What is the difference between SD and HD video?

Answer 1

High definition television uses far more data to create images than standard definition. It's about 5 times the amount of data in fact. The higher data rate allows the image to be generated with more pixels to produce a crisper image.

In North America, standard definition has always been broadcast with a 4:3 aspect ratio. In Europe, 16:9 aspect ratios were introduced in the early 1990s so the majority of European content has been created in wide screen format for a number of years.

HD television is always 16:9 and there is no standard for 4:3 ratio when using HD.

The standard definition resolutions are as follows:

NTSC (North America) is 640 x 480 pixels with a 4:3 aspect ratio

PAL (Europe) is 720 x 576 with either a 4:3 aspect ratio or 16:9 aspect ratio

High definition signals are:

1280 x 720 pixels with a 16:9 aspect ratio

1920 x 1080 pixels, also using 16 : 9 aspect ratio.

Answer 2

To qualify as "HD" the video must have a vertical resolution greater then or equal to 720.

ex. 720p, 1080i, 1080p.

Video with a lower resolution (ex. 480) can still be digital but not qualify as "High Definition". Here is more from WikiAnswers contributors: *

Standard digital video is what you would find on a DVD, in that it contains a string of `bits', or 1's and 0's, which are encoded to produce a video picture. HD video contains 5 times the amount of information, contributing to the higher `resolution'.

For example, a standard DVD would contain 480 lines in the image. (There are actually 525 lines in a standard definition signal, but only 480 of them are used to create the image) A HD image will be around 1080 lines. More pixels in each line means that the amount of data required is approximately 5 times that of a standard definition image. What this does of course, gives you a much sharper and detailed picture.

It's the `short course', but I hope it helps to answer your question.

Answer 3

High definition television is defined by the HDTV standards of 1080 line and 720 line images. Any image format that uses these line counts is regarded as HD. 1080i (interlaced image) and 1080p (progressive scan) are both HD signals even though 1080p uses twice the data rate. Television broadcasters offering HD content will always use one of those two line counts. 1035 line was also used for a short time but is not now used by any mainstream broadcaster. Higher resolutions are used in some production environments with 2000 and even 4000 lines being used. These are exclusively used away from the broadcast chain such as film production. Even if the higher resolutions are used within a television production, the resolution is used only for editing purposes and the production will then be broadcast in 1080 or 720 line formats. It is worth noting that 1080p is not currently used for television broadcast although it can be found on DVDs and other graphics devices such as PCs for example. It is expected that 1080i will remain the HD standard for broadcast for a number of years as live production equipment supporting 1080p is not readily available and the bandwidth required for broadcast is prohibitive at present.

Answer 4

SD is when you look at potatoes and its blurry. In HD, I can see the spuds.

Answer 5

High Definition