A video signal based on an NTSC system is converted into a signal for EDTV. The converted signal is subjected to signal compression in a signal compression ratio of 910/m times. The compressed signal is added with a pedestal level signal and a side level signal. The combined signal is converted into...http://www.google.de/patents/US5134479?utm_source=gb-gplus-sharePatent US5134479 - NTSC high resolution television converting apparatus for converting television signals of an NTSC system into high resolution television signals
