          """Construct the network. """
          raise NotImplementedError('Must be implemented by the subclass.')
  
      @staticmethod
      def load(model_path, session, ignore_missing=False):
          """Load network weights.
          model_path: The path to the numpy-serialized network weights
          session: The current TensorFlow session
          ignore_missing: If true, serialized weights for missing layers are
                          ignored.
          """
          # pylint: disable=no-member
          data_dict = np.load(model_path, encoding='latin1').item()
  
          for op_name in data_dict:
 
</s> remove         # pylint: disable=no-member
        data_dict = np.load(model_path, encoding='latin1').item()

        for op_name in data_dict:
            with tf.variable_scope(op_name, reuse=True):
                for param_name, data in iteritems(data_dict[op_name]):
                    try:
                        var = tf.get_variable(param_name)
                        session.run(var.assign(data))
                    except ValueError:
                        if not ignore_missing:
                            raise

    def feed(self, *args):
        """Set the input(s) for the next operation by replacing the terminal nodes.
        The arguments can be either layer names or the actual layers.
 </s> add         minsize: minimum faces' size
        threshold: threshold=[th1, th2, th3], th1-3 are three steps's threshold
        factor: the factor used to create a scaling pyramid of face sizes to
                detect in the image.
        pnet, rnet, onet: caffemodel </s> remove     def layer_decorated(self, *args, **kwargs):
        # Automatically set a name if not provided.
        name = kwargs.setdefault('name', self.get_unique_name(operator.__name__))
        # Figure out the layer inputs.
        if len(self.terminals) == 0:  # pylint: disable=len-as-condition
            raise RuntimeError('No input variables found for layer %s.' % name)
        elif len(self.terminals) == 1:
            layer_input = self.terminals[0]
        else:
            layer_input = list(self.terminals)
        # Perform the operation and get the output.
        layer_output = operator(self, layer_input, *args, **kwargs)
        # Add to layer LUT.
        self.layers[name] = layer_output
        # This output is now the input for the next layer.
        self.feed(layer_output)
        # Return self for chained calls.
        return self

    return layer_decorated


class Network():
    """ Tensorflow Network """
    def __init__(self, inputs, trainable=True):
        # The input nodes for this network
        self.inputs = inputs
        # The current list of terminal nodes
        self.terminals = []
        # Mapping from layer names to layers
        self.layers = dict(inputs)
        # If true, the resulting variables are set as trainable
        self.trainable = trainable

        self.setup()

    def setup(self):
        """Construct the network. """
        raise NotImplementedError('Must be implemented by the subclass.')
 </s> add     @staticmethod
    def model_definition():
        """ Keras PNetwork for MTCNN """
        input_ = Input(shape=(None, None, 3))
        var_x = Conv2D(10, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='PReLU1')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(16, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='PReLU2')(var_x)
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='PReLU3')(var_x)
        classifier = Conv2D(2, (1, 1), activation='softmax', name='conv4-1')(var_x)
        bbox_regress = Conv2D(4, (1, 1), name='conv4-2')(var_x)
        return [input_], [classifier, bbox_regress]


class RNet(KSession):
    """ Keras RNet model for MTCNN """
    def __init__(self, model_path):
        super().__init__("MTCNN-RNet", model_path)
        self.define_model(self.model_definition)
        self.load_model_weights()

    @staticmethod
    def model_definition():
        """ Keras RNetwork for MTCNN """
        input_ = Input(shape=(24, 24, 3))
        var_x = Conv2D(28, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)

        var_x = Conv2D(48, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)

        var_x = Conv2D(64, (2, 2), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(128, name='conv4')(var_x)
        var_x = PReLU(name='prelu4')(var_x)
        classifier = Dense(2, activation='softmax', name='conv5-1')(var_x)
        bbox_regress = Dense(4, name='conv5-2')(var_x)
        return [input_], [classifier, bbox_regress]


class ONet(KSession):
    """ Keras ONet model for MTCNN """
    def __init__(self, model_path):
        super().__init__("MTCNN-ONet", model_path)
        self.define_model(self.model_definition)
        self.load_model_weights() </s> remove         assert len(args) != 0  # pylint: disable=len-as-condition
        self.terminals = []
        for fed_layer in args:
            if isinstance(fed_layer, string_types):
                try:
                    fed_layer = self.layers[fed_layer]
                except KeyError:
                    raise KeyError('Unknown layer name fed: %s' % fed_layer)
            self.terminals.append(fed_layer)
        return self

    def get_output(self):
        """Returns the current network output."""
        return self.terminals[-1]

    def get_unique_name(self, prefix):
        """Returns an index-suffixed unique name for the given prefix.
        This is used for auto-generating layer names based on the type-prefix.
 </s> add         logger.debug("Initializing: %s: (model_path: '%s')",
                     self.__class__.__name__, model_path)
        self.minsize = minsize
        self.threshold = threshold
        self.factor = factor

        self.pnet = PNet(model_path[0])
        self.rnet = RNet(model_path[1])
        self.onet = ONet(model_path[2])
        logger.debug("Initialized: %s", self.__class__.__name__)

    def detect_faces(self, batch):
        """Detects faces in an image, and returns bounding boxes and points for them.
        batch: input batch </s> remove     def load_graph(self):
        """ Load the tensorflow Model and weights """
        # pylint: disable=not-context-manager
        logger.verbose("Initializing S3FD Network model...")
        with self.tf.gfile.GFile(self.model_path, "rb") as gfile:
            graph_def = self.tf.GraphDef()
            graph_def.ParseFromString(gfile.read())
        fa_graph = self.tf.Graph()
        with fa_graph.as_default():
            self.tf.import_graph_def(graph_def, name="s3fd")
        return fa_graph

    def get_outputs(self):
        """ Return the output tensors """
        tensor_names = ["concat_31", "transpose_72", "transpose_75", "transpose_78",
                        "transpose_81", "transpose_84", "transpose_87", "transpose_90",
                        "transpose_93", "transpose_96", "transpose_99", "transpose_102"]
        logger.debug("tensor_names: %s", tensor_names)
        tensors = [self.graph.get_tensor_by_name("s3fd/{}:0".format(t_name))
                   for t_name in tensor_names]
        logger.debug("tensors: %s", tensors)
        return tensors

    def set_session(self, target_size, vram_ratio, card_id):
        """ Set the TF Session and initialize """
        # pylint: disable=not-context-manager, no-member
        placeholder = np.zeros((1, 3, target_size[0], target_size[1]))
        config = self.tf.ConfigProto()
        if card_id != -1:
            config.gpu_options.visible_device_list = str(card_id)
        if vram_ratio != 1.0:
            config.gpu_options.per_process_gpu_memory_fraction = vram_ratio

        with self.graph.as_default():
            session = self.tf.Session(config=config)
            self.is_gpu = any("gpu" in str(device).lower() for device in session.list_devices())
            session.run(self.output, feed_dict={self.input: placeholder})
        return session

    def detect_face(self, feed_item):
        """ Detect faces """
        feed_item = feed_item - np.array([104.0, 117.0, 123.0])
        feed_item = feed_item.transpose(2, 0, 1)
        feed_item = feed_item.reshape((1,) + feed_item.shape).astype('float32')
        bboxlist = self.session.run(self.output, feed_dict={self.input: feed_item})
        bboxlist = self.post_process(bboxlist)

        keep = self.nms(bboxlist, 0.3)
        bboxlist = bboxlist[keep, :]
        bboxlist = [x for x in bboxlist if x[-1] >= self.confidence]
 </s> add     @staticmethod
    def prepare_batch(batch):
        """ Prepare a batch for prediction """
        batch = batch - np.array([104.0, 117.0, 123.0])
        batch = batch.transpose(0, 3, 1, 2)
        return batch </s> remove         datatype:  [required] A python type class. This limits the type of data that can be
                   provided in the .ini file and ensures that the value is returned in the
                   correct type to faceswap. Valid datatypes are: <class 'int'>, <class 'float'>,
                   <class 'str'>, <class 'bool'>.
        default:   [required] The default value for this option.
        info:      [required] A string describing what this option does.
        choices:   [optional] If this option's datatype is of <class 'str'> then valid
                   selections can be defined here. This validates the option and also enables
                   a combobox / radio option in the GUI.
        gui_radio: [optional] If <choices> are defined, this indicates that the GUI should use
                   radio buttons rather than a combobox to display this option.
        min_max:   [partial] For <class 'int'> and <class 'float'> datatypes this is required
                   otherwise it is ignored. Should be a tuple of min and max accepted values.
                   This is used for controlling the GUI slider range. Values are not enforced.
        rounding:  [partial] For <class 'int'> and <class 'float'> datatypes this is
                   required otherwise it is ignored. Used for the GUI slider. For floats, this
                   is the number of decimal places to display. For ints this is the step size.
        fixed:     [optional] [train only]. Training configurations are fixed when the model is
                   created, and then reloaded from the state file. Marking an item as fixed=False
                   indicates that this value can be changed for existing models, and will override
                   the value saved in the state file with the updated value in config. If not
                   provided this will default to True.
 </s> add     datatype:  [required] A python type class. This limits the type of data that can be
                provided in the .ini file and ensures that the value is returned in the
                correct type to faceswap. Valid datatypes are: <class 'int'>, <class 'float'>,
                <class 'str'>, <class 'bool'>.
    default:   [required] The default value for this option.
    info:      [required] A string describing what this option does.
    group:     [optional]. A group for grouping options together in the GUI. If not
                provided this will not group this option with any others.
    choices:   [optional] If this option's datatype is of <class 'str'> then valid
                selections can be defined here. This validates the option and also enables
                a combobox / radio option in the GUI.
    gui_radio: [optional] If <choices> are defined, this indicates that the GUI should use
                radio buttons rather than a combobox to display this option.
    min_max:   [partial] For <class 'int'> and <class 'float'> datatypes this is required
                otherwise it is ignored. Should be a tuple of min and max accepted values.
                This is used for controlling the GUI slider range. Values are not enforced.
    rounding:  [partial] For <class 'int'> and <class 'float'> datatypes this is
                required otherwise it is ignored. Used for the GUI slider. For floats, this
                is the number of decimal places to display. For ints this is the step size.
    fixed:     [optional] [train only]. Training configurations are fixed when the model is
                created, and then reloaded from the state file. Marking an item as fixed=False
                indicates that this value can be changed for existing models, and will override
                the value saved in the state file with the updated value in config. If not
                provided this will default to True.
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
          """Construct the network. """
          raise NotImplementedError('Must be implemented by the subclass.')
  
      @staticmethod
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
    def model_definition():
        """ Keras ONetwork for MTCNN """
        input_ = Input(shape=(48, 48, 3))
        var_x = Conv2D(32, (3, 3), strides=1, padding='valid', name='conv1')(input_)
        var_x = PReLU(shared_axes=[1, 2], name='prelu1')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2, padding='same')(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv2')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu2')(var_x)
        var_x = MaxPool2D(pool_size=3, strides=2)(var_x)
        var_x = Conv2D(64, (3, 3), strides=1, padding='valid', name='conv3')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu3')(var_x)
        var_x = MaxPool2D(pool_size=2)(var_x)
        var_x = Conv2D(128, (2, 2), strides=1, padding='valid', name='conv4')(var_x)
        var_x = PReLU(shared_axes=[1, 2], name='prelu4')(var_x)
        var_x = Permute((3, 2, 1))(var_x)
        var_x = Flatten()(var_x)
        var_x = Dense(256, name='conv5')(var_x)
        var_x = PReLU(name='prelu5')(var_x)

        classifier = Dense(2, activation='softmax', name='conv6-1')(var_x)
        bbox_regress = Dense(4, name='conv6-2')(var_x)
        landmark_regress = Dense(10, name='conv6-3')(var_x)
        return [input_], [classifier, bbox_regress, landmark_regress]


class MTCNN():
    """ MTCNN Detector for face alignment """
    # TODO Batching

    def __init__(self, model_path, minsize, threshold, factor):
          """
          # pylint: disable=no-member
          data_dict = np.load(model_path, encoding='latin1').item()
  
          for op_name in data_dict:
keep keep keep keep replace replace replace replace replace replace keep keep keep keep keep
 De-Multiprocess Extract (#871)

* requirements.txt: - Pin opencv to 4.1.1 (fixes cv2-dnn error)

* lib.face_detect.DetectedFace: change LandmarksXY to landmarks_xy. Add left, right, top, bottom attributes

* lib.model.session: Session manager for loading models into different graphs (for Nvidia + CPU)

* plugins.extract._base: New parent class for all extract plugins

* plugins.extract.pipeline. Remove MultiProcessing. Dynamically limit batchsize for Nvidia cards. Remove loglevel input

* S3FD + FAN plugins. Standardise to Keras version for all backends

* Standardize all extract plugins to new threaded codebase

* Documentation. Start implementing Numpy style docstrings for Sphinx Documentation

* Remove s3fd_amd. Change convert OTF to expect DetectedFace object

* faces_detect - clean up and documentation

* Remove PoolProcess

* Migrate manual tool to new extract workflow

* Remove AMD specific extractor code from cli and plugins

* Sort tool to new extract workflow

* Remove multiprocessing from project

* Remove multiprocessing queues from QueueManager

* Remove multiprocessing support from logger

* Move face_filter to new extraction pipeline

* Alignments landmarksXY > landmarks_xy and legacy handling

* Intercept get_backend for sphinx doc build

# Add Sphinx documentation 
plugins/extract/detect/mtcnn.py