art.estimators.object_detection

Module containing estimators for object detection.

Mixin Base Class Object Detector

class art.estimators.object_detection.ObjectDetectorMixin

Mix-in Base class for ART object detectors.

Object Detector PyTorch Faster-RCNN

class art.estimators.object_detection.PyTorchFasterRCNN(model: Optional[torchvision.models.detection.fasterrcnn_resnet50_fpn] = None, clip_values: Optional[CLIP_VALUES_TYPE] = None, channels_first: Optional[bool] = None, preprocessing_defences: Optional[Union[Preprocessor, List[Preprocessor]]] = None, postprocessing_defences: Optional[Union[Postprocessor, List[Postprocessor]]] = None, preprocessing: PREPROCESSING_TYPE = None, attack_losses: Tuple[str, …] = ('loss_classifier', 'loss_box_reg', 'loss_objectness', 'loss_rpn_box_reg'), device_type: str = 'gpu')

This class implements a model-specific object detector using Faster-RCNN and PyTorch.

__init__(model: Optional[torchvision.models.detection.fasterrcnn_resnet50_fpn] = None, clip_values: Optional[CLIP_VALUES_TYPE] = None, channels_first: Optional[bool] = None, preprocessing_defences: Optional[Union[Preprocessor, List[Preprocessor]]] = None, postprocessing_defences: Optional[Union[Postprocessor, List[Postprocessor]]] = None, preprocessing: PREPROCESSING_TYPE = None, attack_losses: Tuple[str, …] = ('loss_classifier', 'loss_box_reg', 'loss_objectness', 'loss_rpn_box_reg'), device_type: str = 'gpu')

Initialization.

Parameters

  • model –

    Faster-RCNN model. The output of the model is List[Dict[Tensor]], one for each input image. The fields of the Dict are as follows:

    • boxes (FloatTensor[N, 4]): the predicted boxes in [x1, y1, x2, y2] format, with values between 0 and H and 0 and W

    • labels (Int64Tensor[N]): the predicted labels for each image

    • scores (Tensor[N]): the scores or each prediction

  • clip_values – Tuple of the form (min, max) of floats or np.ndarray representing the minimum and maximum values allowed for features. If floats are provided, these will be used as the range of all features. If arrays are provided, each value will be considered the bound for a feature, thus the shape of clip values needs to match the total number of features.

  • channels_first – Set channels first or last.

  • preprocessing_defences – Preprocessing defence(s) to be applied by the classifier.

  • postprocessing_defences – Postprocessing defence(s) to be applied by the classifier.

  • preprocessing – Tuple of the form (subtrahend, divisor) of floats or np.ndarray of values to be used for data preprocessing. The first value will be subtracted from the input. The input will then be divided by the second one.

  • attack_losses (Tuple) – Tuple of any combination of strings of loss components: ‘loss_classifier’, ‘loss_box_reg’, ‘loss_objectness’, and ‘loss_rpn_box_reg’.

  • device_type (str) – Type of device to be used for model and tensors, if cpu run on CPU, if gpu run on GPU if available otherwise run on CPU.

property channels_first
Returns

Boolean to indicate index of the color channels in the sample x.

property clip_values

Return the clip values of the input samples.

Returns

Clip values (min, max).

compute_loss(x: numpy.ndarray, y: numpy.ndarray, **kwargs) → numpy.ndarray

Compute the loss of the neural network for samples x.

Parameters

  • x (ndarray) – Samples of shape (nb_samples, nb_features) or (nb_samples, nb_pixels_1, nb_pixels_2, nb_channels) or (nb_samples, nb_channels, nb_pixels_1, nb_pixels_2).

  • y (ndarray) – Target values (class labels) one-hot-encoded of shape (nb_samples, nb_classes) or indices of shape (nb_samples,).

Returns

Loss values.

Return type

Format as expected by the model

property device

Get current used device.

Returns

Current used device.

property device_type

Return the type of device on which the estimator is run.

Returns

Type of device on which the estimator is run, either gpu or cpu.

fit(x: numpy.ndarray, y, batch_size: int = 128, nb_epochs: int = 20, **kwargs) → None

Fit the model of the estimator on the training data x and y.

Parameters

  • x (ndarray) – Samples of shape (nb_samples, nb_features) or (nb_samples, nb_pixels_1, nb_pixels_2, nb_channels) or (nb_samples, nb_channels, nb_pixels_1, nb_pixels_2).

  • y (Format as expected by the model) – Target values.

  • batch_size (int) – Batch size.

  • nb_epochs (int) – Number of training epochs.

fit_generator(generator: DataGenerator, nb_epochs: int = 20, **kwargs) → None

Fit the estimator using a generator yielding training batches. Implementations can provide framework-specific versions of this function to speed-up computation.

Parameters

  • generator – Batch generator providing (x, y) for each epoch.

  • nb_epochs (int) – Number of training epochs.

get_activations(x: numpy.ndarray, layer: Union[int, str], batch_size: int, framework: bool = False) → numpy.ndarray

Return the output of a specific layer for samples x where layer is the index of the layer between 0 and nb_layers - 1 or the name of the layer. The number of layers can be determined by counting the results returned by calling `layer_names.

Return type

ndarray

Parameters

  • x (ndarray) – Samples

  • layer – Index or name of the layer.

  • batch_size (int) – Batch size.

  • framework (bool) – If true, return the intermediate tensor representation of the activation.

Returns

The output of layer, where the first dimension is the batch size corresponding to x.

get_params() → Dict[str, Any]

Get all parameters and their values of this estimator.

Returns

A dictionary of string parameter names to their value.

property input_shape

Return the shape of one input sample.

Returns

Shape of one input sample.

property layer_names

Return the names of the hidden layers in the model, if applicable.

Returns

The names of the hidden layers in the model, input and output layers are ignored.

Warning

layer_names tries to infer the internal structure of the model. This feature comes with no guarantees on the correctness of the result. The intended order of the layers tries to match their order in the model, but this is not guaranteed either.

loss_gradient(x: numpy.ndarray, y: Union[List[Dict[str, numpy.ndarray]], List[Dict[str, torch.Tensor]]], **kwargs) → numpy.ndarray

Compute the gradient of the loss function w.r.t. x.

Return type

ndarray

Parameters

  • x (ndarray) – Samples of shape (nb_samples, height, width, nb_channels).

  • y –

    Target values of format List[Dict[Tensor]], one for each input image. The fields of the Dict are as follows:

    • boxes (FloatTensor[N, 4]): the predicted boxes in [x1, y1, x2, y2] format, with values between 0 and H and 0 and W

    • labels (Int64Tensor[N]): the predicted labels for each image

    • scores (Tensor[N]): the scores or each prediction.

Returns

Loss gradients of the same shape as x.

property model

Return the model.

Returns

The model.

predict(x: numpy.ndarray, batch_size: int = 128, **kwargs) → List[Dict[str, numpy.ndarray]]

Perform prediction for a batch of inputs.

Return type

List

Parameters

  • x (ndarray) – Samples of shape (nb_samples, height, width, nb_channels).

  • batch_size (int) – Batch size.

Returns

Predictions of format List[Dict[str, np.ndarray]], one for each input image. The fields of the Dict are as follows:

  • boxes [N, 4]: the predicted boxes in [x1, y1, x2, y2] format, with values between 0 and H and 0 and W

  • labels [N]: the predicted labels for each image

  • scores [N]: the scores or each prediction.

set_batchnorm(train: bool) → None

Set all batch normalization layers into train or eval mode.

Parameters

train (bool) – False for evaluation mode.

set_dropout(train: bool) → None

Set all dropout layers into train or eval mode.

Parameters

train (bool) – False for evaluation mode.

set_params(**kwargs) → None

Take a dictionary of parameters and apply checks before setting them as attributes.

Parameters

kwargs – A dictionary of attributes.

Object Detector TensorFlow Faster-RCNN

class art.estimators.object_detection.TensorFlowFasterRCNN(images: tf.Tensor, model: Optional[FasterRCNNMetaArch] = None, filename: Optional[str] = None, url: Optional[str] = None, sess: Optional[Session] = None, is_training: bool = False, clip_values: Optional[CLIP_VALUES_TYPE] = None, channels_first: bool = False, preprocessing_defences: Optional[Union[Preprocessor, List[Preprocessor]]] = None, postprocessing_defences: Optional[Union[Postprocessor, List[Postprocessor]]] = None, preprocessing: PREPROCESSING_TYPE = (0.0, 1.0), attack_losses: Tuple[str, …] = ('Loss/RPNLoss/localization_loss', 'Loss/RPNLoss/objectness_loss', 'Loss/BoxClassifierLoss/localization_loss', 'Loss/BoxClassifierLoss/classification_loss'))

This class implements a model-specific object detector using Faster-RCNN and TensorFlow.

__init__(images: tf.Tensor, model: Optional[FasterRCNNMetaArch] = None, filename: Optional[str] = None, url: Optional[str] = None, sess: Optional[Session] = None, is_training: bool = False, clip_values: Optional[CLIP_VALUES_TYPE] = None, channels_first: bool = False, preprocessing_defences: Optional[Union[Preprocessor, List[Preprocessor]]] = None, postprocessing_defences: Optional[Union[Postprocessor, List[Postprocessor]]] = None, preprocessing: PREPROCESSING_TYPE = (0.0, 1.0), attack_losses: Tuple[str, …] = ('Loss/RPNLoss/localization_loss', 'Loss/RPNLoss/objectness_loss', 'Loss/BoxClassifierLoss/localization_loss', 'Loss/BoxClassifierLoss/classification_loss'))

Initialization of an instance TensorFlowFasterRCNN.

Parameters

  • images – Input samples of shape (nb_samples, height, width, nb_channels).

  • model –

    A TensorFlow Faster-RCNN model. The output that can be computed from the model includes a tuple of (predictions, losses, detections):

    • predictions: a dictionary holding “raw” prediction tensors.

    • losses: a dictionary mapping loss keys (Loss/RPNLoss/localization_loss,

      Loss/RPNLoss/objectness_loss, Loss/BoxClassifierLoss/localization_loss, Loss/BoxClassifierLoss/classification_loss) to scalar tensors representing corresponding loss values.

    • detections: a dictionary containing final detection results.

  • filename – Filename of the detection model without filename extension.

  • url – URL to download archive of detection model including filename extension.

  • sess – Computation session.

  • is_training (bool) – A boolean indicating whether the training version of the computation graph should be constructed.

  • clip_values – Tuple of the form (min, max) of floats or np.ndarray representing the minimum and maximum values allowed for input image features. If floats are provided, these will be used as the range of all features. If arrays are provided, each value will be considered the bound for a feature, thus the shape of clip values needs to match the total number of features.

  • channels_first (bool) – Set channels first or last.

  • preprocessing_defences – Preprocessing defence(s) to be applied by the classifier.

  • postprocessing_defences – Postprocessing defence(s) to be applied by the classifier.

  • preprocessing – Tuple of the form (subtractor, divider) of floats or np.ndarray of values to be used for data preprocessing. The first value will be subtracted from the input. The input will then be divided by the second one.

  • attack_losses (Tuple) – Tuple of any combination of strings of the following loss components: first_stage_localization_loss, first_stage_objectness_loss, second_stage_localization_loss, second_stage_classification_loss.

property channels_first
Returns

Boolean to indicate index of the color channels in the sample x.

property clip_values

Return the clip values of the input samples.

Returns

Clip values (min, max).

compute_loss(x: numpy.ndarray, y: numpy.ndarray, **kwargs) → numpy.ndarray

Compute the loss of the neural network for samples x.

Parameters

  • x (ndarray) – Samples of shape (nb_samples, nb_features) or (nb_samples, nb_pixels_1, nb_pixels_2, nb_channels) or (nb_samples, nb_channels, nb_pixels_1, nb_pixels_2).

  • y (ndarray) – Target values (class labels) one-hot-encoded of shape (nb_samples, nb_classes) or indices of shape (nb_samples,).

Returns

Loss values.

Return type

Format as expected by the model

property detections

Get the _detections attribute.

Returns

A dictionary containing final detection results.

fit(x: numpy.ndarray, y, batch_size: int = 128, nb_epochs: int = 20, **kwargs) → None

Fit the model of the estimator on the training data x and y.

Parameters

  • x (ndarray) – Samples of shape (nb_samples, nb_features) or (nb_samples, nb_pixels_1, nb_pixels_2, nb_channels) or (nb_samples, nb_channels, nb_pixels_1, nb_pixels_2).

  • y (Format as expected by the model) – Target values.

  • batch_size (int) – Batch size.

  • nb_epochs (int) – Number of training epochs.

fit_generator(generator: DataGenerator, nb_epochs: int = 20, **kwargs) → None

Fit the estimator using a generator yielding training batches. Implementations can provide framework-specific versions of this function to speed-up computation.

Parameters

  • generator – Batch generator providing (x, y) for each epoch.

  • nb_epochs (int) – Number of training epochs.

get_activations(x: numpy.ndarray, layer: Union[int, str], batch_size: int, framework: bool = False) → numpy.ndarray

Return the output of a specific layer for samples x where layer is the index of the layer between 0 and nb_layers - 1 or the name of the layer. The number of layers can be determined by counting the results returned by calling `layer_names.

Return type

ndarray

Parameters

  • x (ndarray) – Samples

  • layer – Index or name of the layer.

  • batch_size (int) – Batch size.

  • framework (bool) – If true, return the intermediate tensor representation of the activation.

Returns

The output of layer, where the first dimension is the batch size corresponding to x.

get_params() → Dict[str, Any]

Get all parameters and their values of this estimator.

Returns

A dictionary of string parameter names to their value.

property input_images

Get the images attribute.

Returns

The input image tensor.

property input_shape

Return the shape of one input sample.

Returns

Shape of one input sample.

property layer_names

Return the names of the hidden layers in the model, if applicable.

Returns

The names of the hidden layers in the model, input and output layers are ignored.

Warning

layer_names tries to infer the internal structure of the model. This feature comes with no guarantees on the correctness of the result. The intended order of the layers tries to match their order in the model, but this is not guaranteed either.

loss_gradient(x: numpy.ndarray, y: List[Dict[str, numpy.ndarray]], **kwargs) → numpy.ndarray

Compute the gradient of the loss function w.r.t. x.

Return type

ndarray

Parameters

  • x (ndarray) – Samples of shape (nb_samples, height, width, nb_channels).

  • y (List) –

    A dictionary of target values. The fields of the dictionary are as follows:

    • boxes: A list of nb_samples size of 2-D tf.float32 tensors of shape [num_boxes, 4] containing coordinates of the groundtruth boxes. Groundtruth boxes are provided in [y_min, x_min, y_max, x_max] format and also assumed to be normalized as well as clipped relative to the image window with conditions y_min <= y_max and x_min <= x_max.

    • labels: A list of nb_samples size of 1-D tf.float32 tensors of shape [num_boxes] containing the class targets with the zero index assumed to map to the first non-background class.

    • scores: A list of nb_samples size of 1-D tf.float32 tensors of shape [num_boxes] containing weights for groundtruth boxes.

Returns

Loss gradients of the same shape as x.

property losses

Get the _losses attribute.

Returns

A dictionary mapping loss keys (Loss/RPNLoss/localization_loss, Loss/RPNLoss/objectness_loss, Loss/BoxClassifierLoss/localization_loss, Loss/BoxClassifierLoss/classification_loss) to scalar tensors representing corresponding loss values.

property model

Return the model.

Returns

The model.

predict(x: numpy.ndarray, batch_size: int = 128, standardise_output: bool = False, **kwargs) → List[Dict[str, numpy.ndarray]]

Perform prediction for a batch of inputs.

Return type

List

Parameters

  • x (ndarray) – Samples of shape (nb_samples, height, width, nb_channels).

  • batch_size (int) – Batch size.

  • standardise_output (bool) – True if output should be standardised. Box coordinates will be normalised to [0, 1] and label index will be decreased by 1 to adhere to COCO categories.

Returns

A dictionary containing the following fields:

Returns

Predictions of format List[Dict[str, np.ndarray]], one for each input image. The fields of the Dict are as follows:

  • boxes [N, 4]: the predicted boxes in [x1, y1, x2, y2] format, with values between 0 and H and 0 and W

  • labels [N]: the predicted labels for each image

  • scores [N]: the scores or each prediction.

property predictions

Get the _predictions attribute.

Returns

A dictionary holding “raw” prediction tensors.

property sess

Get current TensorFlow session.

Returns

The current TensorFlow session.

set_params(**kwargs) → None

Take a dictionary of parameters and apply checks before setting them as attributes.

Parameters

kwargs – A dictionary of attributes.