Class Annotation

brambox/boxes/annotations/annotation.py:13–143

This is a generic annotation class that provides some common functionality all annotations need. It builds upon :class:`~brambox.boxes.box.Box`. Attributes: lost (Boolean): Flag indicating whether the annotation is visible in the image; Default **False** difficult (Boolean)

class Annotation(b.Box):
    """ This is a generic annotation class that provides some common functionality all annotations need.
    It builds upon :class:`~brambox.boxes.box.Box`.

    Attributes:
        lost (Boolean): Flag indicating whether the annotation is visible in the image; Default **False**
        difficult (Boolean): Flag indicating whether the annotation is considered difficult; Default **False**
        occluded (Boolean): Flag indicating whether the annotation is occluded; Default **False**
        ignore (Boolean): Flag that is used to ignore a bounding box during statistics processing; Default **False**
        occluded_fraction (Number): value between 0 and 1 that indicates the amount of occlusion (1 = completely occluded); Default **0.0**
        truncated_fraction (Number): value between 0 and 1 that indicates the amount of truncation (1 = completely truncated); Default **0.0**
        visible_x_top_left (Number): X pixel coordinate of the top left corner of the bounding box that frames the visible part of the object; Default **0.0**
        visible_y_top_left (Number): Y pixel coordinate of the top left corner of the bounding box that frames the visible part of the object; Default **0.0**
        visible_width (Number): Width of the visible bounding box in pixels; Default **0.0**
        visible_height (Number): Height of the visible bounding box in pixels; Default **0.0**

    Note:
        The ``visible_x_top_left``, ``visible_y_top_left``, ``visible_width`` and ``visible_height`` attributes
        are only valid when the ``occluded`` flag is set to **True**.
    Note:
        The ``occluded`` flag is actually a property that returns **True** if the ``occluded_fraction`` > **0.0** and **False** if
        the occluded_fraction equals **0.0**. Thus modifying the ``occluded_fraction`` will affect the ``occluded`` flag and visa versa.
    """
    def __init__(self):
        """ x_top_left,y_top_left,width,height are in pixel coordinates """
        super(Annotation, self).__init__()
        self.lost = False               # if object is not seen in the image, if true one must ignore this annotation
        self.difficult = False          # if the object is considered difficult
        self.ignore = False             # if true, this bounding box will not be considered in statistics processing
        self.occluded_fraction = 0.0   # value between 0 and 1 that indicates how much an object is occluded
        self.truncated_fraction = 0.0   # value between 0 and 1 that indicates how much an object is truncated

        # variables below are only valid if the 'occluded' property is True (occluded_fraction > 0) and
        # represent a bounding box that indicates the visible area inside the normal bounding box
        self.visible_x_top_left = 0.0   # x position top left in pixels
        self.visible_y_top_left = 0.0   # y position top left in pixels
        self.visible_width = 0.0        # width in pixels
        self.visible_height = 0.0       # height in pixels

    @property
    def occluded(self):
        return self.occluded_fraction > 0.0

    @occluded.setter
    def occluded(self, val):
        self.occluded_fraction = float(val)

    @property
    def truncated(self):
        return self.truncated_fraction > 0.0

    @truncated.setter
    def truncated(self, val):
        self.truncated_fraction = float(val)

    @classmethod
    def create(cls, obj=None):
        """ Create an annotation from a string or other box object.