720p (720 lines progressive) is a progressiveHD signal format with 720 horizontal lines/1280 columns and anaspect ratio (AR) of16:9, normally known as widescreen HD (1.78:1). All major HD broadcasting standards (such asSMPTE 292M) include a 720p format, which has a resolution of 1280×720.
The number720 stands for the 720 horizontalscan lines of imagedisplay resolution (also known as 720 pixels of vertical resolution).[1] Thep stands forprogressive scan, i.e. non-interlaced. When broadcast at 60[note 1] frames per second, 720p features the highesttemporal resolution possible under theATSC andDVB standards. The term assumes awidescreenaspect ratio of16:9, thus implying a resolution of 1280×720px (0.9megapixels).
720i (720 linesinterlaced) 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.[3] No proposed or existing broadcast standard permits 720interlaced lines in a video frame at any frame rate.[4]
Progressive scanning reduces the need to prevent flicker by anti-aliasing single high contrast horizontal lines.[5][6] It is also easier to perform high-quality 50↔60 Hz conversion and slow-motion clips with progressive video.
| Standard | Resolution | Aspect ratio |
|---|---|---|
| HD | 960×720p | 4∶3 |
| HD | 720×960p | 3∶4 |
| HD | 1280×720p | 16∶9 |
| HD | 720×1280p | 9∶16 |
