def find_cntrs(boxes):
    """Get the centers of the list of boxes in the input.

    Parameters
    ----------
    boxes : list
        The list of the boxes where each box is
        [x,y,width,height] where x,y is the coordinates
        of the top-left point

    Returns
    -------
    list
        Centers of each box where each row is a list of
        two float numbers (x,y).

    """
    # box is : x,y,w,h
    centers = []
    for box in boxes:
        centers.append([(box[0]+(box[2]/2)),(box[1]+(box[3]/2))])
    return centers