mp.tasks.vision.ObjectDetector

    Class that performs object detection on images.

      mp 
 . 
 tasks 
 . 
 vision 
 . 
 ObjectDetector 
 ( 
 graph_config 
 : 
   mp 
 . 
 calculators 
 . 
 core 
 . 
 constant_side_packet_calculator_pb2 
 . 
 mediapipe_dot_framework_dot_calculator__pb2 
 . 
 CalculatorGraphConfig 
 
 
 , 
 running_mode 
 : 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 RunningMode 
 
 
 , 
 packet_callback 
 : 
 Optional 
 [ 
 Callable 
 [[ 
 Mapping 
 [ 
 str 
 , 
 packet_module 
 . 
 Packet 
 ]], 
 None 
 ]] 
 = 
 None 
 ) 
 -> 
 None

    The API expects a TFLite model with mandatory TFLite Model Metadata.

    (kTfLiteUInt8/kTfLiteFloat32)
    • image input of size [batch x height x width x channels] .
    • batch inference is not supported ( batch is required to be 1).
    • only RGB inputs are supported ( channels is required to be 3).
    • if type is kTfLiteFloat32, NormalizationOptions are required to be attached to the metadata for input normalization.

    Output tensors must be the 4 outputs of a DetectionPostProcess op, i.e: (kTfLiteFloat32)

    • locations tensor of size [num_results x 4] , the inner array representing bounding boxes in the form [top, left, right, bottom].
    • BoundingBoxProperties are required to be attached to the metadata and must specify type=BOUNDARIES and coordinate_type=RATIO. (kTfLiteFloat32)
    • classes tensor of size [num_results] , each value representing the integer index of a class.
    • optional (but recommended) label map(s) can be attached as AssociatedFile-s with type TENSOR_VALUE_LABELS, containing one label per line. The first such AssociatedFile (if any) is used to fill the class_name field of the results. The display_name field is filled from the AssociatedFile (if any) whose locale matches the display_names_locale field of the ObjectDetectorOptions used at creation time ("en" by default, i.e. English). If none of these are available, only the index field of the results will be filled. (kTfLiteFloat32)
    • scores tensor of size [num_results] , each value representing the score of the detected object.
    • optional score calibration can be attached using ScoreCalibrationOptions and an AssociatedFile with type TENSOR_AXIS_SCORE_CALIBRATION. See metadata_schema.fbs 1 for more details. (kTfLiteFloat32)
    • integer num_results as a tensor of size [1]

    An example of such model can be found at: https://tfhub.dev/google/lite-model/object_detection/mobile_object_localizer_v1/1/metadata/1

    graph_config
    The mediapipe vision task graph config proto.
    running_mode
    The running mode of the mediapipe vision task.
    packet_callback
    The optional packet callback for getting results asynchronously in the live stream mode.

    ValueError
    The packet callback is not properly set based on the task's running mode.

    Methods

    close

    View source 

      close 
 () 
 -> 
 None

    Shuts down the mediapipe vision task instance.

    Raises

    RuntimeError
    If the mediapipe vision task failed to close.

    convert_to_normalized_rect

    View source 

      convert_to_normalized_rect 
 ( 
 options 
 : 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 holistic_landmarker 
 . 
 image_processing_options_module 
 . 
 ImageProcessingOptions 
 
 
 , 
 image 
 : 
   mp 
 . 
 Image 
 
 
 , 
 roi_allowed 
 : 
 bool 
 = 
 True 
 ) 
 -> 
   mp 
 . 
 tasks 
 . 
 components 
 . 
 containers 
 . 
 NormalizedRect

    Converts from ImageProcessingOptions to NormalizedRect, performing sanity checks on-the-fly.

    If the input ImageProcessingOptions is not present, returns a default NormalizedRect covering the whole image with rotation set to 0. If 'roi_allowed' is false, an error will be returned if the input ImageProcessingOptions has its 'region_of_interest' field set.

    Args

    options
    Options for image processing.
    image
    The image to process.
    roi_allowed
    Indicates if the region_of_interest field is allowed to be set. By default, it's set to True.

    Returns
    A normalized rect proto that represents the image processing options.

    create_from_model_path

    View source 

      @classmethod 
 
  create_from_model_path 
 ( 
 model_path 
 : 
 str 
 ) 
 -> 
 'ObjectDetector'

    Creates an ObjectDetector object from a TensorFlow Lite model and the default ObjectDetectorOptions .

    Note that the created ObjectDetector instance is in image mode, for detecting objects on single image inputs.

    Args

    model_path
    Path to the model.

    Returns
    ObjectDetector object that's created from the model file and the default ObjectDetectorOptions .

    Raises

    ValueError
    If failed to create ObjectDetector object from the provided file such as invalid file path.
    RuntimeError
    If other types of error occurred.

    create_from_options

    View source 

      @classmethod 
 
  create_from_options 
 ( 
 options 
 : 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 ObjectDetectorOptions 
 
 
 ) 
 -> 
 'ObjectDetector'

    Creates the ObjectDetector object from object detector options.

    Args

    options
    Options for the object detector task.

    Returns
    ObjectDetector object that's created from options .

    Raises

    ValueError
    If failed to create ObjectDetector object from ObjectDetectorOptions such as missing the model.
    RuntimeError
    If other types of error occurred.

    detect

    View source 

      detect 
 ( 
 image 
 : 
   mp 
 . 
 Image 
 
 
 , 
 image_processing_options 
 : 
 Optional 
 [ 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 holistic_landmarker 
 . 
 image_processing_options_module 
 . 
 ImageProcessingOptions 
 
 
 ] 
 = 
 None 
 ) 
 -> 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 FaceDetectorResult

    Performs object detection on the provided MediaPipe Image.

    Only use this method when the ObjectDetector is created with the image running mode.

    Args

    image
    MediaPipe Image.
    image_processing_options
    Options for image processing.

    Returns
    A detection result object that contains a list of detections, each detection has a bounding box that is expressed in the unrotated input frame of reference coordinates system, i.e. in [0,image_width) x [0, image_height) , which are the dimensions of the underlying image data.

    Raises

    ValueError
    If any of the input arguments is invalid.
    RuntimeError
    If object detection failed to run.

    detect_async

    View source 

      detect_async 
 ( 
 image 
 : 
   mp 
 . 
 Image 
 
 
 , 
 timestamp_ms 
 : 
 int 
 , 
 image_processing_options 
 : 
 Optional 
 [ 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 holistic_landmarker 
 . 
 image_processing_options_module 
 . 
 ImageProcessingOptions 
 
 
 ] 
 = 
 None 
 ) 
 -> 
 None

    Sends live image data (an Image with a unique timestamp) to perform object detection.

    Only use this method when the ObjectDetector is created with the live stream running mode. The input timestamps should be monotonically increasing for adjacent calls of this method. This method will return immediately after the input image is accepted. The results will be available via the result_callback provided in the ObjectDetectorOptions . The detect_async method is designed to process live stream data such as camera input. To lower the overall latency, object detector may drop the input images if needed. In other words, it's not guaranteed to have output per input image.

    The result_callback prvoides:

    • A detection result object that contains a list of detections, each detection has a bounding box that is expressed in the unrotated input frame of reference coordinates system, i.e. in [0,image_width) x [0, image_height) , which are the dimensions of the underlying image data.
    • The input image that the object detector runs on.
    • The input timestamp in milliseconds.

    Args

    image
    MediaPipe Image.
    timestamp_ms
    The timestamp of the input image in milliseconds.
    image_processing_options
    Options for image processing.

    Raises

    ValueError
    If the current input timestamp is smaller than what the object detector has already processed.

    detect_for_video

    View source 

      detect_for_video 
 ( 
 image 
 : 
   mp 
 . 
 Image 
 
 
 , 
 timestamp_ms 
 : 
 int 
 , 
 image_processing_options 
 : 
 Optional 
 [ 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 holistic_landmarker 
 . 
 image_processing_options_module 
 . 
 ImageProcessingOptions 
 
 
 ] 
 = 
 None 
 ) 
 -> 
   mp 
 . 
 tasks 
 . 
 vision 
 . 
 FaceDetectorResult

    Performs object detection on the provided video frames.

    Only use this method when the ObjectDetector is created with the video running mode. It's required to provide the video frame's timestamp (in milliseconds) along with the video frame. The input timestamps should be monotonically increasing for adjacent calls of this method.

    Args

    image
    MediaPipe Image.
    timestamp_ms
    The timestamp of the input video frame in milliseconds.
    image_processing_options
    Options for image processing.

    Returns
    A detection result object that contains a list of detections, each detection has a bounding box that is expressed in the unrotated input frame of reference coordinates system, i.e. in [0,image_width) x [0, image_height) , which are the dimensions of the underlying image data.

    Raises

    ValueError
    If any of the input arguments is invalid.
    RuntimeError
    If object detection failed to run.

    get_graph_config

    View source 

      get_graph_config 
 () 
 -> 
   mp 
 . 
 calculators 
 . 
 core 
 . 
 constant_side_packet_calculator_pb2 
 . 
 mediapipe_dot_framework_dot_calculator__pb2 
 . 
 CalculatorGraphConfig

    Returns the canonicalized CalculatorGraphConfig of the underlying graph.

    __enter__

    View source 

      __enter__ 
 ()

    Return self upon entering the runtime context.

    __exit__

    View source 

      __exit__ 
 ( 
 unused_exc_type 
 , 
 unused_exc_value 
 , 
 unused_traceback 
 )

    Shuts down the mediapipe vision task instance on exit of the context manager.

    Raises

    RuntimeError
    If the mediapipe vision task failed to close.
    Design a Mobile Site
    View Site in Mobile | Classic
    Share by: