There is a great debate around the issue of HD Televisions and which digital HD format is ideal for global adoption, although most broadcasting and media companies are already utilizing 720p and 1080p Full HD to broadcast and create content. Digital HD TV broadcasts take less bandwidth than Analogue HDTV broadcasts because they utilize video compression and transmit their signal as data bits over the air. This allows less bandwidth to be used as the signal is sent in small sizes rather than as a large chunk of data. Compare to Analogue HD broadcasts which transmit over the air using one signal and uncompressed. This makes the quality of the pictures difficult to receive and the prospect of broadcasting information at higher resolutions would require a larger bandwidth.
Digital broadcasting on the other hand can utilize the same signal and broadcast up to seven separate channel feeds in addition to more channels of audio to produce the high definition experience.
The process of video compression and reproduction is borrowed from computer technology and allows HD televisions to decompress and reproduce picture images and videos using their own built in picture rendering engines rather than relying on the feed it is receiving over the air. Also analogue broadcasting relied on an image scanning technology called interlaced scanning, which sends out one image using two different signal speeds and stitches the images back together without affecting the picture quality. This type of technology relies a lot on the motion perception of a viewer’s eyes. With digital technology, a newer technology was employed which had already been successful on DVD player systems and computer monitors. The technology called progressive scanning, it sends out the complete image on one signal but in data bits or smaller sizes allowing the receiving display to build and construct the image together. Today most broadcasters and film makers use progressive scanning because of its compression of video data and the technology employed. On most HD formats you will see the progressive scanning represented by a p as in 720p or 1080p and to a minor extent interlaced scanning represented by an I as in 1080i.
As a platform, digital broadcasting will enhance the power of broadcasters and user interactivity like never before. Some other platforms and systems such as Blu-ray are already employing new user interactive features on Blu-ray discs.
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