(a) Notwithstanding any other provision of law to the contrary, this subtitle shall be applied retroactively to include a person who:
(1) is under the custody or supervision of a supervising authority on October 1, 2010;
(2) was subject to registration under this subtitle on September 30, 2010;
(3) is convicted of any felony on or after October 1, 2010, and has a prior conviction for an offense for which registration as a sex offender is required under this subtitle; or
(4) was convicted on or after October 1, 2010, of a violation of § 3–324 of the Criminal Law Article, regardless of whether the victim was a minor.
(b) The term of registration for a sex offender registered under subsection (a) of this section shall be calculated from the date of release.