Harmy said:
The problem here is, that the garbage mattes are actually visible in the bright areas of that shot (on the star-destroyer) - slightly crushing the dark areas in space shots (actually increasing contrast - lowering contrast makes the mates more visible) usually takes care of the garbage mattes on the black backdrop of space but there is no practical way I know of to get rid of them from bright areas.
Yes, not to mention that the hull of the ISD is far more complex than space shots. I watched the scene again and only the darker starboard side of the ISD seems to affected. Would it be possible to isolate the most visible garbage mattes and to lower their brightness frame by frame?