as far as i know, the image corrections function in scribus should be ok.
i've never heard anybody complaining about them.
but i must admit, that i've never heard of anybody using them in a "serious" workflow either.
personally, i always process the linked files outside of scribus.
this has the nice side effect of making scribus snappier, since it does not have to re-calculate the images over and over!
but, if you want to give it a try, please go ahead! and report the results to this forum so that we know better!
good luck
a.l.e