1080i

1080i-capable plasma tv mounted on a wall

1080i is the shorthand name for a format of high-definition video modes. 1080 denotes the number of horizontal scan lines - also known as vertical resolution - and the letter i stands for interlaced. In the alternate format of high-definition video mode, known as 1080p, the p would stand for progressive scan.^[1][2] 1080i is generally used in place of 1440x1080, at a framerate of 29.97 (30000/1001), while 1080p is usually used in place of 1920x1080 (full HD), at a framerate of 23.976 fps (24000/1001).

1080i is a high-definition television (HDTV) video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a frame resolution of 1920 × 1080 or about 2.07 million pixels.

The field rate of 1080i is typically 60 Hz for NTSC countries (such as United States, Canada and Japan) or 50Hz for PAL/SECAM countries (such as in Europe, Australia, much of Asia, Africa). Because of this the two most common frame rates are 30 frames per second or 25 frames per second. Both variants can be transmitted by both major digital television formats, ATSC and DVB. The frame rate can be implied by the context, while the field rate is generally specified after the letter i, such as "1080i60". The European Broadcasting Union (EBU), prefers to use the resolution and frame rate separated by a slash, as in 1080i/30 and 1080i/25, likewise 480i/30 and 576i/25^{[citation needed]}.

1080i is directly compatible with CRT-based HDTV sets. 1080i is displayed as is on 1080p-based televisions and is compatible with newer 720p-based televisions, but must be deinterlaced first in order to be displayed on those sets. A panel size used in mid-range HDTVs is 1366 x 768; these are often advertised as 1080i "compatible" or "HD ready" - however these HDTVs, while accepting a 1080i signal scales it down to the panel size of 1366x768 as these are physically incapable of displaying 1877x1000 (the actual displayed resolution of a 1920x1080 source) resolutions.^[3]

See also

Television portal

• 1080p

References

External links

• High Definition (HD) Image Formats for Television Production (EBU technical publication)
• 720p vs. 1080p HDTV: The final word - CNET Review - December 5, 2007

v • d • e Digital Video Resolutions Designation Usage Examples Definition (lines) Rate (Hz) Interlaced (fields) Progressive (frames) Low; MP@LL LDTV, VCD 240; 288 (SIF)   24, 30; 25 Standard; MP@ML SDTV, SVCD, DVD, DV 480 (NTSC, PAL-M) 60 24, 30 576 (PAL, SECAM) 50 25 Enhanced EDTV 480; 576   60; 50 High; MP@HL HDTV, Blu-ray Disc, HDV 720   24, 30, 60; 25, 50 1080 50, 60 24, 30; 25 This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen or pixel shape (aspect ratio) of these formats, which is either 4:3, or 16:9.