High Definition Television

Akronim: HDTV

HDTV
High Definition Television. A television display standard providing much
better picture quality than a standard (non-HD) television.There are a number of different formats
for high-definition, a TV which supports any one of these standards can claim
to be high-definition (or HD Ready):
720p
1080i
1080p
The number part specifies the number of vertical lines. 720p is 720
vertical lines (and 1280 lines horizontally). 1080i and 1080p are both 1080
vertical lines (and 1920 lines horizontally). HDTV are always widescreen, so
having a horizontal to vertical ratio of 16:9
The letter "p" or "i" denotes "progressive" or "interlaced" respectively,
which denotes how the picture is built up. With interlaced the image is
built up in two passes, with every other line updated. With progressive scan
a complete image is transmitted in each frame. What this means in practice
is that progressive gives a smoother picture, especially where there is
notion.


Occasionally the format may be expressed with an additional number after
the "p" or "i". Where this is given this is the frame frame, i.e. the number
of frames per second. Typically 720p is 60 frames per second (so 720p60 in
full), and 1080i and 1080p are 50 frames per second.
cf SDTV, NTSC,
PAL, EDTV
Relevant links:www.hdtvuk.tv - HDTV relevant news.

Inne definicje z Informatyki na literę H.