarget(y_target))
        
        # Add Trigger
        AddDatasetFolderTriggerMixin.__init__(
            self, 
            total_num, 
            reflection_cadidates, 
            max_image_size, 
            ghost_rate,
            alpha_b,
            offset,
            sigma,
            ghost_alpha)