Updates the feature descriptor to ensure that the function is externally...

import cv2

from scipy.misc import bytescale

try:

    import cyvlfeat as vl

    vlfeat = True

    pass

def extract_features(array, method='orb', extractor_parameters=None):

def extract_features(array, method='orb', extractor_parameters={}):

    """

    This method finds and extracts features from an image using the given dictionary of keyword arguments.

    The input image is represented as NumPy array and the output features are represented as keypoint IDs

    array : ndarray

            a NumPy array that represents an image

    detector : {'orb', 'sift', 'fast', 'surf'}

              The detector method to be used

    method : {'orb', 'sift', 'fast', 'surf', 'vl_sift'}

              The detector method to be used.  Note that vl_sift requires that

              vlfeat and cyvlfeat dependencies be installed.

    extractor_parameters : dict

                           A dictionary containing OpenCV SIFT parameters names and values.

    if 'vl_' in method:

        return detectors[method](array, compute_descriptor=True, float_descriptors=True, **extractor_parameters)

    else:

        # OpenCV requires the input images to be 8-bit

        if not array.dtype == 'int8':

            array = bytescale(array)

        detector = detectors[method](**extractor_parameters)

        return detector.detectAndCompute(array, None)