A pre-filter for reducing visibility of top and bottom bars on EDTV

Abstract

This paper proposes a method reducing the visibility of VT (Vertical-Temporal) helper signals multiplexed in top and bottom bars on EDTV. In the method, a progressively-scanned signal is pre-filtered in the vertical-temporal frequency domain, then the VT signal is produced. The energy of the VT signal decreases. Therefore its visibility can be reduced. The pre-filter characteristics need not be regulated, and the pre-filter can be discarded after EDTV receivers become popular.