Delete the existed ID pixels who's in nparray idx_array

    After computing pixels connectivity, we get a set of pixels which have
    connectivity and have the same ID. We get these pixels positions set as
    nparray idx_array as well. Then we need to remove these pixels from all
    of the given value's pixels and compute the connectivity of rest given
    value's pixels.

    Args:
        givenvalue_pixels_positions: given value's pixels positions set from
        last time's computing connectivity.
        idx_array: pixels position set which have the same ID(means same that
        these pixels have connectivity)

    Return:
        givenvalue_pixels_positions: given value's pixels positions set
        after deleting the existed ID pixels.

def remove_existID_pixels(givenvalue_pixels_positions, idx_array):
    """Delete the existed ID pixels who's in nparray idx_array

    After computing pixels connectivity, we get a set of pixels which have
    connectivity and have the same ID. We get these pixels positions set as
    nparray idx_array as well. Then we need to remove these pixels from all
    of the given value's pixels and compute the connectivity of rest given
    value's pixels.

    Args:
        givenvalue_pixels_positions: given value's pixels positions set from
        last time's computing connectivity.
        idx_array: pixels position set which have the same ID(means same that
        these pixels have connectivity)

    Return:
        givenvalue_pixels_positions: given value's pixels positions set
        after deleting the existed ID pixels.
    """
    # We need to give List existID_pixels a 0 value to avoid the error:
    # cannot compute fingerprint of empty list
    existID_pixels = [0]
    for i in range(givenvalue_pixels_positions.shape[0]):
        for j in range(idx_array.shape[0]):
            if ((givenvalue_pixels_positions[i, 0] == idx_array[j, 0]) and
                    (givenvalue_pixels_positions[i, 1] == idx_array[j, 1])):
                existID_pixels.append(i)
    givenvalue_pixels_positions = np.delete(givenvalue_pixels_positions,
                                            existID_pixels, 0)
    return givenvalue_pixels_positions