Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!oliveb!sun!vector!poynton From: poynton@vector.Sun.COM (Charles A. Poynton) Newsgroups: comp.graphics Subject: Re: HDTV request for info Summary: SMPTE 240M HDTV has 1035 lines. North American 1050/59.94 proposals have only 966. Square pixels can be achieved by various means. Message-ID: <105770@sun.Eng.Sun.COM> Date: 18 May 89 23:54:58 GMT References: <9052@polya.Stanford.EDU> <5300004@ux1.cso.uiuc.edu> Sender: news@sun.Eng.Sun.COM Reply-To: poynton@sun.com (Charles A. Poynton) Organization: Sun Microsystems, Mountain View Lines: 31 Phil@ux1.cso.uiuc.edu asked a few weeks ago: > Of the 1125 scanned lines in the Japanese HDTV standard, how many > of them are actually displayed? In the 1125/60 system, according to SMPTE 240M, 1035 lines contain picture. > It would be nice if this number is at least 1024 for computer > applications. Indeed it would. A major drawback of all of the 1050/59.94 systems proposed for broadcast in North America is that they have only 966 picture lines, inherited from twice NTSC. > I understand the aspect ratio is 3:2 so if we can get square > pixels, we can have 1536 pixels horizontally, maybe. The picture aspect ratio of virtually all HDTV systems is 16:9, according to the international CCIR Report 801-1. Using 1080 picture lines instead of 1035 would achieve square pixels with the proposed 1920 samples per line. Alternatively, square pixels could be achieved with 1035 lines of 1840 samples. C. ----- Charles A. Poynton Sun Microsystems Inc. 2550 Garcia Avenue, MS 8-04 415-336-7846 Mountain View, CA 94043 ----