Engineering:720p

From HandWiki
Short description: Video resolution
This chart shows the most common display resolutions, 720p being one of the 16:9 formats shown in blue.

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).[1] 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.[3] No proposed or existing broadcast standard permits 720 interlaced lines in a video frame at any frame rate.[4]

Comparison with interlace scanning

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.

Resolutions

Standard Resolution Aspect ratio
Vintage Small TVs; DVCPROHD[7] 960 × 720 4:3 (effectively 16:9 non-square pixels)
HD (standard) 1280 × 720 16:9
Vertical 720 × 1280 9:16
Letterbox 1080 × 720 3:2

Notes

  1. It is, however, more commonly broadcast at (60/1.001), or precisely 59.940059, matching the NTSC SDTV field rate; this and the 50.00 Hz of PAL are still the second and third highest standard framerates.[2]

See also


References

External links