Method of reproducing transparent masters

摘要

A master to be copied has a picture in which a dark region and a light region are located one behind the other. The two regions are separated by a light/dark transition where a halo can develop on copies of the master. Prior to copying, the master is scanned and the resulting data used to produce a mask for the master. The mask has a light/dark transition corresponding to the light/dark transition of the master. However, the light/dark transition of the mask is shifted relative to the light/dark transition of the master. The shift is such that, when the mask is superimposed on the master, the light/dark transition of the mask is superimposed on a region of the master which reduces the visibility of the halo. The master is copied following masking.