def obj_fpr(result, reference, connectivity=1):
    """
    The false positive rate of distinct binary object detection.
    
    The false positive rates gives a percentage measure of how many distinct binary
    objects in the second array do not exists in the first array. A partial overlap
    (of minimum one voxel) is here considered sufficient.
    
    In cases where two distinct binary object in the second array overlap with a single
    distinct object in the first array, only one is considered to have been detected
    successfully and the other is added to the count of false positives.
    
    Parameters
    ----------
    result : array_like
        Input data containing objects. Can be any type but will be converted
        into binary: background where 0, object everywhere else.
    reference : array_like
        Input data containing objects. Can be any type but will be converted
        into binary: background where 0, object everywhere else.
    connectivity : int
        The neighbourhood/connectivity considered when determining what accounts
        for a distinct binary object. This value is passed to
        `scipy.ndimage.morphology.generate_binary_structure` and should usually be :math:`> 1`.
        The decision on the connectivity is important, as it can influence the results
        strongly. If in doubt, leave it as it is.
        
    Returns
    -------
    tpr : float
        A percentage measure of how many distinct binary objects in ``results`` have no
        corresponding binary object in ``reference``. It has the range :math:`[0, 1]`, where a :math:`0`
        denotes an ideal score.
        
    Raises
    ------
    RuntimeError
        If the second array is empty.
    
    See also
    --------
    :func:`obj_tpr`
    
    Notes
    -----
    This is not a real metric, as it is directed. Whatever array is considered as
    reference should be passed second. A perfect score of :math:`0` tells that there are no
    distinct binary objects in the second array that do not exists also in the reference
    array, but does not reveal anything about objects in the reference array also
    existing in the second array (use :func:`obj_tpr` for this).
    
    Examples
    --------
    >>> arr2 = numpy.asarray([[1,0,0],[1,0,1],[0,0,1]])
    >>> arr1 = numpy.asarray([[0,0,1],[1,0,1],[0,0,1]])
    >>> arr2
    array([[1, 0, 0],
           [1, 0, 1],
           [0, 0, 1]])
    >>> arr1
    array([[0, 0, 1],
           [1, 0, 1],
           [0, 0, 1]])
    >>> obj_fpr(arr1, arr2)
    0.0
    >>> obj_fpr(arr2, arr1)
    0.0
    
    Example of directedness:
    
    >>> arr2 = numpy.asarray([1,0,1,0,1])
    >>> arr1 = numpy.asarray([1,0,1,0,0])
    >>> obj_fpr(arr1, arr2)
    0.0
    >>> obj_fpr(arr2, arr1)
    0.3333333333333333
    
    Examples of multiple overlap treatment:
    
    >>> arr2 = numpy.asarray([1,0,1,0,1,1,1])
    >>> arr1 = numpy.asarray([1,1,1,0,1,0,1])
    >>> obj_fpr(arr1, arr2)
    0.3333333333333333
    >>> obj_fpr(arr2, arr1)
    0.3333333333333333
    
    >>> arr2 = numpy.asarray([1,0,1,1,1,0,1])
    >>> arr1 = numpy.asarray([1,1,1,0,1,1,1])
    >>> obj_fpr(arr1, arr2)
    0.0
    >>> obj_fpr(arr2, arr1)
    0.3333333333333333
    
    >>> arr2 = numpy.asarray([[1,0,1,0,0],
                              [1,0,0,0,0],
                              [1,0,1,1,1],
                              [0,0,0,0,0],
                              [1,0,1,0,0]])
    >>> arr1 = numpy.asarray([[1,1,1,0,0],
                              [0,0,0,0,0],
                              [1,1,1,0,1],
                              [0,0,0,0,0],
                              [1,1,1,0,0]])
    >>> obj_fpr(arr1, arr2)
    0.0
    >>> obj_fpr(arr2, arr1)
    0.2    
    """
    _, _, _, n_obj_reference, mapping = __distinct_binary_object_correspondences(reference, result, connectivity)
    return (n_obj_reference - len(mapping)) / float(n_obj_reference)