720p
720p (720 lines progressive) 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 ×ばつ720.
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 ×ばつ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
[edit ]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 to 60 Hz conversion and slow-motion clips with progressive video.
Resolutions
[edit ]| Standard | Resolution | Aspect ratio |
|---|---|---|
| HD | ×ばつ720p | 4∶3 |
| HD | ×ばつ960p | 3∶4 |
| HD | ×ばつ720p | 16∶9 |
| HD | ×ばつ1280p | 9∶16 |
Notes
[edit ]See also
[edit ]
References
[edit ]- ^ "720p – AfterDawn: Glossary of technology terms & acronyms".
- ^ Hoffner, Randy (2008年01月09日). "Will the End of NTSC Be the End of 59.94?". TVTechnology. Retrieved 2010年10月08日.
- ^ 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年07月29日. Archived from the original (PDF) on 2012年10月04日. Retrieved 2011年07月24日.
- ^ "720p". AfterDawn. 2010年08月10日. Retrieved 2010年10月08日.
- ^ "720p". CNET Glossary. Archived from the original on 2010年09月30日. Retrieved 2010年10月08日.