CTP removing overlays embedded in high bits of pixels

[Jeskynar]

Hi

Can I just check on the behaviour of CTP when it is configured to remove overlays (60xx groups) -- the only thing that does is remove all tags which are in 60xx groups?

This means that if overlays are embedded in the high bits of the image pixels then these overlays will still be present even after CTP anonymisation? I realise the tags which describe them will have been removed but a determined person could decode the high bits of the image pixels and render the overlays?  Or does CTP do some extra work to re-encode the image pixels with high bits set to zero?

Andrew