Skip to content

Postprocessor Module

degirum.postprocessor.ClassificationResults

Bases: InferenceResults

InferenceResult class implementation for classification results type

degirum.postprocessor.ClassificationResults.image_overlay property

Image with AI inference results drawn. Image type is defined by the selected graphical backend. Each time this property is accessed, new overlay image object is created and all overlay details are redrawn according to the current settings of overlay_*** properties.

degirum.postprocessor.ClassificationResults.overlay_show_labels_below property writable

Specifies if overlay labels should be drawn below the image or on image itself

degirum.postprocessor.ClassificationResults.__str__()

Convert inference results to string

degirum.postprocessor.DetectionResults

Bases: InferenceResults

InferenceResult class implementation for detection results type

degirum.postprocessor.DetectionResults.image_overlay property

Image with AI inference results drawn. Image type is defined by the selected graphical backend.

degirum.postprocessor.DetectionResults.__str__()

Convert inference results to string

degirum.postprocessor.Hand_DetectionResults

Bases: InferenceResults

InferenceResult class implementation for pose detection results type

degirum.postprocessor.Hand_DetectionResults.image_overlay property

Image with AI inference results drawn. Image type is defined by the selected graphical backend.

degirum.postprocessor.Hand_DetectionResults.__str__()

Convert inference results to string

degirum.postprocessor.InferenceResults

Inference results container class.

This class is a base class for a set of classes designed to handle inference results of particular model types such as classification, detection etc.

Note

You never construct model objects yourself. Objects of those classes are returned by various predict methods of degirum.model.Model class.

degirum.postprocessor.InferenceResults.image property

Original image.

Returned image object type is defined by the selected graphical backend (see degirum.model.Model.image_backend).

degirum.postprocessor.InferenceResults.image_model property

Model input image data: image converted to AI model input specifications.

Image type is raw binary array.

degirum.postprocessor.InferenceResults.image_overlay property

Image with AI inference results drawn on a top of original image.

Drawing details depend on the inference result type:

  • For classification models the list of class labels with probabilities is printed below the original image.
  • For object detection models bounding boxes of detected object are drawn on the original image.
  • For pose detection models detected keypoints and keypoint connections are drawn on the original image.
  • For segmentation models detected segments are drawn on the original image.

Returned image object type is defined by the selected graphical backend (see degirum.model.Model.image_backend).

degirum.postprocessor.InferenceResults.info property

Input data frame information object.

degirum.postprocessor.InferenceResults.overlay_alpha: float property writable

Alpha-blend weight for overlay details.

degirum.postprocessor.InferenceResults.overlay_color property writable

Color for inference results drawing on overlay image.

3-element RGB tuple or list of 3-element RGB tuples.

degirum.postprocessor.InferenceResults.overlay_fill_color: tuple property writable

Image fill color in case of image padding.

3-element RGB tuple.

degirum.postprocessor.InferenceResults.overlay_font_scale: float property writable

Font scale to use for overlay text.

degirum.postprocessor.InferenceResults.overlay_line_width: int property writable

Line width in pixels for inference results drawing on overlay image.

degirum.postprocessor.InferenceResults.overlay_show_labels: bool property writable

Specifies if class labels should be drawn on overlay image.

degirum.postprocessor.InferenceResults.overlay_show_probabilities: bool property writable

Specifies if class probabilities should be drawn on overlay image.

degirum.postprocessor.InferenceResults.results: list property

Inference results list.

Each element of the list is a dictionary containing information about one inference result. The dictionary contents depends on the AI model.

For classification models each inference result dictionary contains the following keys:

  • category_id: class numeric ID.
  • label: class label string.
  • score: class probability.

Example:

[
    {'category_id': 0, 'label': 'cat', 'score': 0.99},
    {'category_id': 1, 'label': 'dog', 'score': 0.01}
]

For multi-label classification models each inference result dictionary contains the following keys:

  • classifier: object class string.
  • results: list of class labels and its scores. Scores are optional.

The results list element is a dictionary with the following keys:

  • label: class label string.
  • score: optional class label probability.

Example:

[
    {
        'classifier': 'vehicle color',
        'results': [
                                {'label': 'red', 'score': 0.99},
                                {'label': 'blue', 'score': 0.01}
                        ]
    },
    {
        'classifier': 'vehicle type',
        'results': [
                                {'label': 'car', 'score': 0.99},
            {'label': 'truck', 'score': 0.01}   
                        ]
    }   
]

For object detection models each inference result dictionary may contain the following keys:

  • category_id: detected object class numeric ID.
  • label: detected object class label string.
  • score: detected object probability.
  • bbox: detected object bounding box list [xtop, ytop, xbot, ybot].
  • landmarks: optional list of keypoints or landmarks. It is the list of dictionaries, one per each keypoint/landmark.

The landmarks list is defined for special cases like pose detection of face points detection results.
Each landmarks list element is a dictionary with the following keys:

  • category_id: keypoint numeric ID.
  • label: keypoint label string.
  • score: keypoint detection probability.
  • landmark: keypoint coordinate list [x,y].
  • connect: optional list of IDs of connected keypoints.

The object detection keys (bbox, score, label, and category_id) must be ether all present or all absent. In the former case the result format is suitable to represent pure object detection results. In the later case, the landmarks key must be present and the result format is suitable to represent pure landmark detection results such as pose detection. When both object detection keys and the landmarks key are present, the result format is suitable to represent mixed model results, when the model detects not only object bounding boxes, but also keypoints/landmarks within the bounding box.

Example of pure object detection results:

[
    {'category_id': 0, 'label': 'cat', 'score': 0.99, 'bbox': [10, 20, 100, 200]},
    {'category_id': 1, 'label': 'dog', 'score': 0.01, 'bbox': [200, 100, 300, 400]}
]

Example of landmark object detection results:

[
    {
        'landmarks': [
            {'category_id': 0, 'label': 'Nose', 'score': 0.99, 'landmark': [10, 20]},
            {'category_id': 1, 'label': 'LeftEye', 'score': 0.98, 'landmark': [15, 25]},
            {'category_id': 2, 'label': 'RightEye', 'score': 0.97, 'landmark': [18, 28]}
        ]
    }
]

For hand palm detection models each inference result dictionary contains the following keys:

  • score: probability of detected hand.
  • handedness: probability of right hand.
  • landmarks: list of dictionaries, one per each hand keypoint.

Each landmarks list element is a dictionary with the following keys:

  • label: classified object class label.
  • category_id: classified object class index.
  • landmark: landmark point coordinate list [x, y, z].
  • world_landmark: metric world landmark point coordinate list [x, y, z].
  • connect: list of adjacent landmarks indexes.

Example:

[
    {
        'score': 0.99,
        'handedness': 0.98,
        'landmarks': [
            {
                'label': 'Wrist',
                'category_id': 0,
                'landmark': [10, 20, 30],
                'world_landmark': [10, 20, 30],
                'connect': [1]
            },
            {
                'label': 'Thumb',
                'category_id': 1,
                'landmark': [15, 25, 35],
                'world_landmark': [15, 25, 35],
                'connect': [0]
            }
        ]
    }
]

For segmentation models inference result is a single-element list. That single element is a dictionary, containing single key data. The value of this key is 2D numpy array of integers, where each integer value represents a class ID of the corresponding pixel. The class IDs are defined by the model label dictionary.

Example:

[
    {
        'data': numpy.array([
            [0, 0, 0, 1, 1, 1],
            [0, 0, 0, 1, 1, 1],
            [0, 0, 0, 1, 1, 1],
            [2, 2, 2, 3, 3, 3],
            [2, 2, 2, 3, 3, 3],
            [2, 2, 2, 3, 3, 3],
        ])
    }
]

degirum.postprocessor.InferenceResults.type: str property

Inference result type: one of

  • "classification"
  • "detection"
  • "pose detection"
  • "segmentation"

degirum.postprocessor.InferenceResults.__init__(*, model_params, input_image=None, model_image=None, inference_results, draw_color=(255, 255, 128), line_width=3, show_labels=True, show_probabilities=False, alpha=0.5, font_scale=1, fill_color=(0, 0, 0), frame_info=None, conversion, label_dictionary={})

Constructor.

Note

You never construct InferenceResults objects yourself -- the ancestors of this class are returned as results of AI inferences from degirum.model.Model.predict, degirum.model.Model.predict_batch, and degirum.model.Model.predict_dir methods.

Parameters:

Name Type Description Default
model_params ModelParams

Model parameters object as returned by degirum.model.Model.model_info.

required
input_image any

Original input data.

None
model_image any

Input data converted per AI model input specifications.

None
inference_results list

Inference results data.

required
draw_color tuple

Color for inference results drawing on overlay image.

(255, 255, 128)
line_width int

Line width in pixels for inference results drawing on overlay image.

3
show_labels bool

True to draw class labels on overlay image.

True
show_probabilities bool

True to draw class probabilities on overlay image.

False
alpha float

Alpha-blend weight for overlay details.

0.5
font_scale float

Font scale to use for overlay text.

1
fill_color tuple

RGB color tuple to use for filling if any form of padding is used.

(0, 0, 0)
frame_info any

Input data frame information object.

None
conversion Callable

Coordinate conversion function accepting two arguments (x,y) and returning two-element tuple. This function should convert model-based coordinates to input image coordinates.

required
label_dictionary dict[str, str]

Model label dictionary.

{}

degirum.postprocessor.InferenceResults.generate_colors() staticmethod

Generate a list of unique RGB color tuples.

degirum.postprocessor.InferenceResults.generate_overlay_color(model_params, label_dict) staticmethod

Overlay colors generator.

Parameters:

Name Type Description Default
model_params ModelParams

Model parameters.

required
label_dict dict

Model labels dictionary.

required

Returns:

Type Description
Union[list, dict]

Overlay color tuple or list of tuples.

degirum.postprocessor.MultiLabelClassificationResults

Bases: InferenceResults

InferenceResult class implementation for multi-label classification results type

degirum.postprocessor.MultiLabelClassificationResults.image_overlay property

Image with AI inference results drawn. Image type is defined by the selected graphical backend. Each time this property is accessed, new overlay image object is created and all overlay details are redrawn according to the current settings of overlay_*** properties.

degirum.postprocessor.MultiLabelClassificationResults.overlay_show_labels_below property writable

Specifies if overlay labels should be drawn below the image or on image itself

degirum.postprocessor.MultiLabelClassificationResults.__str__()

Convert inference results to string

degirum.postprocessor.SegmentationResults

Bases: InferenceResults

InferenceResult class implementation for segmentation results type

degirum.postprocessor.SegmentationResults.image_overlay property

Image with AI inference results drawn. Image type is defined by the selected graphical backend.

degirum.postprocessor.SegmentationResults.__str__()

Convert inference results to string

degirum.postprocessor.SegmentationResults.generate_overlay_color(model_params, label_dict) staticmethod

Overlay colors generator.

Returns:

Type Description

general overlay color data for segmentation results

degirum.postprocessor.create_postprocessor(*args, **kwargs)

Create and return postprocessor object.

For the list of arguments see documentation for constructor of degirum.postprocessor.InferenceResults class.

Returns:

Type Description
InferenceResults

InferenceResults instance corresponding to model results type.