The garbage mattes (and emperor's slugs) do not need to be removed - on a properly exposed transfer and a correctly calibrated display you won't be able to see them, just as they were not visible in the cinema.

The mattes stood out on the early video transfers becasue the laserdisc and VHS releases were horrifically over-exposed - they have that washed-out look with an overly bright midground. The THX laserdisc master (used on the GOUT) was better, but is still too bright.

The mattes should not be visible on the 2004 DVD (which is actually underexposed - too dark - with crunched blacks and detail lost in the shadows) but people still see them because they have their TVs left in the overbright, oversharp factory-preset mode.