def total_images_searched(st):
    """ Number of images formed (trials) in all segments, dms, dts.
    """
    si = 0
    for segment in range(st.nsegment):
        for dmind in range(len(st.dmarr)):
            for dtind in range(len(st.dtarr)):
                si += len(st.get_search_ints(segment, dmind, dtind))
    return si
