There were four major HDTV systems tested by SMPTE in the late 1970s, and in 1979 an SMPTE study group released A Study of High Definition Television Systems:
'এ স্টাডি অব হাই ডেফিনিশন টেলিভিশন সিস্টেমস' কে প্রকাশ করেছেন?
an SMPTE study group