HDTV-an introduction

HDTV stands for High Definition Television, and if you live in USA, Australia, Japan or you may already have experienced. There are three key differences between what has become known as a standard definition TV, i.e. regular NTSC, PAL or SECAM, and HDTV. The three differences are; an increase in image resolution in 16: 9 widescreen as standard and the ability to support multichannel audio such as Dolby Digital.

The most important aspect of HDTV and what gives it the name is a higher resolution. Standard-definition NTSC broadcasts have 525 horizontal lines and PAL broadcasts are slightly better at 625 lines. In both these systems, however, the actual number of rows is used to display the image, known as active lines is less than that. In addition, both the PAL and NTSC systems are interlaced, i.e., each frame is spit into two camps, a field is the odd lines and the other is the even lines. Each frame is displayed alternately and our brain puts them together to create a complete picture of each frame. This has a negative effect on image quality.

HDTV is broadcast in one of two formats; 720 p and 1080i. The numbers refer to the number of lines of vertical resolution and letters refer to the signal to progressive scan, ' p ', or ' i ' interlace. Progressive scan means that each frame is shown in its entirety, rather than being divided into fields. Both systems are significantly better quality than PAL or NTSC broadcasts.

HDTV uses 16: 9 widescreen aspect ratio, as well as widescreen images are transmitted so correctly and not Letterbox or panned and scanned. Multichannel Dolby Digital Audio can be transmitted as part of an HDTV signal, so if you have a surround sound speakers, you can use to listen to TV rather than just DVD.

To receive a broadcast HDTV is necessary or a TV with a tuner HDTV or an HDTV receiver that can pick up off air HDTV channels, or via cable or satellite HDTV as. It is also necessary to live are where HDTV channels are transmitted, or distributed via cable or satellite.

HDTV is currently widespread in Japan, and is commonplace in the United States, becoming with most major networks distribute HDTV versions of their popular content. The 2005 Superbowl has led to a strong increase in demand for HDTV and Fox Sports cable companies scrambled to add to their bid in the period up to the game. In Australia, uptake was slow initially but HDTV has increased significantly since 2003.

The situation in Europe is not so bright. There is only one company of HDTV broadcasting in Europe, Euro1080-, and has only two HDTV channels in 1080i format. Euro1080HDe shows large cultural and sporting events to cinema and clubs in Europe, while HD1 broadcasts, opera, rock music and lifestyle programmes via satellite homes in Europe. British satellite broadcaster Sky, which is owned by Rupert Murdoch's Fox proprieter, announced plans to send some HDTV content in 2006. The BBC has also made noises about broadcasting HDTV programmes (some programs already film in HD).

However, it will be a while before it reaches HDTV in Europe with the rest of the world. The controversy created by the confirmation of the Government of the United Kingdom plans to start turning off the analogue transmitters in 2008 showed how many people have yet to make the transition to DVB-t. That will be used as an argument to prove that there is no appetite in the United Kingdom for another major change in TV broadcasting, particularly as most people think they have already ' digital TV ' in the form of DVB-t.

Since television was invented by a Briton, and Europe led the way with PAL for so long, this is a rather sorry state of affairs.

Kenny Hemphill is the Publisher of The Tuner HDTV -an essential guide for HDTV.