720p is a progressive HD signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HD (1.78:1). All major HD broadcasting standards (such as SMPTE 292M) include a 720p format, which has a resolution of 1280×720p.
The number 720 stands for the 720 horizontal scan lines of image display resolution (also known as 720 pixels of vertical resolution). The p stands for progressive scan, i.e. non-interlaced. When broadcast at 60[note 1] frames per second, 720p features the highest temporal resolution possible under the ATSC and DVB standards. The term assumes a widescreen aspect ratio of 16:9, thus implying a resolution of 1280×720 px (0.9 megapixels).
720i (720 lines interlaced) is an erroneous term found in numerous sources and publications. Typically, it is a typographical error in which the author is referring to the 720p HDTV format. However, in some cases it is incorrectly presented as an actual alternative format to 720p. No proposed or existing broadcast standard permits 720 interlaced lines in a video frame at any frame rate.
Comparison with 1080i and 1080p
Progressive scanning reduces the need to prevent flicker by anti-aliasing single high contrast horizontal lines. It is also easier to perform high-quality 50<-->60 Hz conversion and slow-motion clips with progressive video.
|Vintage Small TVs; DVCPROHD||960 × 720||4:3, 16:9|
|HD (standard)||1280 × 720||16:9|
- ^ "720p – AfterDawn: Glossary of technology terms & acronyms".
- ^ Hoffner, Randy (2008-01-09). "Will the End of NTSC Be the End of 59.94?". TVTechnology. Retrieved 2010-10-08.
- ^ Briere, Daniel; Patrick Hurley (2006). HDTV for Dummies. For Dummies. p. 13. ISBN 9780470096734.
- ^ "ATSC Standard: Video System Characteristics of AVC in the ATSC Digital Television System" (PDF). 2008-07-29. Archived from the original (PDF) on 2012-10-04. Retrieved 2011-07-24.
- ^ "720p". AfterDawn. 2010-08-10. Retrieved 2010-10-08.
- ^ "720p". CNET Glossary. Archived from the original on 2010-09-30. Retrieved 2010-10-08.