def __init__(self):
    """Create a new ImageObjectDetection instance."""
    super(sppasImageObjectDetection, self).__init__()
    self._extension = ''
    self._detector = None

def get_nb_recognizers(self):
    """Return the number of initialized object recognizers."""
    if self._detector is None:
        return 0
    return len(self._detector)

def get_nb_enabled_recognizers(self):
    """Return the number of enabled object recognizers."""
    nb = 0
    if self._detector is not None:
        for detector in self._detector:
            if self._detector[detector][1] is True:
                nb += 1
    return nb

def get_recognizer_names(self):
    """Return the name of all the initialized recognizers."""
    if self._detector is None:
        return list()
    return [self._detector[d][0] for d in self._detector]

def get_enabled_recognizer_names(self):
    """Return the name of all the initialized recognizers. """
    r = list()
    if self._detector is not None:
        for d in self._detector:
            if self._detector[d][1] is True:
                r.append(self._detector[d][0])
    return r

def get_recognizer(self, name):
    """Return the recognizer of the given name or None.

        :param name: (str) Name of a recognizer.
        :return: (BaseObjectsDetector or None)

        """
    if self._detector is not None:
        for detector in self._detector:
            if self._detector[detector][0] == name:
                return detector
    return None

def enable_recognizer(self, name, value=True):
    """Enable or disable a recognizer.

        :param name: (str) Name of a recognizer.
        :param value: (bool)

        """
    value = bool(value)
    if self._detector is not None:
        for detector in self._detector:
            if self._detector[detector][0] == name:
                self._detector[detector] = (name, value)
                return value
    return False

@staticmethod
def extensions():
    """Return the whole list of supported extensions in lower case."""
    return list(sppasImageObjectDetection.DETECTORS.keys())

def load_model(self, model, *args):
    """Instantiate detector(s) from the given models.

        Calling this method invalidates the existing detectors.
        All instantiated detectors are enabled by default.
        The min ratio is divided by the number of detectors.

        :param model: (str) Default required model filename
        :param args: Other models to load in order to create object detectors
        :raise: IOError, Exception

        """
    self._detector = dict()
    detector = sppasImageObjectDetection.create_recognizer_from_extension(model)
    detector.load_model(model)
    detector_name = os.path.basename(model)
    self._detector[detector] = (detector_name, True)
    for filename in args:
        try:
            detector = sppasImageObjectDetection.create_recognizer_from_extension(filename)
            detector.load_model(filename)
            detector_name = os.path.basename(filename)
            self._detector[detector] = (detector_name, True)
        except Exception as e:
            logging.error(e)
    for detector in self._detector:
        detector.set_min_ratio(self.get_min_ratio() / len(self._detector))

@staticmethod
def create_recognizer_from_extension(filename):
    """Return an object detector according to a given filename.

        Only the extension of the filename is used.

        :param filename: (str)
        :return: BaseObjectsDetector
        :raise: IOError

        """
    extension = os.path.splitext(filename)[1]
    extension = extension.lower()
    if extension in sppasImageObjectDetection.extensions():
        return sppasImageObjectDetection.DETECTORS[extension]()
    raise IOExtensionError(filename)

def filter_overlapped(self, overlap=50.0, norm_score=True):
    """Remove overlapping detected objects and too small scores.

        It is supposed that the scores are already sorted by scores.

        :param overlap: (float) Minimum percentage of overlapped area to invalidate an object
        :param norm_score: (bool) Normalize the score of the detected objects by the number of detectors

        """
    overlap = float(overlap)
    if overlap < 0.0 or overlap > 100.0:
        raise IntervalRangeException(overlap, 0.0, 100.0)
    detected = list()
    for coord in self._coords:
        c = coord.copy()
        score = c.get_confidence()
        nb = self.get_nb_enabled_recognizers()
        if norm_score is True and nb > 1:
            c.set_confidence(score / float(nb - 1))
        detected.append(c)
    for i, coord in enumerate(detected):
        for j, other in enumerate(detected):
            if other.get_confidence() == 0.0 or i == j:
                continue
            if coord.intersection_area(other) > 0:
                area_o, area_s = coord.overlap(other)
                if area_o > overlap:
                    c = min(1.0, other.get_confidence() + coord.get_confidence())
                    coord.set_confidence(c)
                    other.set_confidence(0.0)
                '\n                    # reject "i" object if more than 50% of its area is\n                    # overlapping "j" and "j" has a significant bigger \n                    # dimension, either w or h or both\n                    if area_s > overlap and (coord.w < other.w or coord.h < other.h):\n                        c = min(1., other.get_confidence() + coord.get_confidence())\n                        coord.set_confidence(0.)\n                        other.set_confidence(c)\n                    '
    self._coords = [c for c in detected if c.get_confidence() > self.get_min_score()]

def _detection(self, image):
    """Determine the coordinates of all the detected objects.

        No filter nor sort is applied. Results are "as it".

        :param image: (sppasImage or numpy.ndarray)

        """
    if self.get_nb_enabled_recognizers() == 0:
        raise sppasError('None of the recognizers is enabled. At least one is required...')
    for detector in self._detector:
        if self._detector[detector][1] is True:
            detector.detect(image)
            for coord in detector:
                self._coords.append(coord)