spread spectrum\fplot.m ...............\get_random_sequence.m ...............\imlogpolar.m ...............\iterplot.m ...............\lena512.bmp ...............\logis.m ...............\logisnew.m ...............\logstep.m ...............\parse_inputs.m ...............\tri_sequence_logis.m ...............\w32.bmp ...............\ww32.bmp spread spectrum