Initial revision

Signed-off-by: helio <helio@roboken.esys.tsukuba.ac.jp>
Dithering-based bit string construction

Signed-off-by: helio <helio@roboken.esys.tsukuba.ac.jp>
Added license terms

Signed-off-by: helio <helio@roboken.esys.tsukuba.ac.jp>