Thanks to J. Carl Cooper, the man behind Pixel Instruments, for making this possible. Until then, the FCC is giving television broadcasters another channel to use for HDTV transmissions, starting in the major population centers. After the entire country has HDTV availability, the old transmissions will stop and their channels will be auctioned off or given to other services, like emergency communications. In HDTV, the picture is converted into digital data and compressed, like files on a computer. In the future, wavelets will be used for even greater compression.
Greater compression means that more details can be kept when signals are sent in one channel.
There is another way to compress the pictures, one that makes a visible picture on the current receivers. The digital data is divided into the part that we are already used to seeing and the finer details. Only the finer details are compressed digitally, and the old part is sent the way it is now. This is the part that will involve a change in the transmitters, as they do not currently put information in this part of the channel. By doing this, however, they will not have to buy a new transmitter for the extra channel or build a new antenna.