YCM physically cleaned up the original negative by washing it, and fixing it frame by frame scanning it into a computer recompositing all the original film elements that were stored in the lucasfilm archives. Lowry did a digital restoration with their bank of g5 computers and their own algorithm program, but as they only had three months it was a rush job.
John Lowry in an interview explained that some many new prints had to be struck from the new masters created for the special edition in 1997 that the films were even further degraded, saying that the popularity of the flms led to their own detriment.