High definition TV – new television
HDTV was presented for the first time over 20 years ago in Japan. In the future it will become the system of all broadcasts and will be as popular as the current PAL system, which we have adopted for our home televisions for close to 60 years. Aside from PAL it will also replace the remaining television systems – NTSC and SECAM. What differences between the traditional signal and the new standard are there in choosing something from television programming instead of cinema or home cinema using a DVD player?
Full assessment and appreciation of the differences between PAL and HDTV signals demands the proverbial learning from your own experiences, which is third generation television. We still haven’t learnt the merits of HDTV in the privacy of our own homes, because still none of the Polish broadcasters have decided to switch the signal standard. However, what remains for us at the moment is a visit to a supermarket stocking electrical equipment or to a specialist audio-video equipment fair, where we could watch programs at the new standard on televisions adapted to HDTV. For those who can’t wait for refined experiences for their ears and eyes, a real treat awaits. One of the largest cinema networks in Poland will show the World Cup in Germany in 2006 with the HDTV system.
Not everyone knows all the information which in the future could allow the viewer to be more aware and at the same time could broaden perception of the receipt of HDTV signal. And so the high digital quality, using a high resolution imaged recorded and displayed, is the fundamental feature differentiating High Definition from other standards. The viewer can see more detail. The traditionally applied PAL system is characterised by a resolution of 720x576 pixels. The second parameter provided is the number defining the amount of the image’s horizontal lines. The value of this figure allows awareness of the difference in parameters of an analogue and digital image. The minimum value of these coordinates for HDTV is 720, and the maximum 1080. The minimum defined resolution for the HD standard is 1280x720, which gives the figure of 921,600 pixels. In the case of the maximum resolution of so-called full HD, 1920x1080, the number of pixels is 2,073,600 and means almost six times greater amount of information contained in the image.
High Definition Television is characterised by two types of resolution – progressive (progressive scan – p) and interlaced (interlaced – i).
At present, the HDTV standard has 5 approved formats:
720p (1280x720) – 24 frames per second
720p (1280x720) – 30 frames per second
720p (1280x720) – 60 frames per second
1080i (1920x1080)
1080p (1920x1080)
The difference between these consists of the means of broadcasting the signal (scanning lines and their display on the screen). In the case of interlaced format, the image transmitted to the receiver firstly fills the odd-numbered lines, and then the even. All lines are only full after two passes. If we talk about progressive scanning, here all lines are filled in order (720), so as to create one full frame of image. The visual senses connected with the resolution and its type are above all the high quality of the image, which is distinct, vivid and stable (without flickering).
An image in the panoramic format 16:9 is another merit of HDTV. For comparison, the traditional PAL format has the ratio 4:3. Thanks to this parameter, the image under the HDTV standard assumes a much wider plane and on the screens of our receivers we can see more detail, which with PAL signal receivers we were not in a position to see. It is worth also turning our attention to colour, which is very realistic under the standard of third generation television. The source of sound through the surround system, which until now has never been available in television standards, is an undoubted merit of HDTV. The enhancement of signal at this feature is made possible in a home cinema system by a receiver with Dolby Digital 5.1 surround sound.
High Definition Television is still not well known in Poland, which is quite surprising considering its features. The digital platform Cyfra+ undertook tests of broadcasting a signal at the new standard. TVP has also declared its readiness to broadcast selected programmes in this new quality.
Around the world, the transition to High Definition standard has taken place very dynamically. The HDTV format is already universal in Japan, Korea and China (all Japanese TV channels, Korean Broadcasting and Chinese CCTV), Australia and in North and South America (HD net, TV Azteca-Mexico, TV Globo-Brazil).
On the European market, inhabitants of Holland will be able to enjoy high definition television as the first to introduce the HDTV standard on our continent thanks to an agreement between the companies Phillips and UPC. With our western neighbours, the stations ProSieben, Premiere and Sat 1 have started to transmit programs with HDTV technology. Further broadcasters who have announced the initiation of high definition television are BSkyB in Great Britain (22nd May 2006), CanalSat in France and Sky Italy. They will transmit the World Cup in Germany in 2006 in this format.