If you are movie lover, chances are you've dreamed of having a home theater - the luxury of a big screen with the crystal clear image of a movie screen.

High Definition TV (HDTV) makes movie quality television a possibility. Traditional TV signals are analog - the intensity and color information for a program is sent on a scan line of the screen. The screen is made up of 525 scan lines for each image. The image is refreshed every 30^th of a second. Compare your analog signal resolution to your computer monitor resolution: television resolution is about 500 dots per inch, whereas the lowest computer monitor resolution is 640x480 pixels. Many computer monitors offer even greater resolution.

The digital programming is a much clearer, sharper picture. With digital television, the transmission of the signal is from the satellite dish directly to the satellite receiver that decodes the signal and broadcasts it to your TV set.

High Definition TV (HDTV) is an even higher quality transmission of the digital signal. HDTV transmits almost twice the lines of resolution as analog signals. HDTV offers a high quality signal combined with Dolby digital stereo sound.

Satellite broadcasters have to transmit their programming in the same bandwidth of regular analog programming (6 MHz). Broadcaster stations make use of compression software, similar to computer compression, to compress the signal into a manageable bandwidth. These files are MPEG-2 files.

MPEG-2, the compression and encoding software, records just enough of the image without making it look like something is missing. In subsequent frames, the software records the actual changes to the image. Any parts of the image that were not changed remain left in 'as-is' state from the previous frame. Some of the information that isn't recorded on the MPEG is information that the human eye would normally not detect.

MPEG transmission reduced the amount of data by about 55 to 1, so ultimately more data can be transmitted at one time. There are three formats of HDTV available.

• 720p - 1280x720 pixels progressive
• 1080i - 1920x1080 pixels interlaced
• 1080p - 1920x1080 pixels progressive

Obviously, part of the difference in transmission is the amount of pixels being displayed, but another difference is the difference between a progressive and interlaced signal.The differences between the two can be characterized by the way the image is displayed on the screen. With interlaced format, the information is filled in first with the odd lines on the screen and then the even lines. While the movement on the screen is so fast it's not easily detectable to a human eye, you may be aware of a 'flicker' quality with interlacing.

HDTV is changing the quality of broadcasting. Nowadays, we don't have to go to the movies to get the superior quality; we can have it in our own homes through the use of HDTV and a satellite TV signal.