HDTV Explained
When television shows were first broadcast in Australia they used an analog TV signal which was delivered one of three ways to your house and then to the television. Many people received the analog signal through a roof mounted or television mounted antenna while other households had the analog signal broadcast to their homes through cable or via a satellite dish. Many households always had a battle with roof and television mounted antennas trying to get them in the just the right spot to receive all the channels with some picture clarity. Households with the cable or satellite options received a much better quality signal that was broadcast in digital and then converted to analog by either an external converter box or a television with this capability built in. Analog television has a maximum resolution of 720 x 480 pixels which is much less than its digital counterpart.
HDTV is part of the newer digital television technology. Digital has a number of video resolutions with the main two of these being 720p and 1080i. These two resolutions produce a picture in slightly different ways and have different pixel numbers. The 720p resolution gives you a total of 921,600 pixels per frame where as the 1080i gives you a higher 2,073,000 pixels per frame. Due to the pixel numbers of both of these resolutions, the pictures that are produced are sharper and clearer than the picture transmitted as an analog signal and then viewed on an analog television. The HDTV picture has more pixels to work with and the sharp, clear pictures are able to be produced due to the depth of colour and the larger numbers of pixels making up the images in the frame.
HDTV is transmitted as a digital signal which can only be picked up by a HD enabled television or an analog television that has a digital receiver and can convert the signal the analog before sending it through to the television. The picture quality will naturally be of a higher quality when the signal is viewed through a HDTV enabled television rather than changing the signal and viewing the picture on an analog television. The sound which goes with the picture is also transmitted as part of the HDTV signal and as with the picture, it is of a much higher quality than the analog sound however you need to have the appropriate speakers to take advantage of this feature.