def prepare_binary(fn):
    seg = (np.squeeze(imread(fn)) > bw_th)
    seg = remove_small_objects((seg > 0), min_size=min_obj_size)
    return seg
def prepare_binary(fn):
    seg = (np.squeeze(imread(fn)) > bw_th)
    seg = remove_small_objects((seg > 0), min_size=min_obj_size)
    return seg