Metanoia is a compilation album by British progressive rock band Porcupine Tree, first released on 10" double-vinyl on 7 December 1998, in a limited run of 1,000 copies. It is mostly made up of improvisations recorded during the Signify sessions, some of which were later shaped into songs. To help deter secondary- and black-market sales, the album was released on CD in December 2001 and re-issued again in 2006; it includes extra, previously released tracks from singles that were sequenced where they were extracted from the longform jams.